Refactored four managers

48 files changed, 723 insertions, 1103 deletions

diff --git a/src/org/traccar/api/resource/AttributePermissionResource.java b/src/org/traccar/api/resource/AttributePermissionResource.java
index 1924bcdf1..37e50e371 100644
--- a/src/org/traccar/api/resource/AttributePermissionResource.java
+++ b/src/org/traccar/api/resource/AttributePermissionResource.java
@@ -39,9 +39,9 @@ public class AttributePermissionResource extends BaseResource {
     public Response add(AttributePermission entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkUser(getUserId(), entity.getUserId());
-        Context.getPermissionsManager().checkAttribute(getUserId(), entity.getAttributeId());
+        Context.getPermissionsManager().checkPermission("attribute", getUserId(), entity.getAttributeId());
         Context.getDataManager().linkAttribute(entity.getUserId(), entity.getAttributeId());
-        Context.getAttributesManager().refreshUserAttributes();
+        Context.getAttributesManager().refreshUserItems();
         return Response.ok(entity).build();
     }
 
@@ -49,9 +49,9 @@ public class AttributePermissionResource extends BaseResource {
     public Response remove(AttributePermission entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkUser(getUserId(), entity.getUserId());
-        Context.getPermissionsManager().checkAttribute(getUserId(), entity.getAttributeId());
+        Context.getPermissionsManager().checkPermission("attribute", getUserId(), entity.getAttributeId());
         Context.getDataManager().unlinkAttribute(entity.getUserId(), entity.getAttributeId());
-        Context.getAttributesManager().refreshUserAttributes();
+        Context.getAttributesManager().refreshUserItems();
         return Response.noContent().build();
     }
 
diff --git a/src/org/traccar/api/resource/AttributeResource.java b/src/org/traccar/api/resource/AttributeResource.java
index 4d326779b..c67d9cafe 100644
--- a/src/org/traccar/api/resource/AttributeResource.java
+++ b/src/org/traccar/api/resource/AttributeResource.java
@@ -52,42 +52,42 @@ public class AttributeResource extends BaseResource {
 
         AttributesManager attributesManager = Context.getAttributesManager();
         if (refresh) {
-            attributesManager.refreshAttributes();
+            attributesManager.refreshItems();
         }
 
         Set<Long> result = new HashSet<>();
         if (all) {
             if (Context.getPermissionsManager().isAdmin(getUserId())) {
-                result.addAll(attributesManager.getAllAttributes());
+                result.addAll(attributesManager.getAllItems());
             } else {
                 Context.getPermissionsManager().checkManager(getUserId());
-                result.addAll(attributesManager.getManagedAttributes(getUserId()));
+                result.addAll(attributesManager.getManagedItems(getUserId()));
             }
         } else {
             if (userId == 0) {
                 userId = getUserId();
             }
             Context.getPermissionsManager().checkUser(getUserId(), userId);
-            result.addAll(attributesManager.getUserAttributes(userId));
+            result.addAll(attributesManager.getUserItems(userId));
         }
 
         if (groupId != 0) {
             Context.getPermissionsManager().checkGroup(getUserId(), groupId);
-            result.retainAll(attributesManager.getGroupAttributes(groupId));
+            result.retainAll(attributesManager.getGroupItems(groupId));
         }
 
         if (deviceId != 0) {
             Context.getPermissionsManager().checkDevice(getUserId(), deviceId);
-            result.retainAll(attributesManager.getDeviceAttributes(deviceId));
+            result.retainAll(attributesManager.getDeviceItems(deviceId));
         }
-        return attributesManager.getAttributes(result);
+        return attributesManager.getItems(Attribute.class, result);
 
     }
 
     private Response add(Attribute entity) throws SQLException {
-        Context.getAttributesManager().addAttribute(entity);
+        Context.getAttributesManager().addItem(entity);
         Context.getDataManager().linkAttribute(getUserId(), entity.getId());
-        Context.getAttributesManager().refreshUserAttributes();
+        Context.getAttributesManager().refreshUserItems();
         return Response.ok(entity).build();
     }
 
@@ -127,8 +127,8 @@ public class AttributeResource extends BaseResource {
     @PUT
     public Response update(Attribute entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getPermissionsManager().checkAttribute(getUserId(), entity.getId());
-        Context.getAttributesManager().updateAttribute(entity);
+        Context.getPermissionsManager().checkPermission("attribute", getUserId(), entity.getId());
+        Context.getAttributesManager().updateItem(entity);
         return Response.ok(entity).build();
     }
 
@@ -136,8 +136,8 @@ public class AttributeResource extends BaseResource {
     @DELETE
     public Response remove(@PathParam("id") long id) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getPermissionsManager().checkAttribute(getUserId(), id);
-        Context.getAttributesManager().removeAttribute(id);
+        Context.getPermissionsManager().checkPermission("attribute", getUserId(), id);
+        Context.getAttributesManager().removeItem(id);
         return Response.noContent().build();
     }
 
diff --git a/src/org/traccar/api/resource/CalendarPermissionResource.java b/src/org/traccar/api/resource/CalendarPermissionResource.java
index a49254b6b..3936bcaf3 100644
--- a/src/org/traccar/api/resource/CalendarPermissionResource.java
+++ b/src/org/traccar/api/resource/CalendarPermissionResource.java
@@ -39,9 +39,9 @@ public class CalendarPermissionResource extends BaseResource {
     public Response add(CalendarPermission entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkUser(getUserId(), entity.getUserId());
-        Context.getPermissionsManager().checkCalendar(getUserId(), entity.getCalendarId());
+        Context.getPermissionsManager().checkPermission("calendar", getUserId(), entity.getCalendarId());
         Context.getDataManager().linkCalendar(entity.getUserId(), entity.getCalendarId());
-        Context.getCalendarManager().refreshUserCalendars();
+        Context.getCalendarManager().refreshUserItems();
         return Response.ok(entity).build();
     }
 
@@ -49,9 +49,9 @@ public class CalendarPermissionResource extends BaseResource {
     public Response remove(CalendarPermission entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkUser(getUserId(), entity.getUserId());
-        Context.getPermissionsManager().checkCalendar(getUserId(), entity.getCalendarId());
+        Context.getPermissionsManager().checkPermission("calendar", getUserId(), entity.getCalendarId());
         Context.getDataManager().unlinkCalendar(entity.getUserId(), entity.getCalendarId());
-        Context.getCalendarManager().refreshUserCalendars();
+        Context.getCalendarManager().refreshUserItems();
         return Response.noContent().build();
     }
 }
diff --git a/src/org/traccar/api/resource/CalendarResource.java b/src/org/traccar/api/resource/CalendarResource.java
index 641d3b4b5..be675fc79 100644
--- a/src/org/traccar/api/resource/CalendarResource.java
+++ b/src/org/traccar/api/resource/CalendarResource.java
@@ -33,6 +33,7 @@ import javax.ws.rs.core.Response;
 
 import org.traccar.Context;
 import org.traccar.api.BaseResource;
+import org.traccar.database.CalendarManager;
 import org.traccar.model.Calendar;
 
 @Path("calendars")
@@ -44,28 +45,29 @@ public class CalendarResource extends BaseResource {
     public Collection<Calendar> get(
             @QueryParam("all") boolean all, @QueryParam("userId") long userId) throws SQLException {
 
+        CalendarManager calendarManager = Context.getCalendarManager();
         if (all) {
             if (Context.getPermissionsManager().isAdmin(getUserId())) {
-                return Context.getCalendarManager().getAllCalendars();
+                return calendarManager.getItems(Calendar.class, calendarManager.getAllItems());
             } else {
                 Context.getPermissionsManager().checkManager(getUserId());
-                return Context.getCalendarManager().getManagedCalendars(getUserId());
+                return calendarManager.getItems(Calendar.class, calendarManager.getManagedItems(getUserId()));
             }
         } else {
             if (userId == 0) {
                 userId = getUserId();
             }
             Context.getPermissionsManager().checkUser(getUserId(), userId);
-            return Context.getCalendarManager().getUserCalendars(userId);
+            return calendarManager.getItems(Calendar.class, calendarManager.getUserItems(userId));
         }
     }
 
     @POST
     public Response add(Calendar entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getCalendarManager().addCalendar(entity);
+        Context.getCalendarManager().addItem(entity);
         Context.getDataManager().linkCalendar(getUserId(), entity.getId());
-        Context.getCalendarManager().refreshUserCalendars();
+        Context.getCalendarManager().refreshUserItems();
         return Response.ok(entity).build();
     }
 
@@ -73,8 +75,8 @@ public class CalendarResource extends BaseResource {
     @PUT
     public Response update(Calendar entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getPermissionsManager().checkCalendar(getUserId(), entity.getId());
-        Context.getCalendarManager().updateCalendar(entity);
+        Context.getPermissionsManager().checkPermission("calendar", getUserId(), entity.getId());
+        Context.getCalendarManager().updateItem(entity);
         return Response.ok(entity).build();
     }
 
@@ -82,8 +84,8 @@ public class CalendarResource extends BaseResource {
     @DELETE
     public Response remove(@PathParam("id") long id) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getPermissionsManager().checkCalendar(getUserId(), id);
-        Context.getCalendarManager().removeCalendar(id);
+        Context.getPermissionsManager().checkPermission("calendar", getUserId(), id);
+        Context.getCalendarManager().removeItem(id);
         return Response.noContent().build();
     }
 }
diff --git a/src/org/traccar/api/resource/DeviceAttributeResource.java b/src/org/traccar/api/resource/DeviceAttributeResource.java
index 82d17bcc6..bb833d4db 100644
--- a/src/org/traccar/api/resource/DeviceAttributeResource.java
+++ b/src/org/traccar/api/resource/DeviceAttributeResource.java
@@ -39,7 +39,7 @@ public class DeviceAttributeResource extends BaseResource {
     public Response add(DeviceAttribute entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkDevice(getUserId(), entity.getDeviceId());
-        Context.getPermissionsManager().checkAttribute(getUserId(), entity.getAttributeId());
+        Context.getPermissionsManager().checkPermission("attribute", getUserId(), entity.getAttributeId());
         Context.getDataManager().linkDeviceAttribute(entity.getDeviceId(), entity.getAttributeId());
         Context.getAttributesManager().refresh();
         return Response.ok(entity).build();
@@ -49,7 +49,7 @@ public class DeviceAttributeResource extends BaseResource {
     public Response remove(DeviceAttribute entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkDevice(getUserId(), entity.getDeviceId());
-        Context.getPermissionsManager().checkAttribute(getUserId(), entity.getAttributeId());
+        Context.getPermissionsManager().checkPermission("attribute", getUserId(), entity.getAttributeId());
         Context.getDataManager().unlinkDeviceAttribute(entity.getDeviceId(), entity.getAttributeId());
         Context.getAttributesManager().refresh();
         return Response.noContent().build();
diff --git a/src/org/traccar/api/resource/DeviceDriverResource.java b/src/org/traccar/api/resource/DeviceDriverResource.java
index 341c50909..286f2223f 100644
--- a/src/org/traccar/api/resource/DeviceDriverResource.java
+++ b/src/org/traccar/api/resource/DeviceDriverResource.java
@@ -39,7 +39,7 @@ public class DeviceDriverResource extends BaseResource {
     public Response add(DeviceDriver entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkDevice(getUserId(), entity.getDeviceId());
-        Context.getPermissionsManager().checkDriver(getUserId(), entity.getDriverId());
+        Context.getPermissionsManager().checkPermission("driver", getUserId(), entity.getDriverId());
         Context.getDataManager().linkDeviceDriver(entity.getDeviceId(), entity.getDriverId());
         Context.getDriversManager().refresh();
         return Response.ok(entity).build();
@@ -49,7 +49,7 @@ public class DeviceDriverResource extends BaseResource {
     public Response remove(DeviceDriver entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkDevice(getUserId(), entity.getDeviceId());
-        Context.getPermissionsManager().checkDriver(getUserId(), entity.getDriverId());
+        Context.getPermissionsManager().checkPermission("driver", getUserId(), entity.getDriverId());
         Context.getDataManager().unlinkDeviceDriver(entity.getDeviceId(), entity.getDriverId());
         Context.getDriversManager().refresh();
         return Response.noContent().build();
diff --git a/src/org/traccar/api/resource/DeviceGeofenceResource.java b/src/org/traccar/api/resource/DeviceGeofenceResource.java
index 6254fe3cf..8034e2168 100644
--- a/src/org/traccar/api/resource/DeviceGeofenceResource.java
+++ b/src/org/traccar/api/resource/DeviceGeofenceResource.java
@@ -38,7 +38,7 @@ public class DeviceGeofenceResource extends BaseResource {
     public Response add(DeviceGeofence entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkDevice(getUserId(), entity.getDeviceId());
-        Context.getPermissionsManager().checkGeofence(getUserId(), entity.getGeofenceId());
+        Context.getPermissionsManager().checkPermission("geofence", getUserId(), entity.getGeofenceId());
         Context.getDataManager().linkDeviceGeofence(entity.getDeviceId(), entity.getGeofenceId());
         Context.getGeofenceManager().refresh();
         return Response.ok(entity).build();
@@ -48,7 +48,7 @@ public class DeviceGeofenceResource extends BaseResource {
     public Response remove(DeviceGeofence entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkDevice(getUserId(), entity.getDeviceId());
-        Context.getPermissionsManager().checkGeofence(getUserId(), entity.getGeofenceId());
+        Context.getPermissionsManager().checkPermission("geofence", getUserId(), entity.getGeofenceId());
         Context.getDataManager().unlinkDeviceGeofence(entity.getDeviceId(), entity.getGeofenceId());
         Context.getGeofenceManager().refresh();
         return Response.noContent().build();
diff --git a/src/org/traccar/api/resource/DriverPermissionResource.java b/src/org/traccar/api/resource/DriverPermissionResource.java
index fd1ca7c6d..4d890cae9 100644
--- a/src/org/traccar/api/resource/DriverPermissionResource.java
+++ b/src/org/traccar/api/resource/DriverPermissionResource.java
@@ -40,9 +40,9 @@ public class DriverPermissionResource extends BaseResource {
     public Response add(DriverPermission entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkUser(getUserId(), entity.getUserId());
-        Context.getPermissionsManager().checkDriver(getUserId(), entity.getDriverId());
+        Context.getPermissionsManager().checkPermission("driver", getUserId(), entity.getDriverId());
         Context.getDataManager().linkDriver(entity.getUserId(), entity.getDriverId());
-        Context.getDriversManager().refreshUserDrivers();
+        Context.getDriversManager().refreshUserItems();
         return Response.ok(entity).build();
     }
 
