Log using slf4j and java logging

91 files changed, 503 insertions, 434 deletions

diff --git a/debug.xml b/debug.xml
index ed3520cfc..887558323 100644
--- a/debug.xml
+++ b/debug.xml
@@ -12,6 +12,7 @@
 
     <entry key='geocoder.enable'>false</entry>
 
+    <entry key='logger.console'>true</entry>
     <entry key='logger.file'>target/tracker-server.log</entry>
 
     <entry key='database.driver'>org.h2.Driver</entry>
diff --git a/pom.xml b/pom.xml
index 27864a299..8d864cc66 100644
--- a/pom.xml
+++ b/pom.xml
@@ -23,11 +23,6 @@
             <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>log4j</groupId>
-            <artifactId>log4j</artifactId>
-            <version>1.2.17</version>
-        </dependency>
-        <dependency>
             <groupId>joda-time</groupId>
             <artifactId>joda-time</artifactId>
             <version>2.10</version>
@@ -75,7 +70,7 @@
         </dependency>
         <dependency>
             <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-simple</artifactId>
+            <artifactId>slf4j-jdk14</artifactId>
             <version>1.7.25</version>
         </dependency>
         <dependency>
@@ -132,6 +127,12 @@
             <groupId>org.liquibase</groupId>
             <artifactId>liquibase-core</artifactId>
             <version>3.6.2</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>ch.qos.logback</groupId>
+                    <artifactId>logback-classic</artifactId>
+                </exclusion>
+            </exclusions>
         </dependency>
         <dependency>
             <groupId>javax.mail</groupId>
diff --git a/src/org/traccar/BasePipelineFactory.java b/src/org/traccar/BasePipelineFactory.java
index 6269fb8cc..4cf5d7a98 100644
--- a/src/org/traccar/BasePipelineFactory.java
+++ b/src/org/traccar/BasePipelineFactory.java
@@ -29,6 +29,8 @@ import io.netty.channel.ChannelPromise;
 import io.netty.channel.socket.DatagramChannel;
 import io.netty.channel.socket.DatagramPacket;
 import io.netty.handler.timeout.IdleStateHandler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.events.CommandResultEventHandler;
 import org.traccar.events.DriverEventHandler;
 import org.traccar.events.FuelDropEventHandler;
@@ -38,7 +40,6 @@ import org.traccar.events.MaintenanceEventHandler;
 import org.traccar.events.MotionEventHandler;
 import org.traccar.events.OverspeedEventHandler;
 import org.traccar.events.AlertEventHandler;
-import org.traccar.helper.Log;
 import org.traccar.processing.ComputedAttributesHandler;
 import org.traccar.processing.CopyAttributesHandler;
 
@@ -46,6 +47,8 @@ import java.net.InetSocketAddress;
 
 public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(BasePipelineFactory.class);
+
     private final TrackerServer server;
     private int timeout;
 
@@ -155,7 +158,7 @@ public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {
             message.append(" HEX: ");
             message.append(ByteBufUtil.hexDump((ByteBuf) networkMessage.getMessage()));
 
-            Log.debug(message.toString());
+            LOGGER.debug(message.toString());
         }
 
     }
@@ -352,7 +355,7 @@ public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {
                 try {
                     pipeline.addLast("extraHandler." + i, (ChannelHandler) Class.forName(handlers[i]).newInstance());
                 } catch (ClassNotFoundException | InstantiationException | IllegalAccessException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         }
diff --git a/src/org/traccar/BaseProtocol.java b/src/org/traccar/BaseProtocol.java
index 62ee99946..4e5df329c 100644
--- a/src/org/traccar/BaseProtocol.java
+++ b/src/org/traccar/BaseProtocol.java
@@ -95,8 +95,12 @@ public abstract class BaseProtocol implements Protocol {
             if (command.getType().equals(Command.TYPE_CUSTOM)) {
                 Context.getSmsManager().sendMessageSync(destAddress, command.getString(Command.KEY_DATA), true);
             } else if (supportedTextCommands.contains(command.getType()) && textCommandEncoder != null) {
-                Context.getSmsManager().sendMessageSync(destAddress,
-                        (String) textCommandEncoder.encodeCommand(command), true);
+                String encodedCommand = (String) textCommandEncoder.encodeCommand(command);
+                if (encodedCommand != null) {
+                    Context.getSmsManager().sendMessageSync(destAddress, encodedCommand, true);
+                } else {
+                    throw new RuntimeException("Failed to encode command");
+                }
             } else {
                 throw new RuntimeException(
                         "Command " + command.getType() + " is not supported in protocol " + getName());
diff --git a/src/org/traccar/BaseProtocolDecoder.java b/src/org/traccar/BaseProtocolDecoder.java
index d9ab60e3a..e940d96c4 100644
--- a/src/org/traccar/BaseProtocolDecoder.java
+++ b/src/org/traccar/BaseProtocolDecoder.java
@@ -17,7 +17,8 @@ package org.traccar;
 
 import io.netty.channel.Channel;
 import io.netty.channel.socket.DatagramChannel;
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Device;
 import org.traccar.model.Position;
@@ -33,6 +34,8 @@ import java.sql.SQLException;
 
 public abstract class BaseProtocolDecoder extends ExtendedObjectDecoder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(BaseProtocolDecoder.class);
+
     private final Protocol protocol;
 
     public long addUnknownDevice(String uniqueId) {
@@ -49,7 +52,7 @@ public abstract class BaseProtocolDecoder extends ExtendedObjectDecoder {
         try {
             Context.getDeviceManager().addItem(device);
 
-            Log.info("Automatically registered device " + uniqueId);
+            LOGGER.info("Automatically registered device " + uniqueId);
 
             if (defaultGroupId != 0) {
                 Context.getPermissionsManager().refreshDeviceAndGroupPermissions();
@@ -58,7 +61,7 @@ public abstract class BaseProtocolDecoder extends ExtendedObjectDecoder {
 
             return device.getId();
         } catch (SQLException e) {
-            Log.warning(e);
+            LOGGER.warn(null, e);
             return 0;
         }
     }
@@ -107,7 +110,7 @@ public abstract class BaseProtocolDecoder extends ExtendedObjectDecoder {
             int timeZoneOffset = Context.getConfig().getInteger(getProtocolName() + ".timezone", 0);
             if (timeZoneOffset != 0) {
                 result.setRawOffset(timeZoneOffset * 1000);
-                Log.warning("Config parameter " + getProtocolName() + ".timezone is deprecated");
+                LOGGER.warn("Config parameter " + getProtocolName() + ".timezone is deprecated");
             }
         }
         return result;
@@ -131,7 +134,7 @@ public abstract class BaseProtocolDecoder extends ExtendedObjectDecoder {
                     }
                 }
             } catch (Exception e) {
-                Log.warning(e);
+                LOGGER.warn(null, e);
             }
             if (deviceId == 0 && Context.getConfig().getBoolean("database.registerUnknown")) {
                 return addUnknownDevice(uniqueIds[0]);
@@ -151,7 +154,7 @@ public abstract class BaseProtocolDecoder extends ExtendedObjectDecoder {
             if (remoteAddress != null) {
                 message.append(" (").append(((InetSocketAddress) remoteAddress).getHostString()).append(")");
             }
-            Log.warning(message.toString());
+            LOGGER.warn(message.toString());
         }
         return 0;
     }
diff --git a/src/org/traccar/BaseProtocolEncoder.java b/src/org/traccar/BaseProtocolEncoder.java
index ed71b5551..d7625e4b8 100644
--- a/src/org/traccar/BaseProtocolEncoder.java
+++ b/src/org/traccar/BaseProtocolEncoder.java
@@ -19,12 +19,15 @@ import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelOutboundHandlerAdapter;
 import io.netty.channel.ChannelPromise;
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.model.Command;
 import org.traccar.model.Device;
 
 public abstract class BaseProtocolEncoder extends ChannelOutboundHandlerAdapter {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(BaseProtocolEncoder.class);
+
     protected String getUniqueId(long deviceId) {
         return Context.getIdentityManager().getById(deviceId).getUniqueId();
     }
@@ -60,7 +63,7 @@ public abstract class BaseProtocolEncoder extends ChannelOutboundHandlerAdapter
             } else {
                 s.append("not sent");
             }
-            Log.info(s.toString());
+            LOGGER.info(s.toString());
 
             ctx.write(new NetworkMessage(encodedCommand, networkMessage.getRemoteAddress()), promise);
 
diff --git a/src/org/traccar/Context.java b/src/org/traccar/Context.java
index d607baf3e..9a8bb97a9 100644
--- a/src/org/traccar/Context.java
+++ b/src/org/traccar/Context.java
@@ -27,6 +27,8 @@ import com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider;
 import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;
 import org.apache.velocity.app.VelocityEngine;
 import org.eclipse.jetty.util.URIUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.database.CalendarManager;
 import org.traccar.database.CommandsManager;
 import org.traccar.database.AttributesManager;
@@ -87,9 +89,17 @@ import javax.ws.rs.client.ClientBuilder;
 
 public final class Context {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(Context.class);
+
+    public static final String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";
+
     private Context() {
     }
 
+    public static String getAppVersion() {
+        return Context.class.getPackage().getImplementationVersion();
+    }
+
     private static Config config;
 
     public static Config getConfig() {
@@ -398,7 +408,7 @@ public final class Context {
             try {
                 smsManager = (SmsManager) Class.forName(smsManagerClass).newInstance();
             } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
-                Log.warning("Error loading SMS Manager class : " + smsManagerClass, e);
+                LOGGER.warn("Error loading SMS Manager class : " + smsManagerClass, e);
             }
         }
 
diff --git a/src/org/traccar/DefaultDataHandler.java b/src/org/traccar/DefaultDataHandler.java
index 1ac3efc77..f62dca681 100644
--- a/src/org/traccar/DefaultDataHandler.java
+++ b/src/org/traccar/DefaultDataHandler.java
@@ -15,18 +15,21 @@
  */
 package org.traccar;
 
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.model.Position;
 
 public class DefaultDataHandler extends BaseDataHandler {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(DefaultDataHandler.class);
+
     @Override
     protected Position handlePosition(Position position) {
 
         try {
             Context.getDataManager().addObject(position);
         } catch (Exception error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
 
         return position;
diff --git a/src/org/traccar/FilterHandler.java b/src/org/traccar/FilterHandler.java
index 7ad68f386..b127e190a 100644
--- a/src/org/traccar/FilterHandler.java
+++ b/src/org/traccar/FilterHandler.java
@@ -16,13 +16,16 @@
 package org.traccar;
 
 import io.netty.channel.ChannelHandler;
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Position;
 
 @ChannelHandler.Sharable
 public class FilterHandler extends BaseDataHandler {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(FilterHandler.class);
+
     private boolean filterInvalid;
     private boolean filterZero;
     private boolean filterDuplicate;
@@ -236,7 +239,7 @@ public class FilterHandler extends BaseDataHandler {
             message.append("filters from device: ");
             message.append(Context.getIdentityManager().getById(position.getDeviceId()).getUniqueId());
 
-            Log.info(message.toString());
+            LOGGER.info(message.toString());
             return true;
         }
 
diff --git a/src/org/traccar/GeocoderHandler.java b/src/org/traccar/GeocoderHandler.java
index 0f3ba4731..72f164948 100644
--- a/src/org/traccar/GeocoderHandler.java
+++ b/src/org/traccar/GeocoderHandler.java
@@ -18,13 +18,16 @@ package org.traccar;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.geocoder.Geocoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Position;
 
 @ChannelHandler.Sharable
 public class GeocoderHandler extends ChannelInboundHandlerAdapter {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(GeocoderHandler.class);
+
     private final Geocoder geocoder;
     private final boolean processInvalidPositions;
     private final int geocoderReuseDistance;
@@ -63,7 +66,7 @@ public class GeocoderHandler extends ChannelInboundHandlerAdapter {
 
                     @Override
                     public void onFailure(Throwable e) {
-                        Log.warning("Geocoding failed", e);
+                        LOGGER.warn("Geocoding failed", e);
                         ctx.fireChannelRead(position);
                     }
                 });
diff --git a/src/org/traccar/GeolocationHandler.java b/src/org/traccar/GeolocationHandler.java
index 0c204dc0b..27043e94e 100644
--- a/src/org/traccar/GeolocationHandler.java
+++ b/src/org/traccar/GeolocationHandler.java
@@ -18,13 +18,16 @@ package org.traccar;
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.geolocation.GeolocationProvider;
 import org.traccar.model.Position;
 
 @ChannelHandler.Sharable
 public class GeolocationHandler extends ChannelInboundHandlerAdapter {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(GeolocationHandler.class);
+
     private final GeolocationProvider geolocationProvider;
     private final boolean processInvalidPositions;
 
@@ -60,7 +63,7 @@ public class GeolocationHandler extends ChannelInboundHandlerAdapter {
 
                     @Override
                     public void onFailure(Throwable e) {
-                        Log.warning(e);
+                        LOGGER.warn(null, e);
                         ctx.fireChannelRead(position);
                     }
                 });
diff --git a/src/org/traccar/Main.java b/src/org/traccar/Main.java
index 1e2db2693..fd1f07dca 100644
--- a/src/org/traccar/Main.java
+++ b/src/org/traccar/Main.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2012 - 2018 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,8 +15,14 @@
  */
 package org.traccar;
 
