Change Meitrack encoder implementation

3 files changed, 27 insertions, 8 deletions

diff --git a/src/org/traccar/helper/Checksum.java b/src/org/traccar/helper/Checksum.java
index e6b6cd2c8..c156e53f7 100644
--- a/src/org/traccar/helper/Checksum.java
+++ b/src/org/traccar/helper/Checksum.java
@@ -158,13 +158,20 @@ public final class Checksum {
 
     public static String nmea(String msg) {
         int checksum = 0;
-        byte[] bytes = msg.getBytes(Charset.defaultCharset());
-        for (int i = 1; i < msg.length(); i++) {
-            checksum ^= bytes[i];
+        for (byte b : msg.getBytes(Charset.defaultCharset())) {
+            checksum ^= b;
         }
         return String.format("*%02x", checksum).toUpperCase();
     }
 
+    public static String sum(String msg) {
+        byte checksum = 0;
+        for (byte b : msg.getBytes(Charset.defaultCharset())) {
+            checksum += b;
+        }
+        return String.format("%02X", checksum).toUpperCase();
+    }
+
     public static long luhn(long imei) {
         long checksum = 0;
         long remain = imei;
diff --git a/src/org/traccar/protocol/MeitrackProtocol.java b/src/org/traccar/protocol/MeitrackProtocol.java
index e758e5f41..e5b5ddf2b 100644
--- a/src/org/traccar/protocol/MeitrackProtocol.java
+++ b/src/org/traccar/protocol/MeitrackProtocol.java
@@ -31,6 +31,7 @@ public class MeitrackProtocol extends BaseProtocol {
     public MeitrackProtocol() {
         super("meitrack");
         setSupportedCommands(
+                Command.TYPE_POSITION_SINGLE,
                 Command.TYPE_ENGINE_STOP,
                 Command.TYPE_ENGINE_RESUME,
                 Command.TYPE_ALARM_ARM,
diff --git a/src/org/traccar/protocol/MeitrackProtocolEncoder.java b/src/org/traccar/protocol/MeitrackProtocolEncoder.java
index 90fa5b624..381935c58 100644
--- a/src/org/traccar/protocol/MeitrackProtocolEncoder.java
+++ b/src/org/traccar/protocol/MeitrackProtocolEncoder.java
@@ -16,25 +16,36 @@
 package org.traccar.protocol;
 
 import org.traccar.StringProtocolEncoder;
+import org.traccar.helper.Checksum;
 import org.traccar.helper.Log;
 import org.traccar.model.Command;
 
 public class MeitrackProtocolEncoder extends StringProtocolEncoder {
 
+    private Object formatCommand(Command command, char dataId, String content) {
+        String uniqueId = getUniqueId(command.getDeviceId());
+        int length = 1 + uniqueId.length() + 1 + content.length() + 5;
+        String result = String.format("@@%c%02d,%s,%s*", dataId, length, uniqueId, content);
+        result += Checksum.sum(result) + "\r\n";
+        return result;
+    }
+
     @Override
     protected Object encodeCommand(Command command) {
 
         switch (command.getType()) {
+            case Command.TYPE_POSITION_SINGLE:
+                return formatCommand(command, 'Q', "A10");
             case Command.TYPE_ENGINE_STOP:
-                return formatCommand(command, "@@M33,{%s},C01,0,12222*00\r\n", Command.KEY_UNIQUE_ID);
+                return formatCommand(command, 'M', "C01,0,12222");
             case Command.TYPE_ENGINE_RESUME:
-                return formatCommand(command, "@@M33,{%s},C01,0,02222*00\r\n", Command.KEY_UNIQUE_ID);
+                return formatCommand(command, 'M', "C01,0,02222");
             case Command.TYPE_ALARM_ARM:
-                return formatCommand(command, "@@M33,{%s},C01,0,22122*00\r\n", Command.KEY_UNIQUE_ID);
+                return formatCommand(command, 'M', "C01,0,22122");
             case Command.TYPE_ALARM_DISARM:
-                return formatCommand(command, "@@M33,{%s},C01,0,22022*00\r\n", Command.KEY_UNIQUE_ID);
+                return formatCommand(command, 'M', "C01,0,22022");
             case Command.TYPE_REQUEST_PHOTO:
-                return formatCommand(command, "@@D46,{%s},D03,1,camera_picture.jpg*00\r\n", Command.KEY_UNIQUE_ID);
+                return formatCommand(command, 'D', "D03,1,camera_picture.jpg");
             default:
                 Log.warning(new UnsupportedOperationException(command.getType()));
                 break;