@@ -50,9 +50,9 @@ public class DriverPermissionResource extends BaseResource {
     public Response remove(DriverPermission entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkUser(getUserId(), entity.getUserId());
-        Context.getPermissionsManager().checkDriver(getUserId(), entity.getDriverId());
+        Context.getPermissionsManager().checkPermission("driver", getUserId(), entity.getDriverId());
         Context.getDataManager().unlinkDriver(entity.getUserId(), entity.getDriverId());
-        Context.getDriversManager().refreshUserDrivers();
+        Context.getDriversManager().refreshUserItems();
         return Response.noContent().build();
     }
 
diff --git a/src/org/traccar/api/resource/DriverResource.java b/src/org/traccar/api/resource/DriverResource.java
index 7fe0af473..3d6a12795 100644
--- a/src/org/traccar/api/resource/DriverResource.java
+++ b/src/org/traccar/api/resource/DriverResource.java
@@ -50,44 +50,44 @@ public class DriverResource extends BaseResource {
 
         DriversManager driversManager = Context.getDriversManager();
         if (refresh) {
-            driversManager.refreshDrivers();
+            driversManager.refreshItems();
         }
 
         Set<Long> result = new HashSet<>();
         if (all) {
             if (Context.getPermissionsManager().isAdmin(getUserId())) {
-                result.addAll(driversManager.getAllDrivers());
+                result.addAll(driversManager.getAllItems());
             } else {
                 Context.getPermissionsManager().checkManager(getUserId());
-                result.addAll(driversManager.getManagedDrivers(getUserId()));
+                result.addAll(driversManager.getManagedItems(getUserId()));
             }
         } else {
             if (userId == 0) {
                 userId = getUserId();
             }
             Context.getPermissionsManager().checkUser(getUserId(), userId);
-            result.addAll(driversManager.getUserDrivers(userId));
+            result.addAll(driversManager.getUserItems(userId));
         }
 
         if (groupId != 0) {
             Context.getPermissionsManager().checkGroup(getUserId(), groupId);
-            result.retainAll(driversManager.getGroupDrivers(groupId));
+            result.retainAll(driversManager.getGroupItems(groupId));
         }
 
         if (deviceId != 0) {
             Context.getPermissionsManager().checkDevice(getUserId(), deviceId);
-            result.retainAll(driversManager.getDeviceDrivers(deviceId));
+            result.retainAll(driversManager.getDeviceItems(deviceId));
         }
-        return driversManager.getDrivers(result);
+        return driversManager.getItems(Driver.class, result);
 
     }
 
     @POST
     public Response add(Driver entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getDriversManager().addDriver(entity);
+        Context.getDriversManager().addItem(entity);
         Context.getDataManager().linkDriver(getUserId(), entity.getId());
-        Context.getDriversManager().refreshUserDrivers();
+        Context.getDriversManager().refreshUserItems();
         return Response.ok(entity).build();
     }
 
@@ -95,8 +95,8 @@ public class DriverResource extends BaseResource {
     @PUT
     public Response update(Driver entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getPermissionsManager().checkDriver(getUserId(), entity.getId());
-        Context.getDriversManager().updateDriver(entity);
+        Context.getPermissionsManager().checkPermission("driver", getUserId(), entity.getId());
+        Context.getDriversManager().updateItem(entity);
         return Response.ok(entity).build();
     }
 
@@ -104,8 +104,8 @@ public class DriverResource extends BaseResource {
     @DELETE
     public Response remove(@PathParam("id") long id) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getPermissionsManager().checkDriver(getUserId(), id);
-        Context.getDriversManager().removeDriver(id);
+        Context.getPermissionsManager().checkPermission("driver", getUserId(), id);
+        Context.getDriversManager().removeItem(id);
         return Response.noContent().build();
     }
 
diff --git a/src/org/traccar/api/resource/EventResource.java b/src/org/traccar/api/resource/EventResource.java
index 0ef5456af..9b43bf4b0 100644
--- a/src/org/traccar/api/resource/EventResource.java
+++ b/src/org/traccar/api/resource/EventResource.java
@@ -25,7 +25,7 @@ public class EventResource extends BaseResource {
         Event event = Context.getDataManager().getEvent(id);
         Context.getPermissionsManager().checkDevice(getUserId(), event.getDeviceId());
         if (event.getGeofenceId() != 0) {
-            Context.getPermissionsManager().checkGeofence(getUserId(), event.getGeofenceId());
+            Context.getPermissionsManager().checkPermission("geofence", getUserId(), event.getGeofenceId());
         }
         return event;
     }
diff --git a/src/org/traccar/api/resource/GeofencePermissionResource.java b/src/org/traccar/api/resource/GeofencePermissionResource.java
index 8faa63d85..a569e56fd 100644
--- a/src/org/traccar/api/resource/GeofencePermissionResource.java
+++ b/src/org/traccar/api/resource/GeofencePermissionResource.java
@@ -37,9 +37,9 @@ public class GeofencePermissionResource extends BaseResource {
     public Response add(GeofencePermission entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkUser(getUserId(), entity.getUserId());
-        Context.getPermissionsManager().checkGeofence(getUserId(), entity.getGeofenceId());
+        Context.getPermissionsManager().checkPermission("geofence", getUserId(), entity.getGeofenceId());
         Context.getDataManager().linkGeofence(entity.getUserId(), entity.getGeofenceId());
-        Context.getGeofenceManager().refreshUserGeofences();
+        Context.getGeofenceManager().refreshUserItems();
         return Response.ok(entity).build();
     }
 
@@ -47,9 +47,9 @@ public class GeofencePermissionResource extends BaseResource {
     public Response remove(GeofencePermission entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkUser(getUserId(), entity.getUserId());
-        Context.getPermissionsManager().checkGeofence(getUserId(), entity.getGeofenceId());
+        Context.getPermissionsManager().checkPermission("geofence", getUserId(), entity.getGeofenceId());
         Context.getDataManager().unlinkGeofence(entity.getUserId(), entity.getGeofenceId());
-        Context.getGeofenceManager().refreshUserGeofences();
+        Context.getGeofenceManager().refreshUserItems();
         return Response.noContent().build();
     }
 
diff --git a/src/org/traccar/api/resource/GeofenceResource.java b/src/org/traccar/api/resource/GeofenceResource.java
index d5acf106a..4a52822cc 100644
--- a/src/org/traccar/api/resource/GeofenceResource.java
+++ b/src/org/traccar/api/resource/GeofenceResource.java
@@ -49,44 +49,44 @@ public class GeofenceResource extends BaseResource {
 
         GeofenceManager geofenceManager = Context.getGeofenceManager();
         if (refresh) {
-            geofenceManager.refreshGeofences();
+            geofenceManager.refreshItems();
         }
 
         Set<Long> result = new HashSet<>();
         if (all) {
             if (Context.getPermissionsManager().isAdmin(getUserId())) {
-                result.addAll(geofenceManager.getAllGeofencesIds());
+                result.addAll(geofenceManager.getAllItems());
             } else {
                 Context.getPermissionsManager().checkManager(getUserId());
-                result.addAll(geofenceManager.getManagedGeofencesIds(getUserId()));
+                result.addAll(geofenceManager.getManagedItems(getUserId()));
             }
         } else {
             if (userId == 0) {
                 userId = getUserId();
             }
             Context.getPermissionsManager().checkUser(getUserId(), userId);
-            result.addAll(geofenceManager.getUserGeofencesIds(userId));
+            result.addAll(geofenceManager.getUserItems(userId));
         }
 
         if (groupId != 0) {
             Context.getPermissionsManager().checkGroup(getUserId(), groupId);
-            result.retainAll(geofenceManager.getGroupGeofencesIds(groupId));
+            result.retainAll(geofenceManager.getGroupItems(groupId));
         }
 
         if (deviceId != 0) {
             Context.getPermissionsManager().checkDevice(getUserId(), deviceId);
-            result.retainAll(geofenceManager.getDeviceGeofencesIds(deviceId));
+            result.retainAll(geofenceManager.getDeviceItems(deviceId));
         }
-        return geofenceManager.getGeofences(result);
+        return geofenceManager.getItems(Geofence.class, result);
 
     }
 
     @POST
     public Response add(Geofence entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getDataManager().addGeofence(entity);
+        Context.getGeofenceManager().addItem(entity);
         Context.getDataManager().linkGeofence(getUserId(), entity.getId());
-        Context.getGeofenceManager().refreshGeofences();
+        Context.getGeofenceManager().refreshUserItems();
         return Response.ok(entity).build();
     }
 
@@ -94,8 +94,8 @@ public class GeofenceResource extends BaseResource {
     @PUT
     public Response update(Geofence entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getPermissionsManager().checkGeofence(getUserId(), entity.getId());
-        Context.getGeofenceManager().updateGeofence(entity);
+        Context.getPermissionsManager().checkPermission("geofence", getUserId(), entity.getId());
+        Context.getGeofenceManager().updateItem(entity);
         return Response.ok(entity).build();
     }
 