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
+import java.lang.management.ManagementFactory;
+import java.lang.management.MemoryMXBean;
+import java.lang.management.OperatingSystemMXBean;
+import java.lang.management.RuntimeMXBean;
+import java.nio.charset.Charset;
 import java.sql.SQLException;
 import java.util.Timer;
 import java.util.TimerTask;
@@ -24,16 +30,47 @@ import java.util.Locale;
 
 public final class Main {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(Main.class);
+
     private static final long CLEAN_PERIOD = 24 * 60 * 60 * 1000;
 
     private Main() {
     }
 
+    public static void logSystemInfo() {
+        try {
+            OperatingSystemMXBean operatingSystemBean = ManagementFactory.getOperatingSystemMXBean();
+            LOGGER.info("Operating system"
+                    + " name: " + operatingSystemBean.getName()
+                    + " version: " + operatingSystemBean.getVersion()
+                    + " architecture: " + operatingSystemBean.getArch());
+
+            RuntimeMXBean runtimeBean = ManagementFactory.getRuntimeMXBean();
+            LOGGER.info("Java runtime"
+                    + " name: " + runtimeBean.getVmName()
+                    + " vendor: " + runtimeBean.getVmVendor()
+                    + " version: " + runtimeBean.getVmVersion());
+
+            MemoryMXBean memoryBean = ManagementFactory.getMemoryMXBean();
+            LOGGER.info("Memory limit"
+                    + " heap: " + memoryBean.getHeapMemoryUsage().getMax() / (1024 * 1024) + "mb"
+                    + " non-heap: " + memoryBean.getNonHeapMemoryUsage().getMax() / (1024 * 1024) + "mb");
+
+            LOGGER.info("Character encoding: "
+                    + System.getProperty("file.encoding") + " charset: " + Charset.defaultCharset());
+
+        } catch (Exception error) {
+            LOGGER.warn("Failed to get system info");
+        }
+    }
+
     public static void main(String[] args) throws Exception {
         Locale.setDefault(Locale.ENGLISH);
 
         Context.init(args);
-        Log.info("Starting server...");
+        logSystemInfo();
+        LOGGER.info("Version: " + Context.getAppVersion());
+        LOGGER.info("Starting server...");
 
         Context.getServerManager().start();
         if (Context.getWebServer() != null) {
@@ -46,7 +83,7 @@ public final class Main {
                 try {
                     Context.getDataManager().clearHistory();
                 } catch (SQLException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         }, 0, CLEAN_PERIOD);
@@ -54,7 +91,7 @@ public final class Main {
         Runtime.getRuntime().addShutdownHook(new Thread() {
             @Override
             public void run() {
-                Log.info("Shutting down server...");
+                LOGGER.info("Shutting down server...");
 
                 if (Context.getWebServer() != null) {
                     Context.getWebServer().stop();
diff --git a/src/org/traccar/MainEventHandler.java b/src/org/traccar/MainEventHandler.java
index 49694aaff..b24edf28e 100644
--- a/src/org/traccar/MainEventHandler.java
+++ b/src/org/traccar/MainEventHandler.java
@@ -20,7 +20,8 @@ import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.socket.DatagramChannel;
 import io.netty.handler.timeout.IdleStateEvent;
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.model.Position;
 
 import java.sql.SQLException;
@@ -31,6 +32,8 @@ import java.util.Set;
 
 public class MainEventHandler extends ChannelInboundHandlerAdapter {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(GeocoderHandler.class);
+
     private final Set<String> connectionlessProtocols = new HashSet<>();
 
     public MainEventHandler() {
@@ -48,7 +51,7 @@ public class MainEventHandler extends ChannelInboundHandlerAdapter {
             try {
                 Context.getDeviceManager().updateLatestPosition(position);
             } catch (SQLException error) {
-                Log.warning(error);
+                LOGGER.warn(null, error);
             }
 
             String uniqueId = Context.getIdentityManager().getById(position.getDeviceId()).getUniqueId();
@@ -58,7 +61,7 @@ public class MainEventHandler extends ChannelInboundHandlerAdapter {
             s.append(formatChannel(ctx.channel())).append(" ");
             s.append("id: ").append(uniqueId);
             s.append(", time: ").append(
-                    new SimpleDateFormat(Log.DATE_FORMAT).format(position.getFixTime()));
+                    new SimpleDateFormat(Context.DATE_FORMAT).format(position.getFixTime()));
             s.append(", lat: ").append(String.format("%.5f", position.getLatitude()));
             s.append(", lon: ").append(String.format("%.5f", position.getLongitude()));
             if (position.getSpeed() > 0) {
@@ -72,7 +75,7 @@ public class MainEventHandler extends ChannelInboundHandlerAdapter {
             if (cmdResult != null) {
                 s.append(", result: ").append(cmdResult);
             }
-            Log.info(s.toString());
+            LOGGER.info(s.toString());
 
             Context.getStatisticsManager().registerMessageStored(position.getDeviceId());
         }
@@ -84,12 +87,12 @@ public class MainEventHandler extends ChannelInboundHandlerAdapter {
 
     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {
-        Log.info(formatChannel(ctx.channel()) + " connected");
+        LOGGER.info(formatChannel(ctx.channel()) + " connected");
     }
 
     @Override
     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
-        Log.info(formatChannel(ctx.channel()) + " disconnected");
+        LOGGER.info(formatChannel(ctx.channel()) + " disconnected");
         closeChannel(ctx.channel());
 
         BaseProtocolDecoder protocolDecoder = (BaseProtocolDecoder) ctx.pipeline().get("objectDecoder");
@@ -101,14 +104,14 @@ public class MainEventHandler extends ChannelInboundHandlerAdapter {
 
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
-        Log.warning(formatChannel(ctx.channel()) + " error", cause);
+        LOGGER.warn(formatChannel(ctx.channel()) + " error", cause);
         closeChannel(ctx.channel());
     }
 
     @Override
     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
         if (evt instanceof IdleStateEvent) {
-            Log.info(formatChannel(ctx.channel()) + " timed out");
+            LOGGER.info(formatChannel(ctx.channel()) + " timed out");
             closeChannel(ctx.channel());
         }
     }
diff --git a/src/org/traccar/ServerManager.java b/src/org/traccar/ServerManager.java
index a8da6d57e..a67f71be2 100644
--- a/src/org/traccar/ServerManager.java
+++ b/src/org/traccar/ServerManager.java
@@ -15,7 +15,8 @@
  */
 package org.traccar;
 
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.net.BindException;
@@ -33,6 +34,8 @@ import java.util.jar.JarFile;
 
 public class ServerManager {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(ServerManager.class);
+
     private final List<TrackerServer> serverList = new LinkedList<>();
     private final Map<String, BaseProtocol> protocolList = new ConcurrentHashMap<>();
 
@@ -84,7 +87,7 @@ public class ServerManager {
             try {
                 server.start();
             } catch (BindException e) {
-                Log.warning("One of the protocols is disabled due to port conflict");
+                LOGGER.warn("One of the protocols is disabled due to port conflict");
             }
         }
     }
diff --git a/src/org/traccar/WebDataHandler.java b/src/org/traccar/WebDataHandler.java
index 65b272df4..a8b4ab94a 100644
--- a/src/org/traccar/WebDataHandler.java
+++ b/src/org/traccar/WebDataHandler.java
@@ -16,8 +16,9 @@
 package org.traccar;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Device;
 import org.traccar.model.Position;
 
@@ -34,6 +35,8 @@ import java.util.TimeZone;
 
 public class WebDataHandler extends BaseDataHandler {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(WebDataHandler.class);
+
     private final String url;
     private final boolean json;
     private static final String KEY_POSITION = "position";
@@ -127,7 +130,7 @@ public class WebDataHandler extends BaseDataHandler {
             try {
                 Context.getClient().target(formatRequest(position)).request().async().get();
             } catch (UnsupportedEncodingException | JsonProcessingException e) {
-                Log.warning(e);
+                LOGGER.warn(null, e);
             }
         }
         return position;
diff --git a/src/org/traccar/api/AsyncSocket.java b/src/org/traccar/api/AsyncSocket.java
index 70523d253..783aeb740 100644
--- a/src/org/traccar/api/AsyncSocket.java
+++ b/src/org/traccar/api/AsyncSocket.java
@@ -18,9 +18,10 @@ package org.traccar.api;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import org.eclipse.jetty.websocket.api.Session;
 import org.eclipse.jetty.websocket.api.WebSocketAdapter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
 import org.traccar.database.ConnectionManager;
-import org.traccar.helper.Log;
 import org.traccar.model.Device;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
@@ -32,6 +33,8 @@ import java.util.Map;
 
 public class AsyncSocket extends WebSocketAdapter implements ConnectionManager.UpdateListener {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(AsyncSocket.class);
+
     private static final String KEY_DEVICES = "devices";
     private static final String KEY_POSITIONS = "positions";
     private static final String KEY_EVENTS = "events";
@@ -86,7 +89,7 @@ public class AsyncSocket extends WebSocketAdapter implements ConnectionManager.U
             try {
                 getRemote().sendString(Context.getObjectMapper().writeValueAsString(data), null);
             } catch (JsonProcessingException e) {
-                Log.warning(e);
+                LOGGER.warn(null, e);
             }
         }
     }
diff --git a/src/org/traccar/api/SecurityRequestFilter.java b/src/org/traccar/api/SecurityRequestFilter.java
index aace9f705..a76b34ad1 100644
--- a/src/org/traccar/api/SecurityRequestFilter.java
+++ b/src/org/traccar/api/SecurityRequestFilter.java
@@ -15,10 +15,11 @@
  */
 package org.traccar.api;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
 import org.traccar.api.resource.SessionResource;
 import org.traccar.helper.DataConverter;
-import org.traccar.helper.Log;
 import org.traccar.model.User;
 
 import javax.annotation.security.PermitAll;
@@ -35,6 +36,8 @@ import java.sql.SQLException;
 
 public class SecurityRequestFilter implements ContainerRequestFilter {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(SecurityRequestFilter.class);
+
     public static final String AUTHORIZATION_HEADER = "Authorization";
     public static final String WWW_AUTHENTICATE = "WWW-Authenticate";
     public static final String BASIC_REALM = "Basic realm=\"api\"";
@@ -93,7 +96,7 @@ public class SecurityRequestFilter implements ContainerRequestFilter {
             }
 
         } catch (SecurityException e) {
-            Log.warning(e);
+            LOGGER.warn(null, e);
         }
 
         if (securityContext != null) {
diff --git a/src/org/traccar/database/BaseObjectManager.java b/src/org/traccar/database/BaseObjectManager.java
index cc1dbde5f..7a17f8934 100644
--- a/src/org/traccar/database/BaseObjectManager.java
+++ b/src/org/traccar/database/BaseObjectManager.java
@@ -24,11 +24,14 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.model.BaseModel;
 
 public class BaseObjectManager<T extends BaseModel> {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(BaseObjectManager.class);
+
     private final DataManager dataManager;
 
     private Map<Long, T> items;
@@ -74,7 +77,7 @@ public class BaseObjectManager<T extends BaseModel> {
                     }
                 }
             } catch (SQLException error) {
-                Log.warning(error);
+                LOGGER.warn(null, error);
             }
         }
     }
diff --git a/src/org/traccar/database/CommandsManager.java b/src/org/traccar/database/CommandsManager.java
index c11f05f9b..daf154dc4 100644
--- a/src/org/traccar/database/CommandsManager.java
+++ b/src/org/traccar/database/CommandsManager.java
@@ -26,15 +26,18 @@ import java.util.Queue;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentLinkedQueue;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.BaseProtocol;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 import org.traccar.model.Typed;
 import org.traccar.model.Position;
 
 public class CommandsManager  extends ExtendedObjectManager<Command> {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(CommandsManager.class);
+
     private final Map<Long, Queue<Command>> deviceQueues = new ConcurrentHashMap<>();
 
     private boolean queueing;
@@ -126,7 +129,7 @@ public class CommandsManager  extends ExtendedObjectManager<Command> {
                 try {
                     result.add(new Typed(field.get(null).toString()));
                 } catch (IllegalArgumentException | IllegalAccessException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         }
diff --git a/src/org/traccar/database/ConnectionManager.java b/src/org/traccar/database/ConnectionManager.java
index ef2085295..3918bcc5f 100644
--- a/src/org/traccar/database/ConnectionManager.java
+++ b/src/org/traccar/database/ConnectionManager.java
@@ -18,11 +18,12 @@ package org.traccar.database;
 import io.netty.channel.Channel;
 import io.netty.util.Timeout;
 import io.netty.util.TimerTask;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
 import org.traccar.GlobalTimer;
 import org.traccar.Protocol;
 import org.traccar.events.OverspeedEventHandler;
-import org.traccar.helper.Log;
 import org.traccar.model.Device;
 import org.traccar.model.DeviceState;
 import org.traccar.model.Event;
@@ -40,6 +41,8 @@ import java.util.concurrent.TimeUnit;
 
 public class ConnectionManager {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(ConnectionManager.class);
+
     private static final long DEFAULT_TIMEOUT = 600;
 
     private final long deviceTimeout;
@@ -130,7 +133,7 @@ public class ConnectionManager {
         try {
             Context.getDeviceManager().updateDeviceStatus(device);
         } catch (SQLException error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
 
         updateDevice(device);
diff --git a/src/org/traccar/database/DataManager.java b/src/org/traccar/database/DataManager.java
index 06dd26b17..71db329bc 100644
--- a/src/org/traccar/database/DataManager.java
+++ b/src/org/traccar/database/DataManager.java
@@ -39,9 +39,10 @@ import liquibase.exception.LiquibaseException;
 import liquibase.resource.FileSystemResourceAccessor;
 import liquibase.resource.ResourceAccessor;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Config;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Attribute;
 import org.traccar.model.Device;
 import org.traccar.model.Driver;
@@ -65,6 +66,8 @@ import com.zaxxer.hikari.HikariDataSource;
 
 public class DataManager {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(DataManager.class);
+
     public static final String ACTION_SELECT_ALL = "selectAll";
     public static final String ACTION_SELECT = "select";
     public static final String ACTION_INSERT = "insert";
@@ -209,7 +212,7 @@ public class DataManager {
     private String getQuery(String key) {
         String query = config.getString(key);
         if (query == null) {
-            Log.info("Query not provided: " + key);
+            LOGGER.info("Query not provided: " + key);
         }
         return query;
     }
@@ -234,7 +237,7 @@ public class DataManager {
                 query = constructObjectQuery(action, clazz, extended);
                 config.setString(queryName, query);
             } else {
-                Log.info("Query not provided: " + queryName);
+                LOGGER.info("Query not provided: " + queryName);
             }
         }
 
@@ -261,7 +264,7 @@ public class DataManager {
                         property.equals(User.class) ? ManagedUser.class : property);
                 config.setString(queryName, query);
             } else {
-                Log.info("Query not provided: " + queryName);
+                LOGGER.info("Query not provided: " + queryName);
             }
         }
 
@@ -358,7 +361,8 @@ public class DataManager {
         long historyDays = config.getInteger("database.historyDays");
         if (historyDays != 0) {
             Date timeLimit = new Date(System.currentTimeMillis() - historyDays * 24 * 3600 * 1000);
-            Log.debug("Clearing history earlier than " + new SimpleDateFormat(Log.DATE_FORMAT).format(timeLimit));
+            LOGGER.debug(
+                    "Clearing history earlier than " + new SimpleDateFormat(Context.DATE_FORMAT).format(timeLimit));
             QueryBuilder.create(dataSource, getQuery("database.deletePositions"))
                     .setDate("serverTime", timeLimit)
                     .executeUpdate();
diff --git a/src/org/traccar/database/DeviceManager.java b/src/org/traccar/database/DeviceManager.java
index bc8894743..be413a108 100644
--- a/src/org/traccar/database/DeviceManager.java
+++ b/src/org/traccar/database/DeviceManager.java
@@ -25,9 +25,10 @@ import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Config;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Device;
 import org.traccar.model.DeviceState;
 import org.traccar.model.DeviceAccumulators;
@@ -37,6 +38,8 @@ import org.traccar.model.Server;
 
 public class DeviceManager extends BaseObjectManager<Device> implements IdentityManager, ManagableObjects {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(DeviceManager.class);
+
     public static final long DEFAULT_REFRESH_DELAY = 300;
 
     private final Config config;
@@ -93,7 +96,7 @@ public class DeviceManager extends BaseObjectManager<Device> implements Identity
             try {
                 updateDeviceCache(true);
             } catch (SQLException e) {
-                Log.warning(e);
+                LOGGER.warn(null, e);
             }
             result = super.getAllItems();
         }
@@ -228,7 +231,7 @@ public class DeviceManager extends BaseObjectManager<Device> implements Identity
                     positions.put(position.getDeviceId(), position);
                 }
             } catch (SQLException error) {
-                Log.warning(error);
+                LOGGER.warn(null, error);
             }
         }
     }
diff --git a/src/org/traccar/database/ExtendedObjectManager.java b/src/org/traccar/database/ExtendedObjectManager.java
index c9e349136..e48a3e802 100644
--- a/src/org/traccar/database/ExtendedObjectManager.java
+++ b/src/org/traccar/database/ExtendedObjectManager.java
@@ -23,8 +23,9 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Device;
 import org.traccar.model.Group;
 import org.traccar.model.Permission;
@@ -32,6 +33,8 @@ import org.traccar.model.BaseModel;
 
 public abstract class ExtendedObjectManager<T extends BaseModel> extends SimpleObjectManager<T> {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(ExtendedObjectManager.class);
+
     private final Map<Long, Set<Long>> deviceItems = new ConcurrentHashMap<>();
     private final Map<Long, Set<Long>> deviceItemsWithGroups = new ConcurrentHashMap<>();
     private final Map<Long, Set<Long>> groupItems = new ConcurrentHashMap<>();
@@ -105,7 +108,7 @@ public abstract class ExtendedObjectManager<T extends BaseModel> extends SimpleO
                 }
 
             } catch (SQLException | ClassNotFoundException error) {
-                Log.warning(error);
+                LOGGER.warn(null, error);
             }
         }
     }
diff --git a/src/org/traccar/database/GroupsManager.java b/src/org/traccar/database/GroupsManager.java
index 262f15519..eca39f972 100644
--- a/src/org/traccar/database/GroupsManager.java
+++ b/src/org/traccar/database/GroupsManager.java
@@ -21,12 +21,15 @@ import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Group;
 
 public class GroupsManager extends BaseObjectManager<Group> implements ManagableObjects {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(GroupsManager.class);
+
     private AtomicLong groupsLastUpdate = new AtomicLong();
     private final long dataRefreshDelay;
 
@@ -62,7 +65,7 @@ public class GroupsManager extends BaseObjectManager<Group> implements Managable
             try {
                 updateGroupCache(true);
             } catch (SQLException e) {
-                Log.warning(e);
+                LOGGER.warn(null, e);
             }
             result = super.getAllItems();
         }
diff --git a/src/org/traccar/database/LdapProvider.java b/src/org/traccar/database/LdapProvider.java
index eb975ad0f..612abe055 100644
--- a/src/org/traccar/database/LdapProvider.java
+++ b/src/org/traccar/database/LdapProvider.java
@@ -23,14 +23,17 @@ import javax.naming.directory.InitialDirContext;
 import javax.naming.directory.SearchControls;
 import javax.naming.directory.SearchResult;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Config;
-import org.traccar.helper.Log;
 import org.traccar.model.User;
 
 import java.util.Hashtable;
 
 public class LdapProvider {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(LdapProvider.class);
+
     private String url;
     private String searchBase;
     private String idAttribute;
@@ -85,7 +88,7 @@ public class LdapProvider {
                 if (results.hasMoreElements()) {
                     results.nextElement();
                     if (results.hasMoreElements()) {
-                        Log.warning("Matched multiple users for the accountName: " + accountName);
+                        LOGGER.warn("Matched multiple users for the accountName: " + accountName);
                         return false;
                     }
                     return true;
@@ -117,7 +120,7 @@ public class LdapProvider {
         if (results.hasMoreElements()) {
             searchResult = results.nextElement();
             if (results.hasMoreElements()) {
-                Log.warning("Matched multiple users for the accountName: " + accountName);
+                LOGGER.warn("Matched multiple users for the accountName: " + accountName);
                 return null;
             }
         }
@@ -155,7 +158,7 @@ public class LdapProvider {
             user.setLogin(accountName);
             user.setName(accountName);
             user.setEmail(accountName);
-            Log.warning(e);
+            LOGGER.warn(null, e);
         }
         return user;
     }
diff --git a/src/org/traccar/database/MediaManager.java b/src/org/traccar/database/MediaManager.java
index eb23d162f..62459cb5e 100644
--- a/src/org/traccar/database/MediaManager.java
+++ b/src/org/traccar/database/MediaManager.java
@@ -16,7 +16,8 @@
 package org.traccar.database;
 
 import io.netty.buffer.ByteBuf;
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.io.FileOutputStream;
@@ -31,6 +32,8 @@ import java.util.Date;
 
 public class MediaManager {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(MediaManager.class);
+
     private String path;
 
     public MediaManager(String path) {
@@ -60,7 +63,7 @@ public class MediaManager {
                 fileChannel.force(false);
                 return name;
             } catch (IOException e) {
-                Log.warning(e);
+                LOGGER.warn(null, e);
             }
         }
         return null;
diff --git a/src/org/traccar/database/NotificationManager.java b/src/org/traccar/database/NotificationManager.java
index 5dcb1d317..71a0a82e4 100644
--- a/src/org/traccar/database/NotificationManager.java
+++ b/src/org/traccar/database/NotificationManager.java
@@ -25,8 +25,9 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Calendar;
 import org.traccar.model.Event;
 import org.traccar.model.Notification;
@@ -35,6 +36,8 @@ import org.traccar.model.Typed;
 
 public class NotificationManager extends ExtendedObjectManager<Notification> {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(NotificationManager.class);
+
     private boolean geocodeOnRequest;
 
     public NotificationManager(DataManager dataManager) {
@@ -61,7 +64,7 @@ public class NotificationManager extends ExtendedObjectManager<Notification> {
         try {
             getDataManager().addObject(event);
         } catch (SQLException error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
 
         if (position != null && geocodeOnRequest && Context.getGeocoder() != null && position.getAddress() == null) {
@@ -114,7 +117,7 @@ public class NotificationManager extends ExtendedObjectManager<Notification> {
                 try {
                     types.add(new Typed(field.get(null).toString()));
                 } catch (IllegalArgumentException | IllegalAccessException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         }
diff --git a/src/org/traccar/database/PermissionsManager.java b/src/org/traccar/database/PermissionsManager.java
index 1c19f2374..c9d548fd1 100644
--- a/src/org/traccar/database/PermissionsManager.java
+++ b/src/org/traccar/database/PermissionsManager.java
@@ -15,8 +15,9 @@
  */
 package org.traccar.database;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Attribute;
 import org.traccar.model.BaseModel;
 import org.traccar.model.Calendar;
@@ -40,6 +41,8 @@ import java.util.Set;
 
 public class PermissionsManager {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(PermissionsManager.class);
+
     private final DataManager dataManager;
     private final UsersManager usersManager;
 
@@ -108,7 +111,7 @@ public class PermissionsManager {
         try {
             server = dataManager.getServer();
         } catch (SQLException error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
     }
 
@@ -143,7 +146,7 @@ public class PermissionsManager {
             }
 
         } catch (SQLException | ClassNotFoundException error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
 
         deviceUsers.clear();
diff --git a/src/org/traccar/database/QueryBuilder.java b/src/org/traccar/database/QueryBuilder.java
index af33458a8..8075223f2 100644
--- a/src/org/traccar/database/QueryBuilder.java
+++ b/src/org/traccar/database/QueryBuilder.java
@@ -16,8 +16,9 @@
 package org.traccar.database;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.MiscFormatter;
 import org.traccar.model.Permission;
 
@@ -43,6 +44,8 @@ import java.util.Map;
 
 public final class QueryBuilder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(QueryBuilder.class);
+
     private final Map<String, List<Integer>> indexMap = new HashMap<>();
     private Connection connection;
     private PreparedStatement statement;
@@ -289,7 +292,7 @@ public final class QueryBuilder {
                         }
                     }
                 } catch (IllegalAccessException | InvocationTargetException | JsonProcessingException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         }
@@ -321,7 +324,7 @@ public final class QueryBuilder {
                     try {
                         method.invoke(object, resultSet.getBoolean(name));
                     } catch (IllegalAccessException | InvocationTargetException error) {
-                        Log.warning(error);
+                        LOGGER.warn(null, error);
                     }
                 }
             });
@@ -332,7 +335,7 @@ public final class QueryBuilder {
                     try {
                         method.invoke(object, resultSet.getInt(name));
                     } catch (IllegalAccessException | InvocationTargetException error) {
-                        Log.warning(error);
+                        LOGGER.warn(null, error);
                     }
                 }
             });
@@ -343,7 +346,7 @@ public final class QueryBuilder {
                     try {
                         method.invoke(object, resultSet.getLong(name));
                     } catch (IllegalAccessException | InvocationTargetException error) {
-                        Log.warning(error);
+                        LOGGER.warn(null, error);
                     }
                 }
             });
@@ -354,7 +357,7 @@ public final class QueryBuilder {
                     try {
                         method.invoke(object, resultSet.getDouble(name));
                     } catch (IllegalAccessException | InvocationTargetException error) {
-                        Log.warning(error);
+                        LOGGER.warn(null, error);
                     }
                 }
             });
@@ -365,7 +368,7 @@ public final class QueryBuilder {
                     try {
                         method.invoke(object, resultSet.getString(name));
                     } catch (IllegalAccessException | InvocationTargetException error) {
-                        Log.warning(error);
+                        LOGGER.warn(null, error);
                     }
                 }
             });
@@ -379,7 +382,7 @@ public final class QueryBuilder {
                             method.invoke(object, new Date(timestamp.getTime()));
                         }
                     } catch (IllegalAccessException | InvocationTargetException error) {
-                        Log.warning(error);
+                        LOGGER.warn(null, error);
                     }
                 }
             });
@@ -390,7 +393,7 @@ public final class QueryBuilder {
                     try {
                         method.invoke(object, resultSet.getBytes(name));
                     } catch (IllegalAccessException | InvocationTargetException error) {
-                        Log.warning(error);
+                        LOGGER.warn(null, error);
                     }
                 }
             });
@@ -403,7 +406,7 @@ public final class QueryBuilder {
                         try {
                             method.invoke(object, Context.getObjectMapper().readValue(value, parameterType));
                         } catch (InvocationTargetException | IllegalAccessException | IOException error) {
-                            Log.warning(error);
+                            LOGGER.warn(null, error);
                         }
                     }
                 }
diff --git a/src/org/traccar/database/SimpleObjectManager.java b/src/org/traccar/database/SimpleObjectManager.java
index 0b4d11378..bf790da29 100644
--- a/src/org/traccar/database/SimpleObjectManager.java
+++ b/src/org/traccar/database/SimpleObjectManager.java
@@ -22,8 +22,9 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.BaseModel;
 import org.traccar.model.Permission;
 import org.traccar.model.User;
@@ -31,6 +32,8 @@ import org.traccar.model.User;
 public abstract class SimpleObjectManager<T extends BaseModel> extends BaseObjectManager<T>
         implements ManagableObjects {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(SimpleObjectManager.class);
+
     private Map<Long, Set<Long>> userItems;
 