@@ -103,9 +103,8 @@ public class GeofenceResource extends BaseResource {
     @DELETE
     public Response remove(@PathParam("id") long id) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
-        Context.getPermissionsManager().checkGeofence(getUserId(), id);
-        Context.getDataManager().removeGeofence(id);
-        Context.getGeofenceManager().refreshGeofences();
+        Context.getPermissionsManager().checkPermission("geofence", getUserId(), id);
+        Context.getGeofenceManager().removeItem(id);
         return Response.noContent().build();
     }
 
diff --git a/src/org/traccar/api/resource/GroupAttributeResource.java b/src/org/traccar/api/resource/GroupAttributeResource.java
index d8b8b58c9..5df63194e 100644
--- a/src/org/traccar/api/resource/GroupAttributeResource.java
+++ b/src/org/traccar/api/resource/GroupAttributeResource.java
@@ -39,7 +39,7 @@ public class GroupAttributeResource extends BaseResource {
     public Response add(GroupAttribute entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkGroup(getUserId(), entity.getGroupId());
-        Context.getPermissionsManager().checkAttribute(getUserId(), entity.getAttributeId());
+        Context.getPermissionsManager().checkPermission("attribute", getUserId(), entity.getAttributeId());
         Context.getDataManager().linkGroupAttribute(entity.getGroupId(), entity.getAttributeId());
         Context.getAttributesManager().refresh();
         return Response.ok(entity).build();
@@ -49,7 +49,7 @@ public class GroupAttributeResource extends BaseResource {
     public Response remove(GroupAttribute entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkGroup(getUserId(), entity.getGroupId());
-        Context.getPermissionsManager().checkAttribute(getUserId(), entity.getAttributeId());
+        Context.getPermissionsManager().checkPermission("attribute", getUserId(), entity.getAttributeId());
         Context.getDataManager().unlinkGroupAttribute(entity.getGroupId(), entity.getAttributeId());
         Context.getAttributesManager().refresh();
         return Response.noContent().build();
diff --git a/src/org/traccar/api/resource/GroupDriverResource.java b/src/org/traccar/api/resource/GroupDriverResource.java
index 76fc2892c..71c1aca29 100644
--- a/src/org/traccar/api/resource/GroupDriverResource.java
+++ b/src/org/traccar/api/resource/GroupDriverResource.java
@@ -39,7 +39,7 @@ public class GroupDriverResource extends BaseResource {
     public Response add(GroupDriver entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkGroup(getUserId(), entity.getGroupId());
-        Context.getPermissionsManager().checkDriver(getUserId(), entity.getDriverId());
+        Context.getPermissionsManager().checkPermission("driver", getUserId(), entity.getDriverId());
         Context.getDataManager().linkGroupDriver(entity.getGroupId(), entity.getDriverId());
         Context.getDriversManager().refresh();
         return Response.ok(entity).build();
@@ -49,7 +49,7 @@ public class GroupDriverResource extends BaseResource {
     public Response remove(GroupDriver entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkGroup(getUserId(), entity.getGroupId());
-        Context.getPermissionsManager().checkDriver(getUserId(), entity.getDriverId());
+        Context.getPermissionsManager().checkPermission("driver", getUserId(), entity.getDriverId());
         Context.getDataManager().unlinkGroupDriver(entity.getGroupId(), entity.getDriverId());
         Context.getDriversManager().refresh();
         return Response.noContent().build();
diff --git a/src/org/traccar/api/resource/GroupGeofenceResource.java b/src/org/traccar/api/resource/GroupGeofenceResource.java
index 81fd4e45f..14000c4b5 100644
--- a/src/org/traccar/api/resource/GroupGeofenceResource.java
+++ b/src/org/traccar/api/resource/GroupGeofenceResource.java
@@ -37,7 +37,7 @@ public class GroupGeofenceResource extends BaseResource {
     public Response add(GroupGeofence entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkGroup(getUserId(), entity.getGroupId());
-        Context.getPermissionsManager().checkGeofence(getUserId(), entity.getGeofenceId());
+        Context.getPermissionsManager().checkPermission("geofence", getUserId(), entity.getGeofenceId());
         Context.getDataManager().linkGroupGeofence(entity.getGroupId(), entity.getGeofenceId());
         Context.getGeofenceManager().refresh();
         return Response.ok(entity).build();
@@ -47,7 +47,7 @@ public class GroupGeofenceResource extends BaseResource {
     public Response remove(GroupGeofence entity) throws SQLException {
         Context.getPermissionsManager().checkReadonly(getUserId());
         Context.getPermissionsManager().checkGroup(getUserId(), entity.getGroupId());
-        Context.getPermissionsManager().checkGeofence(getUserId(), entity.getGeofenceId());
+        Context.getPermissionsManager().checkPermission("geofence", getUserId(), entity.getGeofenceId());
         Context.getDataManager().unlinkGroupGeofence(entity.getGroupId(), entity.getGeofenceId());
         Context.getGeofenceManager().refresh();
         return Response.noContent().build();
diff --git a/src/org/traccar/api/resource/UserResource.java b/src/org/traccar/api/resource/UserResource.java
index 4d8a8b3a4..b9187fdbb 100644
--- a/src/org/traccar/api/resource/UserResource.java
+++ b/src/org/traccar/api/resource/UserResource.java
@@ -104,7 +104,7 @@ public class UserResource extends BaseResource {
         Context.getPermissionsManager().checkUser(getUserId(), id);
         Context.getPermissionsManager().removeUser(id);
         if (Context.getGeofenceManager() != null) {
-            Context.getGeofenceManager().refreshUserGeofences();
+            Context.getGeofenceManager().refreshUserItems();
         }
         if (Context.getNotificationManager() != null) {
             Context.getNotificationManager().refresh();
diff --git a/src/org/traccar/database/AttributesManager.java b/src/org/traccar/database/AttributesManager.java
index 362d6130f..88bedfba4 100644
--- a/src/org/traccar/database/AttributesManager.java
+++ b/src/org/traccar/database/AttributesManager.java
@@ -17,183 +17,30 @@
 package org.traccar.database;
 
 import java.sql.SQLException;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
 
-import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.AttributePermission;
 import org.traccar.model.Attribute;
-import org.traccar.model.Device;
 import org.traccar.model.DeviceAttribute;
 import org.traccar.model.GroupAttribute;
+import org.traccar.model.Identifiable;
 
-public class AttributesManager {
-
-    private final DataManager dataManager;
-
-    private final Map<Long, Attribute> attributes = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> deviceAttributes = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> deviceAttributesWithGroups = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> groupAttributes = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> userAttributes = new ConcurrentHashMap<>();
+public class AttributesManager extends ExtendedObjectManager {
 
     public AttributesManager(DataManager dataManager) {
-        this.dataManager = dataManager;
-        refreshAttributes();
-    }
-
-    public Set<Long> getUserAttributes(long userId) {
-        if (!userAttributes.containsKey(userId)) {
-            userAttributes.put(userId, new HashSet<Long>());
-        }
-        return userAttributes.get(userId);
-    }
-
-    public Set<Long> getGroupAttributes(long groupId) {
-        if (!groupAttributes.containsKey(groupId)) {
-            groupAttributes.put(groupId, new HashSet<Long>());
-        }
-        return groupAttributes.get(groupId);
-    }
-
-    public Set<Long> getDeviceAttributes(long deviceId) {
-        return getDeviceAttributes(deviceAttributes, deviceId);
-    }
-
-    public Set<Long> getAllDeviceAttributes(long deviceId) {
-        return getDeviceAttributes(deviceAttributesWithGroups, deviceId);
-    }
-
-    private Set<Long> getDeviceAttributes(Map<Long, Set<Long>> deviceAttributes, long deviceId) {
-        if (!deviceAttributes.containsKey(deviceId)) {
-            deviceAttributes.put(deviceId, new HashSet<Long>());
-        }
-        return deviceAttributes.get(deviceId);
-    }
-
-    public final void refreshAttributes() {
-        if (dataManager != null) {
-            try {
-                attributes.clear();
-                for (Attribute attribute : dataManager.getAttributes()) {
-                    attributes.put(attribute.getId(), attribute);
-                }
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-        refreshUserAttributes();
+        super(dataManager, Attribute.class, AttributePermission.class, DeviceAttribute.class, GroupAttribute.class);
+        refreshItems();
         refresh();
     }
 
-    public final void refreshUserAttributes() {
-        if (dataManager != null) {
-            try {
-                userAttributes.clear();
-                for (AttributePermission attributePermission : dataManager.getAttributePermissions()) {
-                    getUserAttributes(attributePermission.getUserId()).add(attributePermission.getAttributeId());
-                }
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-    }
-
-    public final void refresh() {
-        if (dataManager != null) {
-            try {
-
-                Collection<GroupAttribute> databaseGroupAttributes = dataManager.getGroupAttributes();
-
-                groupAttributes.clear();
-                for (GroupAttribute groupAttribute : databaseGroupAttributes) {
-                    getGroupAttributes(groupAttribute.getGroupId()).add(groupAttribute.getAttributeId());
-                }
-
-                Collection<DeviceAttribute> databaseDeviceAttributes = dataManager.getDeviceAttributes();
-                Collection<Device> allDevices = Context.getDeviceManager().getAllDevices();
-
-                deviceAttributes.clear();
-                deviceAttributesWithGroups.clear();
-
-                for (DeviceAttribute deviceAttribute : databaseDeviceAttributes) {
-                    getDeviceAttributes(deviceAttribute.getDeviceId())
-                        .add(deviceAttribute.getAttributeId());
-                    getAllDeviceAttributes(deviceAttribute.getDeviceId())
-                        .add(deviceAttribute.getAttributeId());
-                }
-
-                for (Device device : allDevices) {
-                    long groupId = device.getGroupId();
-                    while (groupId != 0) {
-                        getAllDeviceAttributes(device.getId()).addAll(getGroupAttributes(groupId));
-                        if (Context.getDeviceManager().getGroupById(groupId) != null) {
-                            groupId = Context.getDeviceManager().getGroupById(groupId).getGroupId();
-                        } else {
-                            groupId = 0;
-                        }
-                    }
-                }
-
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-    }
-
-    public void addAttribute(Attribute attribute) throws SQLException {
-        dataManager.addAttribute(attribute);
-        attributes.put(attribute.getId(), attribute);
-    }
-
-    public void updateAttribute(Attribute attribute) throws SQLException {
-        dataManager.updateAttribute(attribute);
-        Attribute cachedAttribute = attributes.get(attribute.getId());
+    @Override
+    public void updateItem(Identifiable item) throws SQLException {
+        Attribute attribute = (Attribute) item;
+        getDataManager().updateObject(attribute);
+        Attribute cachedAttribute = (Attribute) getById(item.getId());
         cachedAttribute.setDescription(attribute.getDescription());
         cachedAttribute.setAttribute(attribute.getAttribute());
         cachedAttribute.setExpression(attribute.getExpression());
         cachedAttribute.setType(attribute.getType());
     }
 
-    public void removeAttribute(long computedAttributeId) throws SQLException {
-        dataManager.removeAttribute(computedAttributeId);
-        attributes.remove(computedAttributeId);
-        refreshUserAttributes();
-        refresh();
-    }
-
-    public boolean checkAttribute(long userId, long attributeId) {
-        return getUserAttributes(userId).contains(attributeId);
-    }
-
-    public Attribute getAttribute(long id) {
-        return attributes.get(id);
-    }
-
-    public final Collection<Attribute> getAttributes(Set<Long> attributeIds) {
-        Collection<Attribute> result = new LinkedList<>();
-        for (long attributeId : attributeIds) {
-            result.add(getAttribute(attributeId));
-        }
-        return result;
-    }
-
-    public final Set<Long> getAllAttributes() {
-        return attributes.keySet();
-    }
-
-    public final Set<Long> getManagedAttributes(long userId) {
-        Set<Long> attributes = new HashSet<>();
-        attributes.addAll(getUserAttributes(userId));
-        for (long managedUserId : Context.getPermissionsManager().getUserPermissions(userId)) {
-            attributes.addAll(getUserAttributes(managedUserId));
-        }
-        return attributes;
-    }
-
 }
diff --git a/src/org/traccar/database/CalendarManager.java b/src/org/traccar/database/CalendarManager.java
index 31d484327..e00b4faa6 100644
--- a/src/org/traccar/database/CalendarManager.java
+++ b/src/org/traccar/database/CalendarManager.java
@@ -16,107 +16,14 @@
  */
 package org.traccar.database;
 
-import java.sql.SQLException;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
-
-import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Calendar;
 import org.traccar.model.CalendarPermission;
 
-public class CalendarManager {
-
-    private final DataManager dataManager;
-
-    private final Map<Long, Calendar> calendars = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> userCalendars = new ConcurrentHashMap<>();
+public class CalendarManager extends SimpleObjectManager {
 
     public CalendarManager(DataManager dataManager) {
-        this.dataManager = dataManager;
-        refreshCalendars();
-    }
-
-    public final void refreshCalendars() {
-        if (dataManager != null) {
-            try {
-                calendars.clear();
-                for (Calendar calendar : dataManager.getCalendars()) {
-                    calendars.put(calendar.getId(), calendar);
-                }
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-        refreshUserCalendars();
-    }
-
-    private Set<Long> getUserCalendarIds(long userId) {
-        if (!userCalendars.containsKey(userId)) {
-            userCalendars.put(userId, new HashSet<Long>());
-        }
-        return userCalendars.get(userId);
-    }
-
-    public Collection<Calendar> getUserCalendars(long userId) {
-        ArrayList<Calendar> result = new ArrayList<>();
-        for (long calendarId : getUserCalendarIds(userId)) {
-            result.add(calendars.get(calendarId));
-        }
-        return result;
-    }
-
-    public Collection<Calendar> getManagedCalendars(long userId) {
-        ArrayList<Calendar> result = new ArrayList<>();
-        result.addAll(getUserCalendars(userId));
-        for (long managedUserId : Context.getPermissionsManager().getUserPermissions(userId)) {
-            result.addAll(getUserCalendars(managedUserId));
-        }
-        return result;
-    }
-
-    public final void refreshUserCalendars() {
-        if (dataManager != null) {
-            try {
-                userCalendars.clear();
-                for (CalendarPermission calendarsPermission : dataManager.getCalendarPermissions()) {
-                    getUserCalendarIds(calendarsPermission.getUserId()).add(calendarsPermission.getCalendarId());
-                }
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-    }
-
-    public Calendar getCalendar(long calendarId) {
-        return calendars.get(calendarId);
-    }
-
-    public final void addCalendar(Calendar calendar) throws SQLException {
-        dataManager.addCalendar(calendar);
-        calendars.put(calendar.getId(), calendar);
-    }
-
-    public final void updateCalendar(Calendar calendar) throws SQLException {
-        dataManager.updateCalendar(calendar);
-        calendars.put(calendar.getId(), calendar);
-    }
-
-    public final void removeCalendar(long calendarId) throws SQLException {
-        dataManager.removeCalendar(calendarId);
-        calendars.remove(calendarId);
-        refreshUserCalendars();
+        super(dataManager, Calendar.class, CalendarPermission.class);
+        refreshItems();
     }
 
-    public Collection<Calendar> getAllCalendars() {
-        return calendars.values();
-    }
-
-    public boolean checkCalendar(long userId, long calendarId) {
-        return getUserCalendarIds(userId).contains(calendarId);
-    }
 }
diff --git a/src/org/traccar/database/DataManager.java b/src/org/traccar/database/DataManager.java
index 1c2a66bcf..4bf4b1b9a 100644
--- a/src/org/traccar/database/DataManager.java
+++ b/src/org/traccar/database/DataManager.java
@@ -38,31 +38,18 @@ import liquibase.resource.ResourceAccessor;
 import org.traccar.Config;
 import org.traccar.helper.Log;
 import org.traccar.model.AttributeAlias;
-import org.traccar.model.AttributePermission;
-import org.traccar.model.Calendar;
-import org.traccar.model.CalendarPermission;
-import org.traccar.model.Attribute;
 import org.traccar.model.Device;
-import org.traccar.model.DeviceAttribute;
-import org.traccar.model.DeviceDriver;
 import org.traccar.model.DevicePermission;
-import org.traccar.model.Driver;
-import org.traccar.model.DriverPermission;
 import org.traccar.model.Event;
-import org.traccar.model.Geofence;
 import org.traccar.model.Group;
-import org.traccar.model.GroupAttribute;
-import org.traccar.model.GroupDriver;
-import org.traccar.model.GroupGeofence;
 import org.traccar.model.GroupPermission;
+import org.traccar.model.Identifiable;
 import org.traccar.model.Notification;
 import org.traccar.model.Position;
 import org.traccar.model.Server;
 import org.traccar.model.Statistics;
 import org.traccar.model.User;
 import org.traccar.model.UserPermission;
-import org.traccar.model.DeviceGeofence;
-import org.traccar.model.GeofencePermission;
 
 import com.zaxxer.hikari.HikariConfig;
 import com.zaxxer.hikari.HikariDataSource;
@@ -362,34 +349,6 @@ public class DataManager {
                 .executeQuery(Event.class);
     }
 
-    public Collection<Geofence> getGeofences() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectGeofencesAll"))
-                .executeQuery(Geofence.class);
-    }
-
-    public void addGeofence(Geofence geofence) throws SQLException {
-        geofence.setId(QueryBuilder.create(dataSource, getQuery("database.insertGeofence"), true)
-                .setObject(geofence)
-                .executeUpdate());
-    }
-
-    public void updateGeofence(Geofence geofence) throws SQLException {
-        QueryBuilder.create(dataSource, getQuery("database.updateGeofence"))
-                .setObject(geofence)
-                .executeUpdate();
-    }
-
-    public void removeGeofence(long geofenceId) throws SQLException {
-        QueryBuilder.create(dataSource, getQuery("database.deleteGeofence"))
-                .setLong("id", geofenceId)
-                .executeUpdate();
-    }
-
-    public Collection<GeofencePermission> getGeofencePermissions() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectGeofencePermissions"))
-                .executeQuery(GeofencePermission.class);
-    }
-
     public void linkGeofence(long userId, long geofenceId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkGeofence"))
                 .setLong("userId", userId)
@@ -404,11 +363,6 @@ public class DataManager {
                 .executeUpdate();
     }
 
-    public Collection<GroupGeofence> getGroupGeofences() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectGroupGeofences"))
-                .executeQuery(GroupGeofence.class);
-    }
-
     public void linkGroupGeofence(long groupId, long geofenceId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkGroupGeofence"))
                 .setLong("groupId", groupId)
@@ -423,11 +377,6 @@ public class DataManager {
                 .executeUpdate();
     }
 
-    public Collection<DeviceGeofence> getDeviceGeofences() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectDeviceGeofences"))
-                .executeQuery(DeviceGeofence.class);
-    }
-
     public void linkDeviceGeofence(long deviceId, long geofenceId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkDeviceGeofence"))
                 .setLong("deviceId", deviceId)
@@ -501,34 +450,6 @@ public class DataManager {
                 .executeUpdate());
     }
 
-    public Collection<Calendar> getCalendars() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectCalendarsAll"))
-                .executeQuery(Calendar.class);
-    }
-
-    public void addCalendar(Calendar calendar) throws SQLException {
-        calendar.setId(QueryBuilder.create(dataSource, getQuery("database.insertCalendar"), true)
-                .setObject(calendar)
-                .executeUpdate());
-    }
-
-    public void updateCalendar(Calendar calendar) throws SQLException {
-        QueryBuilder.create(dataSource, getQuery("database.updateCalendar"))
-                .setObject(calendar)
-                .executeUpdate();
-    }
-
-    public void removeCalendar(long calendarId) throws SQLException {
-        QueryBuilder.create(dataSource, getQuery("database.deleteCalendar"))
-                .setLong("id", calendarId)
-                .executeUpdate();
-    }
-
-    public Collection<CalendarPermission> getCalendarPermissions() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectCalendarPermissions"))
-                .executeQuery(CalendarPermission.class);
-    }
-
     public void linkCalendar(long userId, long calendarId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkCalendar"))
                 .setLong("userId", userId)
@@ -562,34 +483,6 @@ public class DataManager {
                 .executeUpdate();
     }
 
-    public Collection<Attribute> getAttributes() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectAttributes"))
-                .executeQuery(Attribute.class);
-    }
-
-    public void addAttribute(Attribute attribute) throws SQLException {
-        attribute.setId(QueryBuilder.create(dataSource, getQuery("database.insertAttribute"), true)
-                .setObject(attribute)
-                .executeUpdate());
-    }
-
-    public void updateAttribute(Attribute attribute) throws SQLException {
-        QueryBuilder.create(dataSource, getQuery("database.updateAttribute"))
-                .setObject(attribute)
-                .executeUpdate();
-    }
-
-    public void removeAttribute(long computedAttributeId) throws SQLException {
-        QueryBuilder.create(dataSource, getQuery("database.deleteAttribute"))
-                .setLong("id", computedAttributeId)
-                .executeUpdate();
-    }
-
-    public Collection<AttributePermission> getAttributePermissions() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectAttributePermissions"))
-                .executeQuery(AttributePermission.class);
-    }
-
     public void linkAttribute(long userId, long attributeId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkAttribute"))
                 .setLong("userId", userId)
@@ -604,11 +497,6 @@ public class DataManager {
                 .executeUpdate();
     }
 
-    public Collection<GroupAttribute> getGroupAttributes() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectGroupAttributes"))
-                .executeQuery(GroupAttribute.class);
-    }
-
     public void linkGroupAttribute(long groupId, long attributeId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkGroupAttribute"))
                 .setLong("groupId", groupId)
@@ -623,11 +511,6 @@ public class DataManager {
                 .executeUpdate();
     }
 
-    public Collection<DeviceAttribute> getDeviceAttributes() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectDeviceAttributes"))
-                .executeQuery(DeviceAttribute.class);
-    }
-
     public void linkDeviceAttribute(long deviceId, long attributeId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkDeviceAttribute"))
                 .setLong("deviceId", deviceId)
@@ -642,34 +525,6 @@ public class DataManager {
                 .executeUpdate();
     }
 
-    public Collection<Driver> getDrivers() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectDrivers"))
-                .executeQuery(Driver.class);
-    }
-
-    public void addDriver(Driver driver) throws SQLException {
-        driver.setId(QueryBuilder.create(dataSource, getQuery("database.insertDriver"), true)
-                .setObject(driver)
-                .executeUpdate());
-    }
-
-    public void updateDriver(Driver driver) throws SQLException {
-        QueryBuilder.create(dataSource, getQuery("database.updateDriver"))
-                .setObject(driver)
-                .executeUpdate();
-    }
-
-    public void removeDriver(long driverId) throws SQLException {
-        QueryBuilder.create(dataSource, getQuery("database.deleteDriver"))
-                .setLong("id", driverId)
-                .executeUpdate();
-    }
-
-    public Collection<DriverPermission> getDriverPermissions() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectDriverPermissions"))
-                .executeQuery(DriverPermission.class);
-    }
-
     public void linkDriver(long userId, long driverId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkDriver"))
                 .setLong("userId", userId)
@@ -684,11 +539,6 @@ public class DataManager {
                 .executeUpdate();
     }
 
-    public Collection<GroupDriver> getGroupDrivers() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectGroupDrivers"))
-                .executeQuery(GroupDriver.class);
-    }
-
     public void linkGroupDriver(long groupId, long driverId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkGroupDriver"))
                 .setLong("groupId", groupId)
@@ -703,11 +553,6 @@ public class DataManager {
                 .executeUpdate();
     }
 
-    public Collection<DeviceDriver> getDeviceDrivers() throws SQLException {
-        return QueryBuilder.create(dataSource, getQuery("database.selectDeviceDrivers"))
-                .executeQuery(DeviceDriver.class);
-    }
-
     public void linkDeviceDriver(long deviceId, long driverId) throws SQLException {
         QueryBuilder.create(dataSource, getQuery("database.linkDeviceDriver"))
                 .setLong("deviceId", deviceId)
@@ -722,4 +567,30 @@ public class DataManager {
                 .executeUpdate();
     }
 
+    public <T> Collection<T> getObjects(Class<T> clazz) throws SQLException {
+        String query = "database.select" + clazz.getSimpleName() + "s";
+        return QueryBuilder.create(dataSource, getQuery(query)).executeQuery(clazz);
+    }
+
+    public void addObject(Identifiable entity) throws SQLException {
+        String query = "database.insert" + entity.getClass().getSimpleName();
+        entity.setId(QueryBuilder.create(dataSource, getQuery(query), true)
+                .setObject(entity)
+                .executeUpdate());
+    }
+
+    public void updateObject(Identifiable entity) throws SQLException {
+        String query = "database.update" + entity.getClass().getSimpleName();
+        QueryBuilder.create(dataSource, getQuery(query))
+                .setObject(entity)
+                .executeUpdate();
+    }
+
+    public void removeObject(Class<? extends Identifiable> clazz, long entityId) throws SQLException {
+        String query = "database.delete" + clazz.getSimpleName();
+        QueryBuilder.create(dataSource, getQuery(query))
+                .setLong("id", entityId)
+                .executeUpdate();
+    }
+
 }
diff --git a/src/org/traccar/database/DriversManager.java b/src/org/traccar/database/DriversManager.java
index e89d59311..391708f64 100644
--- a/src/org/traccar/database/DriversManager.java
+++ b/src/org/traccar/database/DriversManager.java
@@ -17,147 +17,53 @@
 package org.traccar.database;
 
 import java.sql.SQLException;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.traccar.Context;
 import org.traccar.helper.Log;
-import org.traccar.model.Device;
 import org.traccar.model.DeviceDriver;
 import org.traccar.model.Driver;
 import org.traccar.model.DriverPermission;
 import org.traccar.model.GroupDriver;
+import org.traccar.model.Identifiable;
 