     protected SimpleObjectManager(DataManager dataManager, Class<T> baseClass) {
@@ -77,7 +80,7 @@ public abstract class SimpleObjectManager<T extends BaseModel> extends BaseObjec
                     getUserItems(permission.getOwnerId()).add(permission.getPropertyId());
                 }
             } catch (SQLException | ClassNotFoundException error) {
-                Log.warning(error);
+                LOGGER.warn(null, error);
             }
         }
     }
diff --git a/src/org/traccar/database/StatisticsManager.java b/src/org/traccar/database/StatisticsManager.java
index 452cdffa0..f6ede0a12 100644
--- a/src/org/traccar/database/StatisticsManager.java
+++ b/src/org/traccar/database/StatisticsManager.java
@@ -16,8 +16,9 @@
 package org.traccar.database;
 
 import org.joda.time.format.ISODateTimeFormat;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Statistics;
 
 import javax.ws.rs.client.Entity;
@@ -31,6 +32,8 @@ import java.util.concurrent.atomic.AtomicInteger;
 
 public class StatisticsManager {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(StatisticsManager.class);
+
     private static final int SPLIT_MODE = Calendar.DAY_OF_MONTH;
 
     private AtomicInteger lastUpdate = new AtomicInteger(Calendar.getInstance().get(SPLIT_MODE));
@@ -64,7 +67,7 @@ public class StatisticsManager {
             try {
                 Context.getDataManager().addObject(statistics);
             } catch (SQLException e) {
-                Log.warning(e);
+                LOGGER.warn(null, e);
             }
 
             String url = Context.getConfig().getString("server.statistics");
@@ -72,7 +75,7 @@ public class StatisticsManager {
                 String time = ISODateTimeFormat.dateTime().print(statistics.getCaptureTime().getTime());
 
                 Form form = new Form();
-                form.param("version", Log.getAppVersion());
+                form.param("version", Context.getAppVersion());
                 form.param("captureTime", time);
                 form.param("activeUsers", String.valueOf(statistics.getActiveUsers()));
                 form.param("activeDevices", String.valueOf(statistics.getActiveDevices()));
diff --git a/src/org/traccar/geocoder/JsonGeocoder.java b/src/org/traccar/geocoder/JsonGeocoder.java
index 36a3acb76..c0c789a51 100644
--- a/src/org/traccar/geocoder/JsonGeocoder.java
+++ b/src/org/traccar/geocoder/JsonGeocoder.java
@@ -15,8 +15,9 @@
  */
 package org.traccar.geocoder;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 
 import javax.json.JsonObject;
 import javax.ws.rs.ClientErrorException;
@@ -29,6 +30,8 @@ import java.util.Map;
 
 public abstract class JsonGeocoder implements Geocoder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(JsonGeocoder.class);
+
     private final String url;
     private final AddressFormat addressFormat;
 
@@ -64,7 +67,7 @@ public abstract class JsonGeocoder implements Geocoder {
             if (callback != null) {
                 callback.onFailure(new GeocoderException("Empty address"));
             } else {
-                Log.warning("Empty address");
+                LOGGER.warn("Empty address");
             }
         }
         return null;
@@ -102,7 +105,7 @@ public abstract class JsonGeocoder implements Geocoder {
             try {
                 return handleResponse(latitude, longitude, request.get(JsonObject.class), null);
             } catch (ClientErrorException e) {
-                Log.warning(e);
+                LOGGER.warn(null, e);
             }
         }
         return null;
diff --git a/src/org/traccar/helper/Log.java b/src/org/traccar/helper/Log.java
index a22e4bde2..42cd07cef 100644
--- a/src/org/traccar/helper/Log.java
+++ b/src/org/traccar/helper/Log.java
@@ -15,126 +15,137 @@
  */
 package org.traccar.helper;
 
-import org.apache.log4j.Appender;
-import org.apache.log4j.DailyRollingFileAppender;
-import org.apache.log4j.Layout;
-import org.apache.log4j.Level;
-import org.apache.log4j.LogManager;
-import org.apache.log4j.Logger;
-import org.apache.log4j.PatternLayout;
-import org.apache.log4j.varia.NullAppender;
 import org.traccar.Config;
 
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileWriter;
 import java.io.IOException;
-import java.lang.management.ManagementFactory;
-import java.lang.management.MemoryMXBean;
-import java.lang.management.OperatingSystemMXBean;
-import java.lang.management.RuntimeMXBean;
-import java.nio.charset.Charset;
+import java.io.Writer;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.logging.ConsoleHandler;
+import java.util.logging.Formatter;
+import java.util.logging.Handler;
+import java.util.logging.Level;
+import java.util.logging.LogRecord;
+import java.util.logging.Logger;
 
 public final class Log {
 
     private Log() {
     }
 
-    public static final String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";
-
-    private static final String LOGGER_NAME = "traccar";
-
     private static final String STACK_PACKAGE = "org.traccar";
     private static final int STACK_LIMIT = 3;
 
-    private static Logger logger = null;
-
-    public static String getAppVersion() {
-        return Log.class.getPackage().getImplementationVersion();
-    }
+    private static class RollingFileHandler extends Handler {
 
-    public static void setupLogger(Config config) throws IOException {
+        private String name;
+        private String suffix;
+        private Writer writer;
 
-        Layout layout = new PatternLayout("%d{" + DATE_FORMAT + "} %5p: %m%n");
+        RollingFileHandler(String name) {
+            this.name = name;
+        }
 
-        Appender appender = new DailyRollingFileAppender(
-                layout, config.getString("logger.file"), "'.'yyyyMMdd");
+        @Override
+        public synchronized void publish(LogRecord record) {
+            if (isLoggable(record)) {
+                try {
+                    String suffix = new SimpleDateFormat("yyyyMMdd").format(new Date(record.getMillis()));
+                    if (writer != null && !suffix.equals(this.suffix)) {
+                        writer.close();
+                        writer = null;
+                        new File(name).renameTo(new File(name + "." + this.suffix));
+                    }
+                    if (writer == null) {
+                        this.suffix = suffix;
+                        writer = new BufferedWriter(new FileWriter(name));
+                    }
+                    writer.write(getFormatter().format(record));
+                    writer.flush();
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        }
 
-        LogManager.resetConfiguration();
-        LogManager.getRootLogger().addAppender(new NullAppender());
+        @Override
+        public void flush() {
+            if (writer != null) {
+                try {
+                    writer.flush();
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        }
 
-        logger = Logger.getLogger(LOGGER_NAME);
-        logger.addAppender(appender);
-        logger.setLevel(Level.toLevel(config.getString("logger.level"), Level.ALL));
+        @Override
+        public void close() throws SecurityException {
+            if (writer != null) {
+                try {
+                    writer.close();
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        }
 
-        Log.logSystemInfo();
-        Log.info("Version: " + getAppVersion());
     }
 
-    public static Logger getLogger() {
-        if (logger == null) {
-            logger = Logger.getLogger(LOGGER_NAME);
-            logger.setLevel(Level.OFF);
+    public static class LogFormatter extends Formatter {
+
+        private static String formatLevel(Level level) {
+            switch (level.getName()) {
+                case "FINEST":
+                    return "TRACE";
+                case "FINER":
+                case "FINE":
+                    return "DEBUG";
+                case "INFO":
+                    return "INFO";
+                case "WARNING":
+                    return "WARN";
+                case "SEVERE":
+                default:
+                    return "ERROR";
+            }
         }
-        return logger;
-    }
 
-    public static void logSystemInfo() {
-        try {
-            OperatingSystemMXBean operatingSystemBean = ManagementFactory.getOperatingSystemMXBean();
-            Log.info("Operating system"
-                    + " name: " + operatingSystemBean.getName()
-                    + " version: " + operatingSystemBean.getVersion()
-                    + " architecture: " + operatingSystemBean.getArch());
-
-            RuntimeMXBean runtimeBean = ManagementFactory.getRuntimeMXBean();
-            Log.info("Java runtime"
-                    + " name: " + runtimeBean.getVmName()
-                    + " vendor: " + runtimeBean.getVmVendor()
-                    + " version: " + runtimeBean.getVmVersion());
-
-            MemoryMXBean memoryBean = ManagementFactory.getMemoryMXBean();
-            Log.info("Memory limit"
-                    + " heap: " + memoryBean.getHeapMemoryUsage().getMax() / (1024 * 1024) + "mb"
-                    + " non-heap: " + memoryBean.getNonHeapMemoryUsage().getMax() / (1024 * 1024) + "mb");
-
-            Log.info("Character encoding: "
-                    + System.getProperty("file.encoding") + " charset: " + Charset.defaultCharset());
-
-        } catch (Exception error) {
-            Log.warning("Failed to get system info");
-        }
-    }
+        @Override
+        public String format(LogRecord record) {
+            StringBuilder message = new StringBuilder(record.getMessage());
 
-    public static void error(String msg) {
-        getLogger().error(msg);
-    }
+            if (record.getThrown() != null) {
+                message.append(" - ").append(exceptionStack(record.getThrown()));
+            }
 
-    public static void warning(String msg) {
-        getLogger().warn(msg);
-    }
+            return String.format("%1$tF %1$tT %2$5s: %3$s%n",
+                    new Date(record.getMillis()), formatLevel(record.getLevel()), message.toString());
+        }
 
-    public static void warning(Throwable exception) {
-        warning(null, exception);
     }
 
-    public static void warning(String msg, Throwable exception) {
-        StringBuilder s = new StringBuilder();
-        if (msg != null) {
-            s.append(msg);
+    public static void setupLogger(Config config) throws IOException {
+
+        Logger rootLogger = Logger.getLogger("");
+        for (Handler handler : rootLogger.getHandlers()) {
+            rootLogger.removeHandler(handler);
         }
-        if (exception != null) {
-            if (msg != null) {
-                s.append(" - ");
-            }
-            s.append(exceptionStack(exception));
+
+        Handler handler;
+        if (config.getBoolean("logger.console")) {
+            handler = new ConsoleHandler();
+        } else {
+            handler = new RollingFileHandler(config.getString("logger.file"));
         }
-        getLogger().warn(s.toString());
-    }
 
-    public static void info(String msg) {
-        getLogger().info(msg);
-    }
+        handler.setFormatter(new LogFormatter());
+        handler.setLevel(Level.parse(config.getString("logger.level").toUpperCase()));
 
-    public static void debug(String msg) {
-        getLogger().debug(msg);
+        rootLogger.addHandler(handler);
     }
 
     public static String exceptionStack(Throwable exception) {
diff --git a/src/org/traccar/helper/LogAction.java b/src/org/traccar/helper/LogAction.java
index 2f575537d..db13337b8 100644
--- a/src/org/traccar/helper/LogAction.java
+++ b/src/org/traccar/helper/LogAction.java
@@ -18,10 +18,14 @@ package org.traccar.helper;
 
 import java.beans.Introspector;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.model.BaseModel;
 
 public final class LogAction {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(LogAction.class);
+
     private LogAction() {
     }
 
@@ -71,26 +75,25 @@ public final class LogAction {
     }
 
     public static void resetDeviceAccumulators(long userId, long deviceId) {
-        log(String.format(PATTERN_DEVICE_ACCUMULATORS, userId, ACTION_DEVICE_ACCUMULATORS, deviceId));
+        LOGGER.info(String.format(
+                PATTERN_DEVICE_ACCUMULATORS, userId, ACTION_DEVICE_ACCUMULATORS, deviceId));
     }
 
     private static void logObjectAction(String action, long userId, Class<?> clazz, long objectId) {
-        log(String.format(PATTERN_OBJECT, userId, action, Introspector.decapitalize(clazz.getSimpleName()), objectId));
+        LOGGER.info(String.format(
+                PATTERN_OBJECT, userId, action, Introspector.decapitalize(clazz.getSimpleName()), objectId));
     }
 
     private static void logLinkAction(String action, long userId,
             Class<?> owner, long ownerId, Class<?> property, long propertyId) {
-        log(String.format(PATTERN_LINK, userId, action,
+        LOGGER.info(String.format(
+                PATTERN_LINK, userId, action,
                 Introspector.decapitalize(owner.getSimpleName()), ownerId,
                 Introspector.decapitalize(property.getSimpleName()), propertyId));
     }
 
     private static void logLoginAction(String action, long userId) {
-        log(String.format(PATTERN_LOGIN, userId, action));
-    }
-
-    private static void log(String msg) {
-        Log.info(msg);
+        LOGGER.info(String.format(PATTERN_LOGIN, userId, action));
     }
 
 }
diff --git a/src/org/traccar/helper/PatternUtil.java b/src/org/traccar/helper/PatternUtil.java
index 1bbb166a6..53eeb0b24 100644
--- a/src/org/traccar/helper/PatternUtil.java
+++ b/src/org/traccar/helper/PatternUtil.java
@@ -15,6 +15,9 @@
  */
 package org.traccar.helper;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.lang.management.ManagementFactory;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -22,6 +25,8 @@ import java.util.regex.PatternSyntaxException;
 
 public final class PatternUtil {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(PatternUtil.class);
+
     private PatternUtil() {
     }
 