-public class DriversManager {
+public class DriversManager extends ExtendedObjectManager {
 
-    private final DataManager dataManager;
-
-    private final Map<Long, Driver> drivers = new ConcurrentHashMap<>();
     private final Map<String, Driver> driversByUniqueId = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> deviceDrivers = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> deviceDriversWithGroups = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> groupDrivers = new ConcurrentHashMap<>();
-    private final Map<Long, Set<Long>> userDrivers = new ConcurrentHashMap<>();
 
     public DriversManager(DataManager dataManager) {
-        this.dataManager = dataManager;
-        refreshDrivers();
-    }
-
-    public Set<Long> getUserDrivers(long userId) {
-        if (!userDrivers.containsKey(userId)) {
-            userDrivers.put(userId, new HashSet<Long>());
-        }
-        return userDrivers.get(userId);
-    }
-
-    public Set<Long> getGroupDrivers(long groupId) {
-        if (!groupDrivers.containsKey(groupId)) {
-            groupDrivers.put(groupId, new HashSet<Long>());
-        }
-        return groupDrivers.get(groupId);
-    }
-
-    public Set<Long> getDeviceDrivers(long deviceId) {
-        return getDeviceDrivers(deviceDrivers, deviceId);
-    }
-
-    public Set<Long> getAllDeviceDrivers(long deviceId) {
-        return getDeviceDrivers(deviceDriversWithGroups, deviceId);
-    }
-
-    private Set<Long> getDeviceDrivers(Map<Long, Set<Long>> deviceDrivers, long deviceId) {
-        if (!deviceDrivers.containsKey(deviceId)) {
-            deviceDrivers.put(deviceId, new HashSet<Long>());
-        }
-        return deviceDrivers.get(deviceId);
-    }
-
-    public final void refreshDrivers() {
-        if (dataManager != null) {
-            try {
-                drivers.clear();
-                driversByUniqueId.clear();
-                for (Driver driver : dataManager.getDrivers()) {
-                    drivers.put(driver.getId(), driver);
-                    driversByUniqueId.put(driver.getUniqueId(), driver);
-                }
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-        refreshUserDrivers();
+        super(dataManager, Driver.class, DriverPermission.class, DeviceDriver.class, GroupDriver.class);
+        refreshItems();
         refresh();
     }
 
-    public final void refreshUserDrivers() {
-        if (dataManager != null) {
+    @Override
+    public void refreshItems() {
+        if (getDataManager() != null) {
             try {
-                userDrivers.clear();
-                for (DriverPermission driverPermission : dataManager.getDriverPermissions()) {
-                    getUserDrivers(driverPermission.getUserId()).add(driverPermission.getDriverId());
+                clearItems();
+                for (Identifiable item : getDataManager().getObjects(getBaseClass())) {
+                    putItem(item.getId(), item);
+                    driversByUniqueId.put(((Driver) item).getUniqueId(), (Driver) item);
                 }
             } catch (SQLException error) {
                 Log.warning(error);
             }
         }
+        refreshUserItems();
     }
 
-    public final void refresh() {
-        if (dataManager != null) {
-            try {
-
-                Collection<GroupDriver> databaseGroupDrivers = dataManager.getGroupDrivers();
-
-                groupDrivers.clear();
-                for (GroupDriver groupDriver : databaseGroupDrivers) {
-                    getGroupDrivers(groupDriver.getGroupId()).add(groupDriver.getDriverId());
-                }
-
-                Collection<DeviceDriver> databaseDeviceDrivers = dataManager.getDeviceDrivers();
-                Collection<Device> allDevices = Context.getDeviceManager().getAllDevices();
-
-                deviceDrivers.clear();
-                deviceDriversWithGroups.clear();
-
-                for (DeviceDriver deviceAttribute : databaseDeviceDrivers) {
-                    getDeviceDrivers(deviceAttribute.getDeviceId())
-                        .add(deviceAttribute.getDriverId());
-                    getAllDeviceDrivers(deviceAttribute.getDeviceId())
-                        .add(deviceAttribute.getDriverId());
-                }
-
-                for (Device device : allDevices) {
-                    long groupId = device.getGroupId();
-                    while (groupId != 0) {
-                        getAllDeviceDrivers(device.getId()).addAll(getGroupDrivers(groupId));
-                        if (Context.getDeviceManager().getGroupById(groupId) != null) {
-                            groupId = Context.getDeviceManager().getGroupById(groupId).getGroupId();
-                        } else {
-                            groupId = 0;
-                        }
-                    }
-                }
-
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-    }
-
-    public void addDriver(Driver driver) throws SQLException {
-        dataManager.addDriver(driver);
-        drivers.put(driver.getId(), driver);
-        driversByUniqueId.put(driver.getUniqueId(), driver);
+    @Override
+    public void addItem(Identifiable item) throws SQLException {
+        super.addItem(item);
+        driversByUniqueId.put(((Driver) item).getUniqueId(), (Driver) item);
     }
 
-    public void updateDriver(Driver driver) throws SQLException {
-        dataManager.updateDriver(driver);
-        Driver cachedDriver = drivers.get(driver.getId());
+    @Override
+    public void updateItem(Identifiable item) throws SQLException {
+        Driver driver = (Driver) item;
+        getDataManager().updateObject(driver);
+        Driver cachedDriver = (Driver) getById(driver.getId());
         cachedDriver.setName(driver.getName());
         if (!driver.getUniqueId().equals(cachedDriver.getUniqueId())) {
             driversByUniqueId.remove(cachedDriver.getUniqueId());
@@ -167,47 +73,20 @@ public class DriversManager {
         cachedDriver.setAttributes(driver.getAttributes());
     }
 
-    public void removeDriver(long driverId) throws SQLException {
-        dataManager.removeDriver(driverId);
-        if (drivers.containsKey(driverId)) {
-            String driverUniqueId = drivers.get(driverId).getUniqueId();
-            drivers.remove(driverId);
+    @Override
+    public void removeItem(long driverId) throws SQLException {
+        Driver cachedDriver = (Driver) getById(driverId);
+        getDataManager().removeObject(cachedDriver.getClass(), driverId);
+        if (cachedDriver != null) {
+            String driverUniqueId = cachedDriver.getUniqueId();
+            removeCachedItem(driverId);
             driversByUniqueId.remove(driverUniqueId);
         }
-        refreshUserDrivers();
+        refreshUserItems();
         refresh();
     }
 
-    public boolean checkDriver(long userId, long driverId) {
-        return getUserDrivers(userId).contains(driverId);
-    }
-
-    public Driver getDriver(long id) {
-        return drivers.get(id);
-    }
-
     public Driver getDriverByUniqueId(String uniqueId) {
         return driversByUniqueId.get(uniqueId);
     }
-
-    public final Collection<Driver> getDrivers(Set<Long> driverIds) {
-        Collection<Driver> result = new LinkedList<>();
-        for (long driverId : driverIds) {
-            result.add(getDriver(driverId));
-        }
-        return result;
-    }
-
-    public final Set<Long> getAllDrivers() {
-        return drivers.keySet();
-    }
-
-    public final Set<Long> getManagedDrivers(long userId) {
-        Set<Long> drivers = new HashSet<>();
-        drivers.addAll(getUserDrivers(userId));
-        for (long managedUserId : Context.getPermissionsManager().getUserPermissions(userId)) {
-            drivers.addAll(getUserDrivers(managedUserId));
-        }
-        return drivers;
-    }
 }
diff --git a/src/org/traccar/database/ExtendedObjectManager.java b/src/org/traccar/database/ExtendedObjectManager.java
new file mode 100644
index 000000000..5147b9f9f
--- /dev/null
+++ b/src/org/traccar/database/ExtendedObjectManager.java
@@ -0,0 +1,129 @@
+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.database;
+
+import java.sql.SQLException;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.traccar.Context;
+import org.traccar.helper.Log;
+import org.traccar.model.BaseDevicePermission;
+import org.traccar.model.BaseGroupPermission;
+import org.traccar.model.BaseUserPermission;
+import org.traccar.model.Device;
+import org.traccar.model.Identifiable;
+
+public abstract class ExtendedObjectManager extends SimpleObjectManager {
+
+    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<>();
+
+    private Class<? extends BaseDevicePermission> devicePermissionClass;
+    private Class<? extends BaseGroupPermission> groupPermissionClass;
+
+    protected ExtendedObjectManager(DataManager dataManager,
+            Class<? extends Identifiable> baseClass,
+            Class<? extends BaseUserPermission> permissionClass,
+            Class<? extends BaseDevicePermission> devicePermissionClass,
+            Class<? extends BaseGroupPermission> groupPermissionClass) {
+        super(dataManager, baseClass, permissionClass);
+        this.devicePermissionClass = devicePermissionClass;
+        this.groupPermissionClass = groupPermissionClass;
+    }
+
+    public final Set<Long> getGroupItems(long groupId) {
+        if (!groupItems.containsKey(groupId)) {
+            groupItems.put(groupId, new HashSet<Long>());
+        }
+        return groupItems.get(groupId);
+    }
+
+    protected final void clearGroupItems() {
+        groupItems.clear();
+    }
+
+    public final Set<Long> getDeviceItems(long deviceId) {
+        if (!deviceItems.containsKey(deviceId)) {
+            deviceItems.put(deviceId, new HashSet<Long>());
+        }
+        return deviceItems.get(deviceId);
+    }
+
+    protected final void clearDeviceItems() {
+        deviceItems.clear();
+    }
+
+    public Set<Long> getAllDeviceItems(long deviceId) {
+        if (!deviceItemsWithGroups.containsKey(deviceId)) {
+            deviceItemsWithGroups.put(deviceId, new HashSet<Long>());
+        }
+        return deviceItemsWithGroups.get(deviceId);
+    }
+
+    @Override
+    public void removeItem(long itemId) throws SQLException {
+        super.removeItem(itemId);
+        refresh();
+    }
+
+    public void refresh() {
+        if (getDataManager() != null) {
+            try {
+
+                Collection<? extends BaseGroupPermission> databaseGroupPermissions =
+                        getDataManager().getObjects(groupPermissionClass);
+
+                clearGroupItems();
+                for (BaseGroupPermission groupPermission : databaseGroupPermissions) {
+                    getGroupItems(groupPermission.getGroupId()).add(groupPermission.getSlaveId());
+                }
+
+                Collection<? extends BaseDevicePermission> databaseDevicePermissions =
+                        getDataManager().getObjects(devicePermissionClass);
+                Collection<Device> allDevices = Context.getDeviceManager().getAllDevices();
+
+                clearDeviceItems();
+                deviceItemsWithGroups.clear();
+
+                for (BaseDevicePermission devicePermission : databaseDevicePermissions) {
+                    getDeviceItems(devicePermission.getDeviceId()).add(devicePermission.getSlaveId());
+                    getAllDeviceItems(devicePermission.getDeviceId()).add(devicePermission.getSlaveId());
+                }
+
+                for (Device device : allDevices) {
+                    long groupId = device.getGroupId();
+                    while (groupId != 0) {
+                        getAllDeviceItems(device.getId()).addAll(getGroupItems(groupId));
+                        if (Context.getDeviceManager().getGroupById(groupId) != null) {
+                            groupId = Context.getDeviceManager().getGroupById(groupId).getGroupId();
+                        } else {
+                            groupId = 0;
+                        }
+                    }
+                }
+
+            } catch (SQLException error) {
+                Log.warning(error);
+            }
+        }
+    }
+}
diff --git a/src/org/traccar/database/GeofenceManager.java b/src/org/traccar/database/GeofenceManager.java
index b8e6a5d73..868804d8f 100644
--- a/src/org/traccar/database/GeofenceManager.java
+++ b/src/org/traccar/database/GeofenceManager.java
@@ -15,20 +15,10 @@
  */
 package org.traccar.database;
 
-import java.sql.SQLException;
 import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.locks.ReadWriteLock;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import org.traccar.Context;
-import org.traccar.helper.Log;
 import org.traccar.model.Device;
 import org.traccar.model.DeviceGeofence;
 import org.traccar.model.Geofence;
@@ -36,269 +26,45 @@ import org.traccar.model.GeofencePermission;
 import org.traccar.model.GroupGeofence;
 import org.traccar.model.Position;
 
-public class GeofenceManager {
-
-    private final DataManager dataManager;
-
-    private final Map<Long, Geofence> geofences = new HashMap<>();
-    private final Map<Long, Set<Long>> userGeofences = new HashMap<>();
-    private final Map<Long, Set<Long>> groupGeofences = new HashMap<>();
-
-    private final Map<Long, Set<Long>> deviceGeofencesWithGroups = new HashMap<>();
-    private final Map<Long, Set<Long>> deviceGeofences = new HashMap<>();
-
-    private final ReadWriteLock deviceGeofencesLock = new ReentrantReadWriteLock();
-    private final ReadWriteLock geofencesLock = new ReentrantReadWriteLock();
-    private final ReadWriteLock groupGeofencesLock = new ReentrantReadWriteLock();
-    private final ReadWriteLock userGeofencesLock = new ReentrantReadWriteLock();
+public class GeofenceManager extends ExtendedObjectManager {
 
     public GeofenceManager(DataManager dataManager) {
-        this.dataManager = dataManager;
-        refreshGeofences();
-    }
-
-    private Set<Long> getUserGeofences(long userId) {
-        if (!userGeofences.containsKey(userId)) {
-            userGeofences.put(userId, new HashSet<Long>());
-        }
-        return userGeofences.get(userId);
-    }
-
-    public Set<Long> getUserGeofencesIds(long userId) {
-        userGeofencesLock.readLock().lock();
-        try {
-            return getUserGeofences(userId);
-        } finally {
-            userGeofencesLock.readLock().unlock();
-        }
-    }
-
-    private Set<Long> getGroupGeofences(long groupId) {
-        if (!groupGeofences.containsKey(groupId)) {
-            groupGeofences.put(groupId, new HashSet<Long>());
-        }
-        return groupGeofences.get(groupId);
-    }
-
-    public Set<Long> getGroupGeofencesIds(long groupId) {
-        groupGeofencesLock.readLock().lock();
-        try {
-            return getGroupGeofences(groupId);
-        } finally {
-            groupGeofencesLock.readLock().unlock();
-        }
-    }
-
-    public Set<Long> getAllDeviceGeofences(long deviceId) {
-        deviceGeofencesLock.readLock().lock();
-        try {
-            return getDeviceGeofences(deviceGeofencesWithGroups, deviceId);
-        } finally {
-            deviceGeofencesLock.readLock().unlock();
-        }
-    }
-
-    public Set<Long> getDeviceGeofencesIds(long deviceId) {
-        deviceGeofencesLock.readLock().lock();
-        try {
-            return getDeviceGeofences(deviceGeofences, deviceId);
-        } finally {
-            deviceGeofencesLock.readLock().unlock();
-        }
-    }
-
-    private Set<Long> getDeviceGeofences(Map<Long, Set<Long>> deviceGeofences, long deviceId) {
-        if (!deviceGeofences.containsKey(deviceId)) {
-            deviceGeofences.put(deviceId, new HashSet<Long>());
-        }
-        return deviceGeofences.get(deviceId);
-    }
-
-    public final void refreshGeofences() {
-        if (dataManager != null) {
-            try {
-                geofencesLock.writeLock().lock();
-                try {
-                    geofences.clear();
-                    for (Geofence geofence : dataManager.getGeofences()) {
-                        geofences.put(geofence.getId(), geofence);
-                    }
-                } finally {
-                    geofencesLock.writeLock().unlock();
-                }
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-        refreshUserGeofences();
+        super(dataManager, Geofence.class, GeofencePermission.class, DeviceGeofence.class, GroupGeofence.class);
+        refreshItems();
         refresh();
     }
 
-    public final void refreshUserGeofences() {
-        if (dataManager != null) {
-            try {
-                userGeofencesLock.writeLock().lock();
-                try {
-                    userGeofences.clear();
-                    for (GeofencePermission geofencePermission : dataManager.getGeofencePermissions()) {
-                        getUserGeofences(geofencePermission.getUserId()).add(geofencePermission.getGeofenceId());
-                    }
-                } finally {
-                    userGeofencesLock.writeLock().unlock();
-                }
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-    }
-
     public final void refresh() {
-        if (dataManager != null) {
-            try {
-
-                Collection<GroupGeofence> databaseGroupGeofences = dataManager.getGroupGeofences();
-                groupGeofencesLock.writeLock().lock();
-                try {
-                    groupGeofences.clear();
-                    for (GroupGeofence groupGeofence : databaseGroupGeofences) {
-                        getGroupGeofences(groupGeofence.getGroupId()).add(groupGeofence.getGeofenceId());
-                    }
-                } finally {
-                    groupGeofencesLock.writeLock().unlock();
-                }
-
-                Collection<DeviceGeofence> databaseDeviceGeofences = dataManager.getDeviceGeofences();
-                Collection<Device> allDevices = Context.getDeviceManager().getAllDevices();
-
-                groupGeofencesLock.readLock().lock();
-                deviceGeofencesLock.writeLock().lock();
-                try {
-                    deviceGeofences.clear();
-                    deviceGeofencesWithGroups.clear();
-
-                    for (DeviceGeofence deviceGeofence : databaseDeviceGeofences) {
-                        getDeviceGeofences(deviceGeofences, deviceGeofence.getDeviceId())
-                            .add(deviceGeofence.getGeofenceId());
-                        getDeviceGeofences(deviceGeofencesWithGroups, deviceGeofence.getDeviceId())
-                            .add(deviceGeofence.getGeofenceId());
-                    }
-
-                    for (Device device : allDevices) {
-                        long groupId = device.getGroupId();
-                        while (groupId != 0) {
-                            getDeviceGeofences(deviceGeofencesWithGroups,
-                                    device.getId()).addAll(getGroupGeofences(groupId));
-                            if (Context.getDeviceManager().getGroupById(groupId) != null) {
-                                groupId = Context.getDeviceManager().getGroupById(groupId).getGroupId();
-                            } else {
-                                groupId = 0;
-                            }
-                        }
-                        List<Long> deviceGeofenceIds = device.getGeofenceIds();
-                        if (deviceGeofenceIds == null) {
-                            deviceGeofenceIds = new ArrayList<>();
-                        } else {
-                            deviceGeofenceIds.clear();
-                        }
-                        Position lastPosition = Context.getIdentityManager().getLastPosition(device.getId());
-                        if (lastPosition != null && deviceGeofencesWithGroups.containsKey(device.getId())) {
-                            for (long geofenceId : deviceGeofencesWithGroups.get(device.getId())) {
-                                Geofence geofence = getGeofence(geofenceId);
-                                if (geofence != null && geofence.getGeometry()
-                                        .containsPoint(lastPosition.getLatitude(), lastPosition.getLongitude())) {
-                                    deviceGeofenceIds.add(geofenceId);
-                                }
-                            }
-                        }
-                        device.setGeofenceIds(deviceGeofenceIds);
-                    }
-
-                } finally {
-                    deviceGeofencesLock.writeLock().unlock();
-                    groupGeofencesLock.readLock().unlock();
-                }
-
-            } catch (SQLException error) {
-                Log.warning(error);
-            }
-        }
-    }
-
-    public final Collection<Geofence> getAllGeofences() {
-        geofencesLock.readLock().lock();
-        try {
-            return geofences.values();
-        } finally {
-            geofencesLock.readLock().unlock();
-        }
-    }
-
-    public final Set<Long> getAllGeofencesIds() {
-        geofencesLock.readLock().lock();
-        try {
-            return geofences.keySet();
-        } finally {
-            geofencesLock.readLock().unlock();
-        }
-    }
-
-    public final Set<Long> getManagedGeofencesIds(long userId) {
-        Set<Long> geofences = new HashSet<>();
-        geofences.addAll(getUserGeofencesIds(userId));
-        for (long managedUserId : Context.getPermissionsManager().getUserPermissions(userId)) {
-            geofences.addAll(getUserGeofencesIds(managedUserId));
-        }
-        return geofences;
-    }
-
-    public final Collection<Geofence> getGeofences(Set<Long> geofencesIds) {
-        geofencesLock.readLock().lock();
-        try {
-            Collection<Geofence> result = new LinkedList<>();
-            for (long geofenceId : geofencesIds) {
-                result.add(getGeofence(geofenceId));
-            }
-            return result;
-        } finally {
-            geofencesLock.readLock().unlock();
-        }
-    }
-
-    public final Geofence getGeofence(long geofenceId) {
-        geofencesLock.readLock().lock();
-        try {
-            return geofences.get(geofenceId);
-        } finally {
-            geofencesLock.readLock().unlock();
-        }
-    }
-
-    public final void updateGeofence(Geofence geofence) {
-        geofencesLock.writeLock().lock();
-        try {
-            geofences.put(geofence.getId(), geofence);
-        } finally {
-            geofencesLock.writeLock().unlock();
-        }
-        try {
-            dataManager.updateGeofence(geofence);
-        } catch (SQLException error) {
-            Log.warning(error);
-        }
-    }
-
-    public boolean checkGeofence(long userId, long geofenceId) {
-        return getUserGeofencesIds(userId).contains(geofenceId);
+        super.refresh();
+        recalculateDevicesGeofences();
     }
 
     public List<Long> getCurrentDeviceGeofences(Position position) {
         List<Long> result = new ArrayList<>();
-        for (long geofenceId : getAllDeviceGeofences(position.getDeviceId())) {
-            if (getGeofence(geofenceId).getGeometry().containsPoint(position.getLatitude(), position.getLongitude())) {
+        for (long geofenceId : getAllDeviceItems(position.getDeviceId())) {
+            Geofence geofence = (Geofence) getById(geofenceId);
+            if (geofence != null && geofence.getGeometry()
+                    .containsPoint(position.getLatitude(), position.getLongitude())) {
                 result.add(geofenceId);
             }
         }
         return result;
     }
 
+    public void recalculateDevicesGeofences() {
+        for (Device device : Context.getDeviceManager().getAllDevices()) {
+            List<Long> deviceGeofenceIds = device.getGeofenceIds();
+            if (deviceGeofenceIds == null) {
+                deviceGeofenceIds = new ArrayList<>();
+            } else {
+                deviceGeofenceIds.clear();
+            }
+            Position lastPosition = Context.getIdentityManager().getLastPosition(device.getId());
+            if (lastPosition != null && getAllDeviceItems(device.getId()) != null) {
+                deviceGeofenceIds.addAll(getCurrentDeviceGeofences(lastPosition));
+            }
+            device.setGeofenceIds(deviceGeofenceIds);
+        }
+    }
+
 }
diff --git a/src/org/traccar/database/NotificationManager.java b/src/org/traccar/database/NotificationManager.java
index 48caa615c..11d5a9aca 100644
--- a/src/org/traccar/database/NotificationManager.java
+++ b/src/org/traccar/database/NotificationManager.java
@@ -57,7 +57,7 @@ public class NotificationManager {
         Set<Long> users = Context.getPermissionsManager().getDeviceUsers(event.getDeviceId());
         for (long userId : users) {
             if (event.getGeofenceId() == 0 || Context.getGeofenceManager() != null
-                    && Context.getGeofenceManager().checkGeofence(userId, event.getGeofenceId())) {
+                    && Context.getGeofenceManager().checkItemPermission(userId, event.getGeofenceId())) {
                 Notification notification = getUserNotificationByType(userId, event.getType());
                 if (notification != null) {
                     if (notification.getWeb()) {
diff --git a/src/org/traccar/database/PermissionsManager.java b/src/org/traccar/database/PermissionsManager.java
index 82ca6af49..f88e14bfe 100644
--- a/src/org/traccar/database/PermissionsManager.java
+++ b/src/org/traccar/database/PermissionsManager.java
@@ -298,52 +298,37 @@ public class PermissionsManager {
         }
     }
 