@@ -66,7 +71,7 @@ public final class PatternUtil {
                     result.stringTail = input.substring(matcher.group(1).length());
                 }
             } catch (PatternSyntaxException error) {
-                Log.warning(error);
+                LOGGER.warn(null, error);
             }
         }
 
diff --git a/src/org/traccar/model/Server.java b/src/org/traccar/model/Server.java
index c6161397b..66aa7ee75 100644
--- a/src/org/traccar/model/Server.java
+++ b/src/org/traccar/model/Server.java
@@ -15,14 +15,14 @@
  */
 package org.traccar.model;
 
+import org.traccar.Context;
 import org.traccar.database.QueryIgnore;
-import org.traccar.helper.Log;
 
 public class Server extends ExtendedModel {
 
     @QueryIgnore
     public String getVersion() {
-        return Log.getAppVersion();
+        return Context.getAppVersion();
     }
 
     public void setVersion(String version) {
diff --git a/src/org/traccar/notification/NotificationFormatter.java b/src/org/traccar/notification/NotificationFormatter.java
index c011403c5..57be29b31 100644
--- a/src/org/traccar/notification/NotificationFormatter.java
+++ b/src/org/traccar/notification/NotificationFormatter.java
@@ -26,8 +26,9 @@ import org.apache.velocity.VelocityContext;
 import org.apache.velocity.exception.ResourceNotFoundException;
 import org.apache.velocity.tools.generic.DateTool;
 import org.apache.velocity.tools.generic.NumberTool;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Device;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
@@ -36,6 +37,8 @@ import org.traccar.reports.ReportUtils;
 
 public final class NotificationFormatter {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(NotificationFormatter.class);
+
     private NotificationFormatter() {
     }
 
@@ -81,7 +84,7 @@ public final class NotificationFormatter {
             templateFilePath = Paths.get(path, event.getType() + ".vm").toString();
             template = Context.getVelocityEngine().getTemplate(templateFilePath, StandardCharsets.UTF_8.name());
         } catch (ResourceNotFoundException error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
             templateFilePath = Paths.get(path, "unknown.vm").toString();
             template = Context.getVelocityEngine().getTemplate(templateFilePath, StandardCharsets.UTF_8.name());
         }
diff --git a/src/org/traccar/notification/NotificatorManager.java b/src/org/traccar/notification/NotificatorManager.java
index a3b13ef25..7e8a9dd0e 100644
--- a/src/org/traccar/notification/NotificatorManager.java
+++ b/src/org/traccar/notification/NotificatorManager.java
@@ -21,14 +21,17 @@ import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Typed;
 import org.traccar.notificators.NotificatorNull;
 import org.traccar.notificators.Notificator;
 
 public final class NotificatorManager {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(NotificatorManager.class);
+
     private static final String DEFAULT_WEB_NOTIFICATOR = "org.traccar.notificators.NotificatorWeb";
     private static final String DEFAULT_MAIL_NOTIFICATOR = "org.traccar.notificators.NotificatorMail";
     private static final String DEFAULT_SMS_NOTIFICATOR = "org.traccar.notificators.NotificatorSms";
@@ -58,7 +61,7 @@ public final class NotificatorManager {
             try {
                 notificators.put(type, (Notificator) Class.forName(className).newInstance());
             } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
-                Log.error("Unable to load notificator class for " + type + " " + className + " " + e.getMessage());
+                LOGGER.warn("Unable to load notificator class for " + type + " " + className + " " + e.getMessage());
             }
         }
     }
@@ -66,7 +69,7 @@ public final class NotificatorManager {
     public Notificator getNotificator(String type) {
         final Notificator notificator = notificators.get(type);
         if (notificator == null) {
-            Log.error("No notificator configured for type : " + type);
+            LOGGER.warn("No notificator configured for type : " + type);
             return NULL_NOTIFICATOR;
         }
         return notificator;
diff --git a/src/org/traccar/notificators/Notificator.java b/src/org/traccar/notificators/Notificator.java
index de9817c9f..c3fad1607 100644
--- a/src/org/traccar/notificators/Notificator.java
+++ b/src/org/traccar/notificators/Notificator.java
@@ -16,20 +16,23 @@
  */
 package org.traccar.notificators;
 
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.notification.MessageException;
 
 public abstract class Notificator {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(Notificator.class);
+
     public void sendAsync(final long userId, final Event event, final Position position) {
         new Thread(new Runnable() {
             public void run() {
                 try {
                     sendSync(userId, event, position);
                 } catch (MessageException | InterruptedException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         }).start();
diff --git a/src/org/traccar/notificators/NotificatorMail.java b/src/org/traccar/notificators/NotificatorMail.java
index cf786ffc4..7aa1a2968 100644
--- a/src/org/traccar/notificators/NotificatorMail.java
+++ b/src/org/traccar/notificators/NotificatorMail.java
@@ -26,8 +26,9 @@ import javax.mail.internet.InternetAddress;
 import javax.mail.internet.MimeMessage;
 import java.util.Date;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.model.User;
@@ -38,6 +39,8 @@ import org.traccar.notification.PropertiesProvider;
 
 public final class NotificatorMail extends Notificator {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(NotificatorMail.class);
+
     private static Properties getProperties(PropertiesProvider provider) {
         Properties properties = new Properties();
         String host = provider.getString("mail.smtp.host");
@@ -97,7 +100,7 @@ public final class NotificatorMail extends Notificator {
             properties = getProperties(new PropertiesProvider(Context.getConfig()));
         }
         if (!properties.containsKey("mail.smtp.host")) {
-            Log.warning("No SMTP configuration found");
+            LOGGER.warn("No SMTP configuration found");
             return;
         }
 
diff --git a/src/org/traccar/notificators/NotificatorNull.java b/src/org/traccar/notificators/NotificatorNull.java
index 2120cda0c..9364336be 100644
--- a/src/org/traccar/notificators/NotificatorNull.java
+++ b/src/org/traccar/notificators/NotificatorNull.java
@@ -16,19 +16,23 @@
  */
 package org.traccar.notificators;
 
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 
 public final class NotificatorNull extends Notificator {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(NotificatorNull.class);
+
     @Override
     public void sendAsync(long userId, Event event, Position position) {
-        Log.warning("You are using null notificatior, please check your configuration, notification not sent");
+        LOGGER.warn("You are using null notificatior, please check your configuration, notification not sent");
     }
 
     @Override
     public void sendSync(long userId, Event event, Position position) {
-        Log.warning("You are using null notificatior, please check your configuration, notification not sent");
+        LOGGER.warn("You are using null notificatior, please check your configuration, notification not sent");
     }
+
 }
diff --git a/src/org/traccar/processing/ComputedAttributesHandler.java b/src/org/traccar/processing/ComputedAttributesHandler.java
index a4edcc460..d4090e709 100644
--- a/src/org/traccar/processing/ComputedAttributesHandler.java
+++ b/src/org/traccar/processing/ComputedAttributesHandler.java
@@ -29,9 +29,10 @@ import io.netty.channel.ChannelHandler;
 import org.apache.commons.jexl2.JexlEngine;
 import org.apache.commons.jexl2.JexlException;
 import org.apache.commons.jexl2.MapContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.BaseDataHandler;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Attribute;
 import org.traccar.model.Device;
 import org.traccar.model.Position;
@@ -39,6 +40,8 @@ import org.traccar.model.Position;
 @ChannelHandler.Sharable
 public class ComputedAttributesHandler extends BaseDataHandler {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(ComputedAttributesHandler.class);
+
     private JexlEngine engine;
 
     private boolean mapDeviceAttributes;
@@ -77,7 +80,7 @@ public class ComputedAttributesHandler extends BaseDataHandler {
                         }
                     }
                 } catch (IllegalAccessException | InvocationTargetException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         }
@@ -98,7 +101,7 @@ public class ComputedAttributesHandler extends BaseDataHandler {
                 try {
                     result = computeAttribute(attribute, position);
                 } catch (JexlException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
                 if (result != null) {
                     try {
@@ -115,7 +118,7 @@ public class ComputedAttributesHandler extends BaseDataHandler {
                                 position.getAttributes().put(attribute.getAttribute(), result.toString());
                         }
                     } catch (ClassCastException error) {
-                        Log.warning(error);
+                        LOGGER.warn(null, error);
                     }
                 }
             }
diff --git a/src/org/traccar/protocol/AdmProtocolEncoder.java b/src/org/traccar/protocol/AdmProtocolEncoder.java
index bcbf8a2f1..e76bc2ddc 100644
--- a/src/org/traccar/protocol/AdmProtocolEncoder.java
+++ b/src/org/traccar/protocol/AdmProtocolEncoder.java
@@ -17,7 +17,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class AdmProtocolEncoder extends StringProtocolEncoder {
@@ -33,11 +32,8 @@ public class AdmProtocolEncoder extends StringProtocolEncoder {
                 return formatCommand(command, "{%s}\r\n", Command.KEY_DATA);
 
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/AplicomProtocolDecoder.java b/src/org/traccar/protocol/AplicomProtocolDecoder.java
index bfd92e0ad..bb821893a 100644
--- a/src/org/traccar/protocol/AplicomProtocolDecoder.java
+++ b/src/org/traccar/protocol/AplicomProtocolDecoder.java
@@ -18,11 +18,12 @@ package org.traccar.protocol;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufUtil;
 import io.netty.channel.Channel;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.Context;
 import org.traccar.DeviceSession;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Position;
 
@@ -33,6 +34,8 @@ import java.util.Date;
 
 public class AplicomProtocolDecoder extends BaseProtocolDecoder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(AplicomProtocolDecoder.class);
+
     public AplicomProtocolDecoder(AplicomProtocol protocol) {
         super(protocol);
     }
@@ -195,7 +198,7 @@ public class AplicomProtocolDecoder extends BaseProtocolDecoder {
                     }
                     break;
                 default:
-                    Log.warning(new UnsupportedOperationException());
+                    LOGGER.warn(null, new UnsupportedOperationException());
                     break;
             }
         }
diff --git a/src/org/traccar/protocol/AstraProtocolDecoder.java b/src/org/traccar/protocol/AstraProtocolDecoder.java
index c386c7757..7c6a8fc1e 100644
--- a/src/org/traccar/protocol/AstraProtocolDecoder.java
+++ b/src/org/traccar/protocol/AstraProtocolDecoder.java
@@ -18,12 +18,13 @@ package org.traccar.protocol;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
 import org.traccar.NetworkMessage;
 import org.traccar.helper.BitUtil;
 import org.traccar.helper.DateBuilder;
-import org.traccar.helper.Log;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Position;
 
@@ -34,6 +35,8 @@ import java.util.List;
 
 public class AstraProtocolDecoder extends BaseProtocolDecoder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(AstraProtocolDecoder.class);
+
     public AstraProtocolDecoder(AstraProtocol protocol) {
         super(protocol);
     }
@@ -111,7 +114,7 @@ public class AstraProtocolDecoder extends BaseProtocolDecoder {
             }
 
             if (BitUtil.check(status, 6)) {
-                Log.warning("Extension data is not supported");
+                LOGGER.warn("Extension data is not supported");
                 return position;
             }
 
diff --git a/src/org/traccar/protocol/AtrackProtocolEncoder.java b/src/org/traccar/protocol/AtrackProtocolEncoder.java
index 1aa580435..1e085cb26 100644
--- a/src/org/traccar/protocol/AtrackProtocolEncoder.java
+++ b/src/org/traccar/protocol/AtrackProtocolEncoder.java
@@ -17,7 +17,6 @@ package org.traccar.protocol;
 
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -32,11 +31,8 @@ public class AtrackProtocolEncoder extends BaseProtocolEncoder {
                 return Unpooled.copiedBuffer(
                         command.getString(Command.KEY_DATA) + "\r\n", StandardCharsets.US_ASCII);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/CarcellProtocolEncoder.java b/src/org/traccar/protocol/CarcellProtocolEncoder.java
index 0846949c4..e8f0081a0 100644
--- a/src/org/traccar/protocol/CarcellProtocolEncoder.java
+++ b/src/org/traccar/protocol/CarcellProtocolEncoder.java
@@ -16,7 +16,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class CarcellProtocolEncoder extends StringProtocolEncoder {
@@ -30,11 +29,8 @@ public class CarcellProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_ENGINE_RESUME:
                 return formatCommand(command, "$SRVCMD,{%s},BD#\r\n", Command.KEY_UNIQUE_ID);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/CastelProtocolEncoder.java b/src/org/traccar/protocol/CastelProtocolEncoder.java
index dde8ac11f..e1f78e7c1 100644
--- a/src/org/traccar/protocol/CastelProtocolEncoder.java
+++ b/src/org/traccar/protocol/CastelProtocolEncoder.java
@@ -20,7 +20,6 @@ import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.Context;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -28,6 +27,7 @@ import java.nio.charset.StandardCharsets;
 public class CastelProtocolEncoder extends BaseProtocolEncoder {
 
     private ByteBuf encodeContent(long deviceId, short type, ByteBuf content) {
+
         ByteBuf buf = Unpooled.buffer(0);
         String uniqueId = Context.getIdentityManager().getById(deviceId).getUniqueId();
 