-    public void checkGeofence(long userId, long geofenceId) throws SecurityException {
-        if (!Context.getGeofenceManager().checkGeofence(userId, geofenceId) && !isAdmin(userId)) {
-            checkManager(userId);
-            for (long managedUserId : getUserPermissions(userId)) {
-                if (Context.getGeofenceManager().checkGeofence(managedUserId, geofenceId)) {
-                    return;
-                }
-            }
-            throw new SecurityException("Geofence access denied");
-        }
-    }
-
-    public void checkAttribute(long userId, long attributeId) throws SecurityException {
-        if (!Context.getAttributesManager().checkAttribute(userId, attributeId) && !isAdmin(userId)) {
-            checkManager(userId);
-            for (long managedUserId : getUserPermissions(userId)) {
-                if (Context.getAttributesManager().checkAttribute(managedUserId, attributeId)) {
-                    return;
-                }
-            }
-            throw new SecurityException("Attribute access denied");
-        }
-    }
-
-    public void checkDriver(long userId, long driverId) throws SecurityException {
-        if (!Context.getDriversManager().checkDriver(userId, driverId) && !isAdmin(userId)) {
-            checkManager(userId);
-            for (long managedUserId : getUserPermissions(userId)) {
-                if (Context.getDriversManager().checkDriver(managedUserId, driverId)) {
-                    return;
-                }
-            }
-            throw new SecurityException("Driver access denied");
-        }
-    }
-
-
-    public void checkCalendar(long userId, long calendarId) throws SecurityException {
-        if (!Context.getCalendarManager().checkCalendar(userId, calendarId) && !isAdmin(userId)) {
-            checkManager(userId);
-            for (long managedUserId : getUserPermissions(userId)) {
-                if (Context.getCalendarManager().checkCalendar(managedUserId, calendarId)) {
-                    return;
+    public void checkPermission(String object, long userId, long objectId) throws SecurityException {
+        SimpleObjectManager manager = null;
+
+        switch (object) {
+            case "geofence":
+                manager = Context.getGeofenceManager();
+                break;
+            case "attribute":
+                manager = Context.getAttributesManager();
+                break;
+            case "driver":
+                manager = Context.getDriversManager();
+                break;
+            case "calendar":
+                manager = Context.getCalendarManager();
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown object type");
+        }
+
+        if (manager != null) {
+            if (manager.checkItemPermission(userId, objectId) && !isAdmin(userId)) {
+                checkManager(userId);
+                for (long managedUserId : getUserPermissions(userId)) {
+                    if (manager.checkItemPermission(managedUserId, objectId)) {
+                        return;
+                    }
                 }
+                throw new SecurityException(object.substring(0, 1).toUpperCase() + object.substring(1)
+                         + " access denied");
             }
-            throw new SecurityException("Calendar access denied");
         }
     }
 
diff --git a/src/org/traccar/database/SimpleObjectManager.java b/src/org/traccar/database/SimpleObjectManager.java
new file mode 100644
index 000000000..84d41a84f
--- /dev/null
+++ b/src/org/traccar/database/SimpleObjectManager.java
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.database;
+
+import java.sql.SQLException;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.traccar.Context;
+import org.traccar.helper.Log;
+import org.traccar.model.BaseUserPermission;
+import org.traccar.model.Identifiable;
+
+public abstract class SimpleObjectManager {
+
+    private final DataManager dataManager;
+
+    private final Map<Long, Identifiable> items = new ConcurrentHashMap<>();
+    private final Map<Long, Set<Long>> userItems = new ConcurrentHashMap<>();
+
+    private Class<? extends Identifiable> baseClass;
+    private Class<? extends BaseUserPermission> permissionClass;
+
+    protected SimpleObjectManager(DataManager dataManager,
+            Class<? extends Identifiable> baseClass,
+            Class<? extends BaseUserPermission> permissionClass) {
+        this.dataManager = dataManager;
+        this.baseClass = baseClass;
+        this.permissionClass = permissionClass;
+    }
+
+    protected final DataManager getDataManager() {
+        return dataManager;
+    }
+
+    protected final Class<? extends Identifiable> getBaseClass() {
+        return baseClass;
+    }
+
+    public final Identifiable getById(long itemId) {
+        return items.get(itemId);
+    }
+
+    protected final void clearItems() {
+        items.clear();
+    }
+
+    protected final void putItem(long itemId, Identifiable item) {
+        items.put(itemId, item);
+    }
+
+    protected final void removeCachedItem(long itemId) {
+        items.remove(itemId);
+    }
+
+    public final Set<Long> getUserItems(long userId) {
+        if (!userItems.containsKey(userId)) {
+            userItems.put(userId, new HashSet<Long>());
+        }
+        return userItems.get(userId);
+    }
+
+    protected final void clearUserItems() {
+        userItems.clear();
+    }
+
+    public final boolean checkItemPermission(long userId, long itemId) {
+        return getUserItems(userId).contains(itemId);
+    }
+
+    public void refreshItems() {
+        if (dataManager != null) {
+            try {
+                clearItems();
+                for (Identifiable item : dataManager.getObjects(this.baseClass)) {
+                    putItem(item.getId(), item);
+                }
+            } catch (SQLException error) {
+                Log.warning(error);
+            }
+        }
+        refreshUserItems();
+    }
+
+    public final void refreshUserItems() {
+        if (dataManager != null) {
+            try {
+                clearUserItems();
+                for (BaseUserPermission permission : dataManager.getObjects(this.permissionClass)) {
+                    getUserItems(permission.getUserId()).add(permission.getSlaveId());
+                }
+            } catch (SQLException error) {
+                Log.warning(error);
+            }
+        }
+    }
+
+    public void addItem(Identifiable item) throws SQLException {
+        dataManager.addObject(item);
+        putItem(item.getId(), item);
+    }
+
+    public void updateItem(Identifiable item) throws SQLException {
+        dataManager.updateObject(item);
+        putItem(item.getId(), item);
+    }
+
+    public void removeItem(long itemId) throws SQLException {
+        Identifiable item = getById(itemId);
+        if (item != null) {
+            dataManager.removeObject(item.getClass(), itemId);
+            removeCachedItem(itemId);
+        }
+        refreshUserItems();
+    }
+
+//    public final Collection<? extends Identifiable> getItems(Set<Long> itemIds) {
+//        Collection<Identifiable> result = new LinkedList<>();
+//        for (long itemId : itemIds) {
+//            result.add(getById(itemId));
+//        }
+//        return result;
+//    }
+
+    public final <T> Collection<T> getItems(Class<T> clazz, Set<Long> itemIds) {
+        Collection<T> result = new LinkedList<>();
+        for (long itemId : itemIds) {
+            result.add((T) getById(itemId));
+        }
+        return result;
+    }
+
+    public final Set<Long> getAllItems() {
+        return items.keySet();
+    }
+
+    public final Set<Long> getManagedItems(long userId) {
+        Set<Long> result = new HashSet<>();
+        result.addAll(getUserItems(userId));
+        for (long managedUserId : Context.getPermissionsManager().getUserPermissions(userId)) {
+            result.addAll(getUserItems(managedUserId));
+        }
+        return result;
+    }
+
+}
diff --git a/src/org/traccar/events/GeofenceEventHandler.java b/src/org/traccar/events/GeofenceEventHandler.java
index fbec932b1..cdac7993f 100644
--- a/src/org/traccar/events/GeofenceEventHandler.java
+++ b/src/org/traccar/events/GeofenceEventHandler.java
@@ -22,8 +22,10 @@ import java.util.List;
 import org.traccar.BaseEventHandler;
 import org.traccar.Context;
 import org.traccar.database.GeofenceManager;
+import org.traccar.model.Calendar;
 import org.traccar.model.Device;
 import org.traccar.model.Event;
+import org.traccar.model.Geofence;
 import org.traccar.model.Position;
 
 public class GeofenceEventHandler extends BaseEventHandler {
@@ -57,18 +59,20 @@ public class GeofenceEventHandler extends BaseEventHandler {
 
         Collection<Event> events = new ArrayList<>();
         for (long geofenceId : newGeofences) {
-            long calendarId = geofenceManager.getGeofence(geofenceId).getCalendarId();
-            if (calendarId == 0 || Context.getCalendarManager().getCalendar(calendarId) == null
-                    || Context.getCalendarManager().getCalendar(calendarId).checkMoment(position.getFixTime())) {
+            long calendarId = ((Geofence) geofenceManager.getById(geofenceId)).getCalendarId();
+            if (calendarId == 0 || Context.getCalendarManager().getById(calendarId) == null
+                    || ((Calendar) Context.getCalendarManager().getById(calendarId))
+                    .checkMoment(position.getFixTime())) {
                 Event event = new Event(Event.TYPE_GEOFENCE_ENTER, position.getDeviceId(), position.getId());
                 event.setGeofenceId(geofenceId);
                 events.add(event);
             }
         }
         for (long geofenceId : oldGeofences) {
-            long calendarId = geofenceManager.getGeofence(geofenceId).getCalendarId();
-            if (calendarId == 0 || Context.getCalendarManager().getCalendar(calendarId) == null
-                    || Context.getCalendarManager().getCalendar(calendarId).checkMoment(position.getFixTime())) {
+            long calendarId = ((Geofence) geofenceManager.getById(geofenceId)).getCalendarId();
+            if (calendarId == 0 || Context.getCalendarManager().getById(calendarId) == null
+                    || ((Calendar) Context.getCalendarManager().getById(calendarId))
+                    .checkMoment(position.getFixTime())) {
                 Event event = new Event(Event.TYPE_GEOFENCE_EXIT, position.getDeviceId(), position.getId());
                 event.setGeofenceId(geofenceId);
                 events.add(event);
diff --git a/src/org/traccar/model/Attribute.java b/src/org/traccar/model/Attribute.java
index 9c3b5e43b..ab12cd2c4 100644
--- a/src/org/traccar/model/Attribute.java
+++ b/src/org/traccar/model/Attribute.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class Attribute {
-
-    private long id;
-
-    public long getId() {
-        return id;
-    }
-
-    public void setId(long id) {
-        this.id = id;
-    }
+public class Attribute extends Identifiable {
 
     private String description;
 
diff --git a/src/org/traccar/model/AttributeAlias.java b/src/org/traccar/model/AttributeAlias.java
index 2835c0558..5aa8a5122 100644
--- a/src/org/traccar/model/AttributeAlias.java
+++ b/src/org/traccar/model/AttributeAlias.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class AttributeAlias {
-
-    private long id;
-
-    public long getId() {
-        return id;
-    }
-
-    public void setId(long id) {
-        this.id = id;
-    }
+public class AttributeAlias extends Identifiable {
 
     private long deviceId;
 
diff --git a/src/org/traccar/model/AttributePermission.java b/src/org/traccar/model/AttributePermission.java
index fe2fe7b6e..e6bbb0f91 100644
--- a/src/org/traccar/model/AttributePermission.java
+++ b/src/org/traccar/model/AttributePermission.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class AttributePermission {
-
-    private long userId;
-
-    public long getUserId() {
-        return userId;
-    }
-
-    public void setUserId(long userId) {
-        this.userId = userId;
-    }
+public class AttributePermission extends BaseUserPermission {
 
     private long attributeId;
 
@@ -38,4 +28,9 @@ public class AttributePermission {
         this.attributeId = attributeId;
     }
 
+    @Override
+    public long getSlaveId() {
+        return attributeId;
+    }
+
 }
diff --git a/src/org/traccar/model/BaseDevicePermission.java b/src/org/traccar/model/BaseDevicePermission.java
new file mode 100644
index 000000000..6eda15d0e
--- /dev/null
+++ b/src/org/traccar/model/BaseDevicePermission.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.model;
+
+public abstract class BaseDevicePermission implements BasePermission {
+
+    private long deviceId;
+
+    public long getDeviceId() {
+        return deviceId;
+    }
+
+    public void setDeviceId(long deviceId) {
+        this.deviceId = deviceId;
+    }
+
+}
diff --git a/src/org/traccar/model/BaseGroupPermission.java b/src/org/traccar/model/BaseGroupPermission.java
new file mode 100644
index 000000000..5a289cad2
--- /dev/null
+++ b/src/org/traccar/model/BaseGroupPermission.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.model;
+
+public abstract class BaseGroupPermission implements BasePermission {
+
+    private long groupId;
+
+    public long getGroupId() {
+        return groupId;
+    }
+
+    public void setGroupId(long groupId) {
+        this.groupId = groupId;
+    }
+
+}
diff --git a/src/org/traccar/model/BasePermission.java b/src/org/traccar/model/BasePermission.java
new file mode 100644
index 000000000..6f1baffdc
--- /dev/null
+++ b/src/org/traccar/model/BasePermission.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.model;
+
+public interface BasePermission {
+
+    long getSlaveId();
+
+}
diff --git a/src/org/traccar/model/BaseUserPermission.java b/src/org/traccar/model/BaseUserPermission.java
new file mode 100644
index 000000000..64a7be82a
--- /dev/null
+++ b/src/org/traccar/model/BaseUserPermission.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.model;
+
+public abstract class BaseUserPermission implements BasePermission {
+
+    private long userId;
+
+    public long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(long userId) {
+        this.userId = userId;
+    }
+
+}
diff --git a/src/org/traccar/model/CalendarPermission.java b/src/org/traccar/model/CalendarPermission.java
index 59f54e07b..d95e51b0e 100644
--- a/src/org/traccar/model/CalendarPermission.java
+++ b/src/org/traccar/model/CalendarPermission.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class CalendarPermission {
-
-    private long userId;
-
-    public long getUserId() {
-        return userId;
-    }
-
-    public void setUserId(long userId) {
-        this.userId = userId;
-    }
+public class CalendarPermission extends BaseUserPermission {
 
     private long calendarId;
 