@@ -63,10 +63,8 @@ public class CastelProtocolEncoder extends BaseProtocolEncoder {
                 content.writeByte(0);
                 return encodeContent(command.getDeviceId(), CastelProtocolDecoder.MSG_CC_PETROL_CONTROL, content);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/CellocatorFrameDecoder.java b/src/org/traccar/protocol/CellocatorFrameDecoder.java
index 986dc75ec..9bf9601fe 100644
--- a/src/org/traccar/protocol/CellocatorFrameDecoder.java
+++ b/src/org/traccar/protocol/CellocatorFrameDecoder.java
@@ -18,11 +18,14 @@ package org.traccar.protocol;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.BaseFrameDecoder;
-import org.traccar.helper.Log;
 
 public class CellocatorFrameDecoder extends BaseFrameDecoder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(CellocatorFrameDecoder.class);
+
     private static final int MESSAGE_MINIMUM_LENGTH = 15;
 
     @Override
@@ -54,7 +57,6 @@ public class CellocatorFrameDecoder extends BaseFrameDecoder {
                 length = 15 + buf.getUnsignedByte(13);
                 break;
             default:
-                Log.warning(new UnsupportedOperationException(String.valueOf(type)));
                 break;
         }
 
diff --git a/src/org/traccar/protocol/CellocatorProtocolEncoder.java b/src/org/traccar/protocol/CellocatorProtocolEncoder.java
index 4eef42128..0382dbbc7 100644
--- a/src/org/traccar/protocol/CellocatorProtocolEncoder.java
+++ b/src/org/traccar/protocol/CellocatorProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class CellocatorProtocolEncoder extends BaseProtocolEncoder {
@@ -60,11 +59,8 @@ public class CellocatorProtocolEncoder extends BaseProtocolEncoder {
                         + command.getInteger(Command.KEY_INDEX);
                 return encodeContent(command.getDeviceId(), 0x03, data, 0);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/CityeasyProtocolEncoder.java b/src/org/traccar/protocol/CityeasyProtocolEncoder.java
index e143563f0..350fdf0ab 100644
--- a/src/org/traccar/protocol/CityeasyProtocolEncoder.java
+++ b/src/org/traccar/protocol/CityeasyProtocolEncoder.java
@@ -21,7 +21,6 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class CityeasyProtocolEncoder extends BaseProtocolEncoder {
@@ -67,11 +66,8 @@ public class CityeasyProtocolEncoder extends BaseProtocolEncoder {
                 content.writeShort(Math.abs(timezone));
                 return encodeContent(CityeasyProtocolDecoder.MSG_TIMEZONE, content);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/EelinkProtocolEncoder.java b/src/org/traccar/protocol/EelinkProtocolEncoder.java
index 64236ca4a..c3ff88e1e 100644
--- a/src/org/traccar/protocol/EelinkProtocolEncoder.java
+++ b/src/org/traccar/protocol/EelinkProtocolEncoder.java
@@ -17,9 +17,10 @@ package org.traccar.protocol;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.DataConverter;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.ByteBuffer;
@@ -27,6 +28,8 @@ import java.nio.charset.StandardCharsets;
 
 public class EelinkProtocolEncoder extends BaseProtocolEncoder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(EelinkProtocolEncoder.class);
+
     private boolean connectionless;
 
     public EelinkProtocolEncoder(boolean connectionless) {
@@ -100,11 +103,8 @@ public class EelinkProtocolEncoder extends BaseProtocolEncoder {
             case Command.TYPE_REBOOT_DEVICE:
                 return encodeContent(command.getDeviceId(), "RESET#");
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/EnforaProtocolEncoder.java b/src/org/traccar/protocol/EnforaProtocolEncoder.java
index a8fe53691..a46e6367d 100644
--- a/src/org/traccar/protocol/EnforaProtocolEncoder.java
+++ b/src/org/traccar/protocol/EnforaProtocolEncoder.java
@@ -19,7 +19,6 @@ package org.traccar.protocol;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -49,11 +48,8 @@ public class EnforaProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_ENGINE_RESUME:
                 return encodeContent("AT$IOGP3=0");
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/EsealProtocolEncoder.java b/src/org/traccar/protocol/EsealProtocolEncoder.java
index 886bb80b1..b9bcc5b0a 100644
--- a/src/org/traccar/protocol/EsealProtocolEncoder.java
+++ b/src/org/traccar/protocol/EsealProtocolEncoder.java
@@ -16,7 +16,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class EsealProtocolEncoder extends StringProtocolEncoder {
@@ -35,11 +34,8 @@ public class EsealProtocolEncoder extends StringProtocolEncoder {
                 return formatCommand(
                         command, "##S,eSeal,{%s},256,3.0.8,RC-Unlock,E##", Command.KEY_UNIQUE_ID);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/GalileoProtocolEncoder.java b/src/org/traccar/protocol/GalileoProtocolEncoder.java
index 12463dc7d..3b2145e74 100644
--- a/src/org/traccar/protocol/GalileoProtocolEncoder.java
+++ b/src/org/traccar/protocol/GalileoProtocolEncoder.java
@@ -19,7 +19,6 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -61,11 +60,8 @@ public class GalileoProtocolEncoder extends BaseProtocolEncoder {
                 return encodeText(getUniqueId(command.getDeviceId()),
                         "Out " + command.getInteger(Command.KEY_INDEX) + "," + command.getString(Command.KEY_DATA));
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/Gl200ProtocolEncoder.java b/src/org/traccar/protocol/Gl200ProtocolEncoder.java
index 2c8efa318..285106c67 100644
--- a/src/org/traccar/protocol/Gl200ProtocolEncoder.java
+++ b/src/org/traccar/protocol/Gl200ProtocolEncoder.java
@@ -16,7 +16,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class Gl200ProtocolEncoder extends StringProtocolEncoder {
@@ -40,11 +39,8 @@ public class Gl200ProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_REBOOT_DEVICE:
                 return formatCommand(command, "AT+GTRTO={%s},3,,,,,,FFFF$", Command.KEY_DEVICE_PASSWORD);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/Gps103ProtocolEncoder.java b/src/org/traccar/protocol/Gps103ProtocolEncoder.java
index 36801b401..47ef2f333 100644
--- a/src/org/traccar/protocol/Gps103ProtocolEncoder.java
+++ b/src/org/traccar/protocol/Gps103ProtocolEncoder.java
@@ -16,7 +16,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class Gps103ProtocolEncoder extends StringProtocolEncoder implements StringProtocolEncoder.ValueFormatter {
@@ -62,11 +61,8 @@ public class Gps103ProtocolEncoder extends StringProtocolEncoder implements Stri
             case Command.TYPE_REQUEST_PHOTO:
                 return formatCommand(command, "**,imei:{%s},160", Command.KEY_UNIQUE_ID);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/GranitProtocolEncoder.java b/src/org/traccar/protocol/GranitProtocolEncoder.java
index bde267ee6..6345ff971 100644
--- a/src/org/traccar/protocol/GranitProtocolEncoder.java
+++ b/src/org/traccar/protocol/GranitProtocolEncoder.java
@@ -20,36 +20,29 @@ import java.nio.charset.StandardCharsets;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class GranitProtocolEncoder extends BaseProtocolEncoder {
-    @Override
-    protected Object encodeCommand(Command command) {
 
-        String commandString = "";
+    private ByteBuf encodeCommand(String commandString) {
+        ByteBuf buffer = Unpooled.buffer();
+        buffer.writeBytes(commandString.getBytes(StandardCharsets.US_ASCII));
+        GranitProtocolDecoder.appendChecksum(buffer, commandString.length());
+        return buffer;
+    }
 
+    @Override
+    protected Object encodeCommand(Command command) {
         switch (command.getType()) {
             case Command.TYPE_IDENTIFICATION:
-                commandString = "BB+IDNT";
-                break;
+                return encodeCommand("BB+IDNT");
             case Command.TYPE_REBOOT_DEVICE:
-                commandString = "BB+RESET";
-                break;
+                return encodeCommand("BB+RESET");
             case Command.TYPE_POSITION_SINGLE:
-                commandString = "BB+RRCD";
-                break;
+                return encodeCommand("BB+RRCD");
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
                 return null;
         }
-        if (!commandString.isEmpty()) {
-            ByteBuf commandBuf = Unpooled.buffer();
-            commandBuf.writeBytes(commandString.getBytes(StandardCharsets.US_ASCII));
-            GranitProtocolDecoder.appendChecksum(commandBuf, commandString.length());
-            return commandBuf;
-        }
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/GranitProtocolSmsEncoder.java b/src/org/traccar/protocol/GranitProtocolSmsEncoder.java
index 668e5d4d3..7d5518c17 100644
--- a/src/org/traccar/protocol/GranitProtocolSmsEncoder.java
+++ b/src/org/traccar/protocol/GranitProtocolSmsEncoder.java
@@ -17,7 +17,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class GranitProtocolSmsEncoder extends StringProtocolEncoder {
@@ -30,7 +29,6 @@ public class GranitProtocolSmsEncoder extends StringProtocolEncoder {
         case Command.TYPE_POSITION_PERIODIC:
             return formatCommand(command, "BB+BBMD={%s}", Command.KEY_FREQUENCY);
         default:
-            Log.warning(new UnsupportedOperationException(command.getType()));
             return null;
         }
     }
diff --git a/src/org/traccar/protocol/Gt06ProtocolEncoder.java b/src/org/traccar/protocol/Gt06ProtocolEncoder.java
index 46b4fa5a4..05560229f 100644
--- a/src/org/traccar/protocol/Gt06ProtocolEncoder.java
+++ b/src/org/traccar/protocol/Gt06ProtocolEncoder.java
@@ -20,7 +20,6 @@ import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.Context;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -72,11 +71,8 @@ public class Gt06ProtocolEncoder extends BaseProtocolEncoder {
             case Command.TYPE_CUSTOM:
                 return encodeContent(command.getDeviceId(), command.getString(Command.KEY_DATA));
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/H02ProtocolEncoder.java b/src/org/traccar/protocol/H02ProtocolEncoder.java
index fb418dbab..87fad6016 100644
--- a/src/org/traccar/protocol/H02ProtocolEncoder.java
+++ b/src/org/traccar/protocol/H02ProtocolEncoder.java
@@ -19,7 +19,6 @@ package org.traccar.protocol;
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class H02ProtocolEncoder extends StringProtocolEncoder {
@@ -57,11 +56,8 @@ public class H02ProtocolEncoder extends StringProtocolEncoder {
                 return formatCommand(
                         time, uniqueId, "S71", "22", command.getAttributes().get(Command.KEY_FREQUENCY).toString());
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
     @Override
diff --git a/src/org/traccar/protocol/HuabaoProtocolEncoder.java b/src/org/traccar/protocol/HuabaoProtocolEncoder.java
index a2702fec7..056597b50 100644
--- a/src/org/traccar/protocol/HuabaoProtocolEncoder.java
+++ b/src/org/traccar/protocol/HuabaoProtocolEncoder.java
@@ -19,7 +19,6 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.DataConverter;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.text.SimpleDateFormat;
@@ -46,7 +45,6 @@ public class HuabaoProtocolEncoder extends BaseProtocolEncoder {
                     data.writeBytes(time);
                     return HuabaoProtocolDecoder.formatMessage(HuabaoProtocolDecoder.MSG_OIL_CONTROL, id, data);
                 default:
-                    Log.warning(new UnsupportedOperationException(command.getType()));
                     return null;
             }
         } finally {
diff --git a/src/org/traccar/protocol/Jt600ProtocolEncoder.java b/src/org/traccar/protocol/Jt600ProtocolEncoder.java
index 1d868cbcf..fe5c63c32 100644
--- a/src/org/traccar/protocol/Jt600ProtocolEncoder.java
+++ b/src/org/traccar/protocol/Jt600ProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 import java.util.TimeZone;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class Jt600ProtocolEncoder extends StringProtocolEncoder {
@@ -37,11 +36,8 @@ public class Jt600ProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_REBOOT_DEVICE:
                 return "(S17)";
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/KhdProtocolEncoder.java b/src/org/traccar/protocol/KhdProtocolEncoder.java
index 9c0f0b67a..c66129283 100644
--- a/src/org/traccar/protocol/KhdProtocolEncoder.java
+++ b/src/org/traccar/protocol/KhdProtocolEncoder.java
@@ -19,7 +19,6 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class KhdProtocolEncoder extends BaseProtocolEncoder {
@@ -61,11 +60,8 @@ public class KhdProtocolEncoder extends BaseProtocolEncoder {
             case Command.TYPE_ENGINE_RESUME:
                 return encodeCommand(MSG_RESUME_OIL, uniqueId);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/MeiligaoProtocolEncoder.java b/src/org/traccar/protocol/MeiligaoProtocolEncoder.java
index 6052b2617..57cbbe0fc 100644
--- a/src/org/traccar/protocol/MeiligaoProtocolEncoder.java
+++ b/src/org/traccar/protocol/MeiligaoProtocolEncoder.java
@@ -20,7 +20,6 @@ import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.Checksum;
 import org.traccar.helper.DataConverter;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -80,11 +79,8 @@ public class MeiligaoProtocolEncoder extends BaseProtocolEncoder {
             case Command.TYPE_REBOOT_DEVICE:
                 return encodeContent(command.getDeviceId(), MeiligaoProtocolDecoder.MSG_REBOOT_GPS, content);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/MeitrackProtocolEncoder.java b/src/org/traccar/protocol/MeitrackProtocolEncoder.java
index af059508b..abb6ec9d4 100644
--- a/src/org/traccar/protocol/MeitrackProtocolEncoder.java
+++ b/src/org/traccar/protocol/MeitrackProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 import org.traccar.Context;
 import org.traccar.StringProtocolEncoder;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.util.Map;
@@ -59,11 +58,8 @@ public class MeitrackProtocolEncoder extends StringProtocolEncoder {
                 return formatCommand(command, 'f', "C02,0,"
                         + attributes.get(Command.KEY_PHONE) + "," + attributes.get(Command.KEY_MESSAGE));
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/MiniFinderProtocolEncoder.java b/src/org/traccar/protocol/MiniFinderProtocolEncoder.java
index d3f49b4e4..7a3d5b226 100644
--- a/src/org/traccar/protocol/MiniFinderProtocolEncoder.java
+++ b/src/org/traccar/protocol/MiniFinderProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 import java.util.TimeZone;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class MiniFinderProtocolEncoder extends StringProtocolEncoder implements StringProtocolEncoder.ValueFormatter {
@@ -76,7 +75,6 @@ public class MiniFinderProtocolEncoder extends StringProtocolEncoder implements
             case Command.TYPE_SET_INDICATOR:
                 return formatCommand(command, "{%s}LED{%s}", Command.KEY_DEVICE_PASSWORD, Command.KEY_DATA);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
                 return null;
         }
     }
diff --git a/src/org/traccar/protocol/Mta6ProtocolDecoder.java b/src/org/traccar/protocol/Mta6ProtocolDecoder.java
index 94b624612..ec20658c7 100644
--- a/src/org/traccar/protocol/Mta6ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Mta6ProtocolDecoder.java
@@ -23,13 +23,14 @@ import io.netty.handler.codec.http.FullHttpRequest;
 import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.HttpResponseStatus;
 import io.netty.handler.codec.http.HttpVersion;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
 import org.traccar.NetworkMessage;
 import org.traccar.Protocol;
 import org.traccar.helper.BitUtil;
 import org.traccar.helper.DateBuilder;
-import org.traccar.helper.Log;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Position;
 
@@ -41,6 +42,8 @@ import java.util.List;
 
 public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(Mta6ProtocolDecoder.class);
+
     private final boolean simple;
 
     public Mta6ProtocolDecoder(Protocol protocol, boolean simple) {
@@ -85,7 +88,7 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
                     previousFloat = (previousFloat & 0xff000000) + ((buf.readUnsignedMedium() & 0x3fffff) << 2);
                     break;
                 default:
-                    Log.warning(new IllegalArgumentException());
+                    LOGGER.warn(null, new IllegalArgumentException());
                     break;
             }
             return Float.intBitsToFloat(previousFloat);
@@ -192,7 +195,7 @@ public class Mta6ProtocolDecoder extends BaseProtocolDecoder {
                 positions.add(position);
             }
         } catch (IndexOutOfBoundsException error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
 
         return positions;
diff --git a/src/org/traccar/protocol/NavigilProtocolDecoder.java b/src/org/traccar/protocol/NavigilProtocolDecoder.java
index 19eb37c27..c330907f7 100644
--- a/src/org/traccar/protocol/NavigilProtocolDecoder.java
+++ b/src/org/traccar/protocol/NavigilProtocolDecoder.java
@@ -22,7 +22,6 @@ import org.traccar.BaseProtocolDecoder;
 import org.traccar.DeviceSession;
 import org.traccar.NetworkMessage;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.helper.UnitsConverter;
 import org.traccar.model.Position;
 
@@ -301,11 +300,8 @@ public class NavigilProtocolDecoder extends BaseProtocolDecoder {
             case MSG_TRACKING_DATA:
                 return parseTrackingData(deviceSession, buf, sequenceNumber, timestamp);
             default:
-                Log.warning(new UnsupportedOperationException(String.valueOf(messageId)));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/NoranProtocolEncoder.java b/src/org/traccar/protocol/NoranProtocolEncoder.java
index 53b0c54ba..92826c8b2 100644
--- a/src/org/traccar/protocol/NoranProtocolEncoder.java
+++ b/src/org/traccar/protocol/NoranProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -58,11 +57,8 @@ public class NoranProtocolEncoder extends BaseProtocolEncoder {
             case Command.TYPE_ENGINE_RESUME:
                 return encodeContent("*KW,000,007,000000,1#");
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/PretraceProtocolEncoder.java b/src/org/traccar/protocol/PretraceProtocolEncoder.java
index e8e2f66c7..9cf951e3b 100644
--- a/src/org/traccar/protocol/PretraceProtocolEncoder.java
+++ b/src/org/traccar/protocol/PretraceProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.Context;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class PretraceProtocolEncoder extends BaseProtocolEncoder {
@@ -40,7 +39,6 @@ public class PretraceProtocolEncoder extends BaseProtocolEncoder {
                 return formatCommand(
                         uniqueId, String.format("D221%1$d,%1$d,,", command.getInteger(Command.KEY_FREQUENCY)));
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
                 return null;
         }
     }
diff --git a/src/org/traccar/protocol/Pt502ProtocolEncoder.java b/src/org/traccar/protocol/Pt502ProtocolEncoder.java
index bd56e306a..ed18208cc 100644
--- a/src/org/traccar/protocol/Pt502ProtocolEncoder.java
+++ b/src/org/traccar/protocol/Pt502ProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 import java.util.TimeZone;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class Pt502ProtocolEncoder extends StringProtocolEncoder implements StringProtocolEncoder.ValueFormatter {
@@ -52,11 +51,8 @@ public class Pt502ProtocolEncoder extends StringProtocolEncoder implements Strin
             case Command.TYPE_REQUEST_PHOTO:
                 return formatCommand(command, "#PHO\r\n");
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/RuptelaProtocolEncoder.java b/src/org/traccar/protocol/RuptelaProtocolEncoder.java
index 28aa65273..4242584c9 100644
--- a/src/org/traccar/protocol/RuptelaProtocolEncoder.java
+++ b/src/org/traccar/protocol/RuptelaProtocolEncoder.java
@@ -19,7 +19,6 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -67,11 +66,8 @@ public class RuptelaProtocolEncoder extends BaseProtocolEncoder {
                 content.writeInt(Integer.parseInt(command.getString(Command.KEY_DATA)));
                 return encodeContent(RuptelaProtocolDecoder.MSG_SET_ODOMETER, content);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/SkypatrolProtocolDecoder.java b/src/org/traccar/protocol/SkypatrolProtocolDecoder.java
index 054171914..826311052 100644
--- a/src/org/traccar/protocol/SkypatrolProtocolDecoder.java
+++ b/src/org/traccar/protocol/SkypatrolProtocolDecoder.java
@@ -17,12 +17,13 @@ package org.traccar.protocol;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.Channel;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.Context;
 import org.traccar.DeviceSession;
 import org.traccar.helper.BitUtil;
 import org.traccar.helper.DateBuilder;
-import org.traccar.helper.Log;
 import org.traccar.model.Position;
 
 import java.net.SocketAddress;
@@ -30,6 +31,8 @@ import java.nio.charset.StandardCharsets;
 
 public class SkypatrolProtocolDecoder extends BaseProtocolDecoder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(SkypatrolProtocolDecoder.class);
+
     private final long defaultMask;
 
     public SkypatrolProtocolDecoder(SkypatrolProtocol protocol) {
@@ -81,7 +84,7 @@ public class SkypatrolProtocolDecoder extends BaseProtocolDecoder {
                 id = buf.toString(buf.readerIndex(), 22, StandardCharsets.US_ASCII).trim();
                 buf.skipBytes(22);
             } else {
-                Log.warning("No device id field");
+                LOGGER.warn("No device id field");
                 return null;
             }
             DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, id);
diff --git a/src/org/traccar/protocol/SuntechProtocolEncoder.java b/src/org/traccar/protocol/SuntechProtocolEncoder.java
index 5b1c802fa..90fa4aa39 100644
--- a/src/org/traccar/protocol/SuntechProtocolEncoder.java
+++ b/src/org/traccar/protocol/SuntechProtocolEncoder.java
@@ -16,7 +16,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class SuntechProtocolEncoder extends StringProtocolEncoder {
@@ -48,11 +47,8 @@ public class SuntechProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_ALARM_DISARM:
                 return formatCommand(command, "SA200CMD;{%s};02;Disable2\r", Command.KEY_UNIQUE_ID);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/SviasProtocolEncoder.java b/src/org/traccar/protocol/SviasProtocolEncoder.java
index c26ee2032..9fce57223 100644
--- a/src/org/traccar/protocol/SviasProtocolEncoder.java
+++ b/src/org/traccar/protocol/SviasProtocolEncoder.java
@@ -17,7 +17,6 @@
 package org.traccar.protocol;

 

 import org.traccar.StringProtocolEncoder;

-import org.traccar.helper.Log;

 import org.traccar.model.Command;

 

 public class SviasProtocolEncoder extends StringProtocolEncoder {

@@ -42,10 +41,8 @@ public class SviasProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_ALARM_REMOVE:

                 return formatCommand(command, "AT+PNC=600*");

             default:

-                Log.warning(new UnsupportedOperationException(command.getType()));

-                break;

+                return null;

         }

-        return null;

     }

 

 }

diff --git a/src/org/traccar/protocol/T800xProtocolEncoder.java b/src/org/traccar/protocol/T800xProtocolEncoder.java
index ba17c9d75..1d0f3dabe 100644
--- a/src/org/traccar/protocol/T800xProtocolEncoder.java
+++ b/src/org/traccar/protocol/T800xProtocolEncoder.java
@@ -19,7 +19,6 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.DataConverter;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -53,11 +52,8 @@ public class T800xProtocolEncoder extends BaseProtocolEncoder {
             case Command.TYPE_CUSTOM:
                 return encodeContent(command, command.getString(Command.KEY_DATA));
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/TeltonikaProtocolEncoder.java b/src/org/traccar/protocol/TeltonikaProtocolEncoder.java
index f2680c27c..944cec024 100644
--- a/src/org/traccar/protocol/TeltonikaProtocolEncoder.java
+++ b/src/org/traccar/protocol/TeltonikaProtocolEncoder.java
@@ -17,7 +17,6 @@ package org.traccar.protocol;
 
 import org.traccar.BaseProtocolEncoder;
 import org.traccar.helper.Checksum;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import io.netty.buffer.ByteBuf;
@@ -53,11 +52,8 @@ public class TeltonikaProtocolEncoder extends BaseProtocolEncoder {
             case Command.TYPE_CUSTOM:
                 return encodeContent(command.getString(Command.KEY_DATA));
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/Tk103ProtocolEncoder.java b/src/org/traccar/protocol/Tk103ProtocolEncoder.java
index d64c85c2c..d4544707a 100644
--- a/src/org/traccar/protocol/Tk103ProtocolEncoder.java
+++ b/src/org/traccar/protocol/Tk103ProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 
 import org.traccar.Context;
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class Tk103ProtocolEncoder extends StringProtocolEncoder {
@@ -75,7 +74,6 @@ public class Tk103ProtocolEncoder extends StringProtocolEncoder {
                 case Command.TYPE_SOS_NUMBER:
                     return formatAlt(command, "*master*{%s}*{%s}*", Command.KEY_DEVICE_PASSWORD, Command.KEY_PHONE);
                 default:
-                    Log.warning(new UnsupportedOperationException(command.getType()));
                     return null;
             }
         } else {
@@ -102,7 +100,6 @@ public class Tk103ProtocolEncoder extends StringProtocolEncoder {
                 case Command.TYPE_OUTPUT_CONTROL:
                     return formatCommand(command, "({%s}AV00{%s})", Command.KEY_UNIQUE_ID, Command.KEY_DATA);
                 default:
-                    Log.warning(new UnsupportedOperationException(command.getType()));
                     return null;
             }
         }
diff --git a/src/org/traccar/protocol/TotemProtocolEncoder.java b/src/org/traccar/protocol/TotemProtocolEncoder.java
index ff41a7df3..b5049859d 100644
--- a/src/org/traccar/protocol/TotemProtocolEncoder.java
+++ b/src/org/traccar/protocol/TotemProtocolEncoder.java
@@ -17,7 +17,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class TotemProtocolEncoder extends StringProtocolEncoder {
@@ -34,11 +33,8 @@ public class TotemProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_ENGINE_RESUME:
                 return formatCommand(command, "*{%s},025,C,0#", Command.KEY_DEVICE_PASSWORD);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/WatchProtocolEncoder.java b/src/org/traccar/protocol/WatchProtocolEncoder.java
index b2d35e702..482f2f0bf 100644
--- a/src/org/traccar/protocol/WatchProtocolEncoder.java
+++ b/src/org/traccar/protocol/WatchProtocolEncoder.java
@@ -18,7 +18,6 @@ package org.traccar.protocol;
 import io.netty.channel.Channel;
 import org.traccar.StringProtocolEncoder;
 import org.traccar.helper.DataConverter;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 import java.nio.charset.StandardCharsets;
@@ -144,11 +143,8 @@ public class WatchProtocolEncoder extends StringProtocolEncoder implements Strin
             case Command.TYPE_SET_INDICATOR:
                 return formatCommand(channel, command, "FLOWER,{%s}", Command.KEY_DATA);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/WialonProtocolEncoder.java b/src/org/traccar/protocol/WialonProtocolEncoder.java
index 9c60a1356..9ff1631eb 100644
--- a/src/org/traccar/protocol/WialonProtocolEncoder.java
+++ b/src/org/traccar/protocol/WialonProtocolEncoder.java
@@ -17,7 +17,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class WialonProtocolEncoder extends StringProtocolEncoder {
@@ -34,9 +33,8 @@ public class WialonProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_OUTPUT_CONTROL:
                 return formatCommand(command, "L{%s}={%s}\r\n", Command.KEY_INDEX, Command.KEY_DATA);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-        return null;
     }
+
 }
diff --git a/src/org/traccar/protocol/WondexProtocolEncoder.java b/src/org/traccar/protocol/WondexProtocolEncoder.java
index 6258c1fe6..f9e8eeb9b 100644
--- a/src/org/traccar/protocol/WondexProtocolEncoder.java
+++ b/src/org/traccar/protocol/WondexProtocolEncoder.java
@@ -16,10 +16,10 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class WondexProtocolEncoder extends StringProtocolEncoder {
+
     @Override
     protected Object encodeCommand(Command command) {
 