@@ -37,4 +27,9 @@ public class CalendarPermission {
     public void setCalendarId(long calendarId) {
         this.calendarId = calendarId;
     }
+
+    @Override
+    public long getSlaveId() {
+        return calendarId;
+    }
 }
diff --git a/src/org/traccar/model/DeviceAttribute.java b/src/org/traccar/model/DeviceAttribute.java
index e0ac6dd98..bfcd873fa 100644
--- a/src/org/traccar/model/DeviceAttribute.java
+++ b/src/org/traccar/model/DeviceAttribute.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class DeviceAttribute {
-
-    private long deviceId;
-
-    public long getDeviceId() {
-        return deviceId;
-    }
-
-    public void setDeviceId(long deviceId) {
-        this.deviceId = deviceId;
-    }
+public class DeviceAttribute extends BaseDevicePermission {
 
     private long attributeId;
 
@@ -37,4 +27,9 @@ public class DeviceAttribute {
     public void setAttributeId(long attributeId) {
         this.attributeId = attributeId;
     }
+
+    @Override
+    public long getSlaveId() {
+        return attributeId;
+    }
 }
diff --git a/src/org/traccar/model/DeviceDriver.java b/src/org/traccar/model/DeviceDriver.java
index 2008aaddf..f5257531d 100644
--- a/src/org/traccar/model/DeviceDriver.java
+++ b/src/org/traccar/model/DeviceDriver.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class DeviceDriver {
-
-    private long deviceId;
-
-    public long getDeviceId() {
-        return deviceId;
-    }
-
-    public void setDeviceId(long deviceId) {
-        this.deviceId = deviceId;
-    }
+public class DeviceDriver extends BaseDevicePermission {
 
     private long driverId;
 
@@ -38,4 +28,9 @@ public class DeviceDriver {
         this.driverId = driverId;
     }
 
+    @Override
+    public long getSlaveId() {
+        return driverId;
+    }
+
 }
diff --git a/src/org/traccar/model/DeviceGeofence.java b/src/org/traccar/model/DeviceGeofence.java
index 00c99add6..7ea4d3bea 100644
--- a/src/org/traccar/model/DeviceGeofence.java
+++ b/src/org/traccar/model/DeviceGeofence.java
@@ -15,17 +15,7 @@
  */
 package org.traccar.model;
 
-public class DeviceGeofence {
-
-    private long deviceId;
-
-    public long getDeviceId() {
-        return deviceId;
-    }
-
-    public void setDeviceId(long deviceId) {
-        this.deviceId = deviceId;
-    }
+public class DeviceGeofence extends BaseDevicePermission {
 
     private long geofenceId;
 
@@ -37,4 +27,9 @@ public class DeviceGeofence {
         this.geofenceId = geofenceId;
     }
 
+    @Override
+    public long getSlaveId() {
+        return geofenceId;
+    }
+
 }
diff --git a/src/org/traccar/model/DriverPermission.java b/src/org/traccar/model/DriverPermission.java
index cdbcc4a50..44f34c8e6 100644
--- a/src/org/traccar/model/DriverPermission.java
+++ b/src/org/traccar/model/DriverPermission.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class DriverPermission {
-
-    private long userId;
-
-    public long getUserId() {
-        return userId;
-    }
-
-    public void setUserId(long userId) {
-        this.userId = userId;
-    }
+public class DriverPermission extends BaseUserPermission {
 
     private long driverId;
 
@@ -37,4 +27,9 @@ public class DriverPermission {
     public void setDriverId(long driverId) {
         this.driverId = driverId;
     }
+
+    @Override
+    public long getSlaveId() {
+        return driverId;
+    }
 }
diff --git a/src/org/traccar/model/Extensible.java b/src/org/traccar/model/Extensible.java
index b7953d8a6..3b382838e 100644
--- a/src/org/traccar/model/Extensible.java
+++ b/src/org/traccar/model/Extensible.java
@@ -18,17 +18,7 @@ package org.traccar.model;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
-public class Extensible {
-
-    private long id;
-
-    public long getId() {
-        return id;
-    }
-
-    public void setId(long id) {
-        this.id = id;
-    }
+public class Extensible extends Identifiable {
 
     private Map<String, Object> attributes = new LinkedHashMap<>();
 
diff --git a/src/org/traccar/model/GeofencePermission.java b/src/org/traccar/model/GeofencePermission.java
index 464f4e9eb..8606cc3e7 100644
--- a/src/org/traccar/model/GeofencePermission.java
+++ b/src/org/traccar/model/GeofencePermission.java
@@ -15,17 +15,7 @@
  */
 package org.traccar.model;
 
-public class GeofencePermission {
-
-    private long userId;
-
-    public long getUserId() {
-        return userId;
-    }
-
-    public void setUserId(long userId) {
-        this.userId = userId;
-    }
+public class GeofencePermission extends BaseUserPermission {
 
     private long geofenceId;
 
@@ -37,4 +27,9 @@ public class GeofencePermission {
         this.geofenceId = geofenceId;
     }
 
+    @Override
+    public long getSlaveId() {
+        return geofenceId;
+    }
+
 }
diff --git a/src/org/traccar/model/GroupAttribute.java b/src/org/traccar/model/GroupAttribute.java
index a7e8a80bc..cfaf9cc2f 100644
--- a/src/org/traccar/model/GroupAttribute.java
+++ b/src/org/traccar/model/GroupAttribute.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class GroupAttribute {
-
-    private long groupId;
-
-    public long getGroupId() {
-        return groupId;
-    }
-
-    public void setGroupId(long groupId) {
-        this.groupId = groupId;
-    }
+public class GroupAttribute extends BaseGroupPermission {
 
     private long attributeId;
 
@@ -37,4 +27,9 @@ public class GroupAttribute {
     public void setAttributeId(long attributeId) {
         this.attributeId = attributeId;
     }
+
+    @Override
+    public long getSlaveId() {
+        return attributeId;
+    }
 }
diff --git a/src/org/traccar/model/GroupDriver.java b/src/org/traccar/model/GroupDriver.java
index 91b205923..9bf74c214 100644
--- a/src/org/traccar/model/GroupDriver.java
+++ b/src/org/traccar/model/GroupDriver.java
@@ -16,17 +16,7 @@
  */
 package org.traccar.model;
 
-public class GroupDriver {
-
-    private long groupId;
-
-    public long getGroupId() {
-        return groupId;
-    }
-
-    public void setGroupId(long groupId) {
-        this.groupId = groupId;
-    }
+public class GroupDriver extends BaseGroupPermission {
 
     private long driverId;
 
@@ -38,4 +28,9 @@ public class GroupDriver {
         this.driverId = driverId;
     }
 
+    @Override
+    public long getSlaveId() {
+        return driverId;
+    }
+
 }
diff --git a/src/org/traccar/model/GroupGeofence.java b/src/org/traccar/model/GroupGeofence.java
index 736e6c704..89830324d 100644
--- a/src/org/traccar/model/GroupGeofence.java
+++ b/src/org/traccar/model/GroupGeofence.java
@@ -15,17 +15,7 @@
  */
 package org.traccar.model;
 
-public class GroupGeofence {
-
-    private long groupId;
-
-    public long getGroupId() {
-        return groupId;
-    }
-
-    public void setGroupId(long groupId) {
-        this.groupId = groupId;
-    }
+public class GroupGeofence extends BaseGroupPermission {
 
     private long geofenceId;
 
@@ -37,4 +27,9 @@ public class GroupGeofence {
         this.geofenceId = geofenceId;
     }
 
+    @Override
+    public long getSlaveId() {
+        return geofenceId;
+    }
+
 }
diff --git a/src/org/traccar/model/Identifiable.java b/src/org/traccar/model/Identifiable.java
new file mode 100644
index 000000000..f22cfe800
--- /dev/null
+++ b/src/org/traccar/model/Identifiable.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2017 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.model;
+
+public class Identifiable {
+
+    private long id;
+
+    public final long getId() {
+        return id;
+    }
+
+    public final void setId(long id) {
+        this.id = id;
+    }
+
+}
diff --git a/src/org/traccar/notification/EventForwarder.java b/src/org/traccar/notification/EventForwarder.java
index bd7cfc0c5..08f55df75 100644
--- a/src/org/traccar/notification/EventForwarder.java
+++ b/src/org/traccar/notification/EventForwarder.java
@@ -75,7 +75,7 @@ public final class EventForwarder {
             }
         }
         if (event.getGeofenceId() != 0) {
-            Geofence geofence = Context.getGeofenceManager().getGeofence(event.getGeofenceId());
+            Geofence geofence = (Geofence) Context.getGeofenceManager().getById(event.getGeofenceId());
             if (geofence != null) {
                 data.put(KEY_GEOFENCE, geofence);
             }
diff --git a/src/org/traccar/notification/NotificationFormatter.java b/src/org/traccar/notification/NotificationFormatter.java
index a30023fdc..cd9959671 100644
--- a/src/org/traccar/notification/NotificationFormatter.java
+++ b/src/org/traccar/notification/NotificationFormatter.java
@@ -51,7 +51,7 @@ public final class NotificationFormatter {
             velocityContext.put("speedUnits", ReportUtils.getSpeedUnit(userId));
         }
         if (event.getGeofenceId() != 0) {
-            velocityContext.put("geofence", Context.getGeofenceManager().getGeofence(event.getGeofenceId()));
+            velocityContext.put("geofence", Context.getGeofenceManager().getById(event.getGeofenceId()));
         }
         String driverUniqueId = event.getString(Position.KEY_DRIVER_UNIQUE_ID);
         if (driverUniqueId != null) {
diff --git a/src/org/traccar/processing/ComputedAttributesHandler.java b/src/org/traccar/processing/ComputedAttributesHandler.java
index 536e39ec4..d6a762535 100644
--- a/src/org/traccar/processing/ComputedAttributesHandler.java
+++ b/src/org/traccar/processing/ComputedAttributesHandler.java
@@ -86,8 +86,8 @@ public class ComputedAttributesHandler extends BaseDataHandler {
 
     @Override
     protected Position handlePosition(Position position) {
-        Collection<Attribute> attributes = Context.getAttributesManager().getAttributes(
-                Context.getAttributesManager().getAllDeviceAttributes(position.getDeviceId()));
+        Collection<Attribute> attributes = Context.getAttributesManager().getItems(Attribute.class,
+                Context.getAttributesManager().getAllDeviceItems(position.getDeviceId()));
         for (Attribute attribute : attributes) {
             if (attribute.getAttribute() != null) {
                 Object result = null;
diff --git a/src/org/traccar/reports/Events.java b/src/org/traccar/reports/Events.java
index 0706f1382..3a111944c 100644
--- a/src/org/traccar/reports/Events.java
+++ b/src/org/traccar/reports/Events.java
@@ -50,7 +50,7 @@ public final class Events {
             for (Event event : events) {
                 if (all || types.contains(event.getType())) {
                     long geofenceId = event.getGeofenceId();
-                    if (geofenceId == 0 || Context.getGeofenceManager().checkGeofence(userId, geofenceId)) {
+                    if (geofenceId == 0 || Context.getGeofenceManager().checkItemPermission(userId, geofenceId)) {
                        result.add(event);
                     }
                 }
@@ -74,8 +74,8 @@ public final class Events {
                 if (all || types.contains(event.getType())) {
                     long geofenceId = event.getGeofenceId();
                     if (geofenceId != 0) {
-                        if (Context.getGeofenceManager().checkGeofence(userId, geofenceId)) {
-                            Geofence geofence = Context.getGeofenceManager().getGeofence(geofenceId);
+                        if (Context.getGeofenceManager().checkItemPermission(userId, geofenceId)) {
+                            Geofence geofence = (Geofence) Context.getGeofenceManager().getById(geofenceId);
                             if (geofence != null) {
                                 geofenceNames.put(geofenceId, geofence.getName());
                             }