@@ -39,11 +39,8 @@ public class WondexProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_GET_VERSION:
                 return formatCommand(command, "$WP+VER={%s}", Command.KEY_DEVICE_PASSWORD);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/XexunProtocolEncoder.java b/src/org/traccar/protocol/XexunProtocolEncoder.java
index cdf3ac6f7..515cfbbd0 100644
--- a/src/org/traccar/protocol/XexunProtocolEncoder.java
+++ b/src/org/traccar/protocol/XexunProtocolEncoder.java
@@ -16,7 +16,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class XexunProtocolEncoder extends StringProtocolEncoder {
@@ -32,11 +31,8 @@ public class XexunProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_ENGINE_RESUME:
                 return formatCommand(command, "powercar{%s} 00", Command.KEY_DEVICE_PASSWORD);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/protocol/XirgoProtocolEncoder.java b/src/org/traccar/protocol/XirgoProtocolEncoder.java
index fde531831..dd5e30cca 100644
--- a/src/org/traccar/protocol/XirgoProtocolEncoder.java
+++ b/src/org/traccar/protocol/XirgoProtocolEncoder.java
@@ -16,7 +16,6 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
-import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class XirgoProtocolEncoder extends StringProtocolEncoder {
@@ -28,11 +27,8 @@ public class XirgoProtocolEncoder extends StringProtocolEncoder {
             case Command.TYPE_OUTPUT_CONTROL:
                 return String.format("+XT:7005,%d,1", command.getInteger(Command.KEY_DATA) + 1);
             default:
-                Log.warning(new UnsupportedOperationException(command.getType()));
-                break;
+                return null;
         }
-
-        return null;
     }
 
 }
diff --git a/src/org/traccar/smpp/ClientSmppSessionHandler.java b/src/org/traccar/smpp/ClientSmppSessionHandler.java
index 3585f8376..37882c76a 100644
--- a/src/org/traccar/smpp/ClientSmppSessionHandler.java
+++ b/src/org/traccar/smpp/ClientSmppSessionHandler.java
@@ -16,8 +16,9 @@
  */
 package org.traccar.smpp;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.events.TextMessageEventHandler;
-import org.traccar.helper.Log;
 
 import com.cloudhopper.commons.charset.CharsetUtil;
 import com.cloudhopper.smpp.SmppConstants;
@@ -29,6 +30,8 @@ import com.cloudhopper.smpp.util.SmppUtil;
 
 public class ClientSmppSessionHandler extends DefaultSmppSessionHandler {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(ClientSmppSessionHandler.class);
+
     private SmppClient smppClient;
 
     public ClientSmppSessionHandler(SmppClient smppClient) {
@@ -37,7 +40,7 @@ public class ClientSmppSessionHandler extends DefaultSmppSessionHandler {
 
     @Override
     public void firePduRequestExpired(PduRequest pduRequest) {
-        Log.warning("PDU request expired: " + pduRequest);
+        LOGGER.warn("PDU request expired: " + pduRequest);
     }
 
     @Override
@@ -48,7 +51,7 @@ public class ClientSmppSessionHandler extends DefaultSmppSessionHandler {
                 String sourceAddress = ((DeliverSm) request).getSourceAddress().getAddress();
                 String message = CharsetUtil.decode(((DeliverSm) request).getShortMessage(),
                         smppClient.mapDataCodingToCharset(((DeliverSm) request).getDataCoding()));
-                Log.debug("SMS Message Received: " + message.trim() + ", Source Address: " + sourceAddress);
+                LOGGER.debug("SMS Message Received: " + message.trim() + ", Source Address: " + sourceAddress);
 
                 boolean isDeliveryReceipt = false;
                 if (smppClient.getDetectDlrByOpts()) {
@@ -63,7 +66,7 @@ public class ClientSmppSessionHandler extends DefaultSmppSessionHandler {
             }
             response = request.createResponse();
         } catch (Throwable error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
             response = request.createResponse();
             response.setResultMessage(error.getMessage());
             response.setCommandStatus(SmppConstants.STATUS_UNKNOWNERR);
@@ -73,7 +76,7 @@ public class ClientSmppSessionHandler extends DefaultSmppSessionHandler {
 
     @Override
     public void fireChannelUnexpectedlyClosed() {
-        Log.warning("SMPP session channel unexpectedly closed");
+        LOGGER.warn("SMPP session channel unexpectedly closed");
         smppClient.scheduleReconnect();
     }
 }
diff --git a/src/org/traccar/smpp/EnquireLinkTask.java b/src/org/traccar/smpp/EnquireLinkTask.java
index affb712b3..3072f975a 100644
--- a/src/org/traccar/smpp/EnquireLinkTask.java
+++ b/src/org/traccar/smpp/EnquireLinkTask.java
@@ -16,7 +16,8 @@
  */
 package org.traccar.smpp;
 
-import org.traccar.helper.Log;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import com.cloudhopper.smpp.SmppSession;
 import com.cloudhopper.smpp.pdu.EnquireLink;
@@ -27,6 +28,8 @@ import com.cloudhopper.smpp.type.UnrecoverablePduException;
 
 public class EnquireLinkTask implements Runnable {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(EnquireLinkTask.class);
+
     private SmppClient smppClient;
     private Integer enquireLinkTimeout;
 
@@ -43,13 +46,13 @@ public class EnquireLinkTask implements Runnable {
                 smppSession.enquireLink(new EnquireLink(), enquireLinkTimeout);
             } catch (SmppTimeoutException | SmppChannelException
                     | RecoverablePduException | UnrecoverablePduException error) {
-                Log.warning("Enquire link failed, executing reconnect: ", error);
+                LOGGER.warn("Enquire link failed, executing reconnect: ", error);
                 smppClient.scheduleReconnect();
             } catch (InterruptedException error) {
-                Log.info("Enquire link interrupted, probably killed by reconnecting");
+                LOGGER.info("Enquire link interrupted, probably killed by reconnecting");
             }
         } else {
-            Log.warning("Enquire link running while session is not connected");
+            LOGGER.warn("Enquire link running while session is not connected");
         }
     }
 
diff --git a/src/org/traccar/smpp/SmppClient.java b/src/org/traccar/smpp/SmppClient.java
index ddda4cb4f..d7e262c87 100644
--- a/src/org/traccar/smpp/SmppClient.java
+++ b/src/org/traccar/smpp/SmppClient.java
@@ -23,8 +23,9 @@ import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.notification.MessageException;
 import org.traccar.sms.SmsManager;
 
@@ -46,6 +47,8 @@ import com.cloudhopper.smpp.type.UnrecoverablePduException;
 
 public class SmppClient implements SmsManager {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(SmppClient.class);
+
     private SmppSessionConfiguration sessionConfig = new SmppSessionConfiguration();
     private SmppSession smppSession;
     private DefaultSmppSessionHandler sessionHandler = new ClientSmppSessionHandler(this);
@@ -168,10 +171,10 @@ public class SmppClient implements SmsManager {
             smppSession = clientBootstrap.bind(sessionConfig, sessionHandler);
             stopReconnectionkTask();
             runEnquireLinkTask();
-            Log.info("SMPP session connected");
+            LOGGER.info("SMPP session connected");
         } catch (SmppTimeoutException | SmppChannelException
                 | UnrecoverablePduException | InterruptedException error) {
-            Log.warning("Unable to connect to SMPP server: ", error);
+            LOGGER.warn("Unable to connect to SMPP server: ", error);
         }
     }
 
@@ -208,7 +211,7 @@ public class SmppClient implements SmsManager {
 
     private void destroySession() {
         if (smppSession != null) {
-            Log.debug("Cleaning up SMPP session... ");
+            LOGGER.debug("Cleaning up SMPP session... ");
             smppSession.destroy();
             smppSession = null;
         }
@@ -239,7 +242,7 @@ public class SmppClient implements SmsManager {
                 submit.setDestAddress(new Address(destTon, destNpi, destAddress));
                 SubmitSmResp submitResponce = getSession().submit(submit, submitTimeout);
                 if (submitResponce.getCommandStatus() == SmppConstants.STATUS_OK) {
-                    Log.debug("SMS submitted, message id: " + submitResponce.getMessageId());
+                    LOGGER.debug("SMS submitted, message id: " + submitResponce.getMessageId());
                 } else {
                     throw new IllegalStateException(submitResponce.getResultMessage());
                 }
@@ -260,7 +263,7 @@ public class SmppClient implements SmsManager {
                 try {
                     sendMessageSync(destAddress, message, command);
                 } catch (MessageException | InterruptedException | IllegalStateException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         });
diff --git a/src/org/traccar/web/ConsoleServlet.java b/src/org/traccar/web/ConsoleServlet.java
index 9b3d8d54b..dddd13b6d 100644
--- a/src/org/traccar/web/ConsoleServlet.java
+++ b/src/org/traccar/web/ConsoleServlet.java
@@ -17,8 +17,9 @@ package org.traccar.web;
 
 import org.h2.server.web.ConnectionInfo;
 import org.h2.server.web.WebServlet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
@@ -26,6 +27,8 @@ import java.lang.reflect.Method;
 
 public class ConsoleServlet extends WebServlet {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(ConsoleServlet.class);
+
     @Override
     public void init() {
         super.init();
@@ -51,7 +54,7 @@ public class ConsoleServlet extends WebServlet {
             method.invoke(server, true);
 
         } catch (NoSuchFieldException | IllegalAccessException | NoSuchMethodException | InvocationTargetException e) {
-            Log.warning(e);
+            LOGGER.warn(null, e);
         }
     }
 
diff --git a/src/org/traccar/web/CsvBuilder.java b/src/org/traccar/web/CsvBuilder.java
index fa99f1b18..d5149b528 100644
--- a/src/org/traccar/web/CsvBuilder.java
+++ b/src/org/traccar/web/CsvBuilder.java
@@ -31,11 +31,14 @@ import com.fasterxml.jackson.core.JsonProcessingException;
 import org.joda.time.DateTime;
 import org.joda.time.format.DateTimeFormatter;
 import org.joda.time.format.ISODateTimeFormat;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Context;
-import org.traccar.helper.Log;
 
 public class CsvBuilder {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(CsvBuilder.class);
+
     private static final String LINE_ENDING = "\r\n";
     private static final String SEPARATOR = ";";
     private static final DateTimeFormatter DATE_FORMAT = ISODateTimeFormat.dateTime();
@@ -103,12 +106,12 @@ public class CsvBuilder {
                                 builder.append(map);
                                 addSeparator();
                             } catch (JsonProcessingException e) {
-                                Log.warning(e);
+                                LOGGER.warn(null, e);
                             }
                         }
                     }
                 } catch (IllegalAccessException | InvocationTargetException error) {
-                    Log.warning(error);
+                    LOGGER.warn(null, error);
                 }
             }
         }
diff --git a/src/org/traccar/web/WebServer.java b/src/org/traccar/web/WebServer.java
index 13eebf34f..32c336164 100644
--- a/src/org/traccar/web/WebServer.java
+++ b/src/org/traccar/web/WebServer.java
@@ -32,6 +32,8 @@ import org.eclipse.jetty.webapp.WebAppContext;
 import org.glassfish.jersey.jackson.JacksonFeature;
 import org.glassfish.jersey.server.ResourceConfig;
 import org.glassfish.jersey.servlet.ServletContainer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.traccar.Config;
 import org.traccar.Context;
 import org.traccar.api.AsyncSocketServlet;
@@ -41,7 +43,6 @@ import org.traccar.api.ObjectMapperProvider;
 import org.traccar.api.ResourceErrorHandler;
 import org.traccar.api.SecurityRequestFilter;
 import org.traccar.api.resource.ServerResource;
-import org.traccar.helper.Log;
 
 import javax.naming.InitialContext;
 import javax.servlet.DispatcherType;
@@ -56,6 +57,8 @@ import java.util.EnumSet;
 
 public class WebServer {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(WebServer.class);
+
     private Server server;
     private final Config config;
     private final DataSource dataSource;
@@ -150,7 +153,7 @@ public class WebServer {
             javax.naming.Context context = new InitialContext();
             context.bind("java:/DefaultDS", dataSource);
         } catch (Exception error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
 
         WebAppContext app = new WebAppContext();
@@ -196,7 +199,7 @@ public class WebServer {
         try {
             server.start();
         } catch (Exception error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
     }
 
@@ -204,7 +207,7 @@ public class WebServer {
         try {
             server.stop();
         } catch (Exception error) {
-            Log.warning(error);
+            LOGGER.warn(null, error);
         }
     }