Code refactoring of device-status-task which Resolves harshanl/product-iots#518

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/status/task/impl/DeviceStatusMonitoringTask.java

@@ -43,7 +43,7 @@ import java.util.Map;
  */
 public class DeviceStatusMonitoringTask implements Task {
 
-    private static Log log = LogFactory.getLog(DeviceStatusMonitoringTask.class);
+    private static final Log log = LogFactory.getLog(DeviceStatusMonitoringTask.class);
     private String deviceType;
     private DeviceStatusTaskPluginConfig deviceStatusTaskPluginConfig;
     private int deviceTypeId = -1;
@@ -70,7 +70,7 @@ public class DeviceStatusMonitoringTask implements Task {
         EnrolmentInfo enrolmentInfo;
         try {
             operationEnrolmentMappings = this.getOperationEnrolmentMappings();
-            if (operationEnrolmentMappings.size() > 0) {
+            if (operationEnrolmentMappings != null && operationEnrolmentMappings.size() > 0) {
                 lastActivities = this.getLastDeviceActivities();
             }
         } catch (DeviceStatusTaskException e) {
@@ -78,7 +78,7 @@ public class DeviceStatusMonitoringTask implements Task {
         }
         for (OperationEnrolmentMapping mapping:operationEnrolmentMappings) {
             long lastActivity = -1;
-            if (lastActivities.containsKey(mapping.getEnrolmentId())) {
+            if (lastActivities != null && lastActivities.containsKey(mapping.getEnrolmentId())) {
                 lastActivity = lastActivities.get(mapping.getEnrolmentId());
             }
             EnrolmentInfo.Status newStatus = this.determineDeviceStatus(mapping, lastActivity);

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/status/task/impl/DeviceStatusTaskManagerServiceImpl.java

@@ -39,13 +39,13 @@ import java.util.Map;
  */
 public class DeviceStatusTaskManagerServiceImpl implements DeviceStatusTaskManagerService {
 
-    private static Log log = LogFactory.getLog(DeviceStatusTaskManagerServiceImpl.class);
+    private static final Log log = LogFactory.getLog(DeviceStatusTaskManagerServiceImpl.class);
 
     public static final String DEVICE_STATUS_MONITORING_TASK_TYPE = "DEVICE_STATUS_MONITORING";
     static final String DEVICE_TYPE = "DEVICE_TYPE";
     static final String DEVICE_TYPE_ID = "DEVICE_TYPE_ID";
     static final String DEVICE_STATUS_TASK_CONFIG = "DEVICE_STATUS_TASK_CONFIG";
-    private static String TASK_CLASS = DeviceStatusMonitoringTask.class.getName();
+    private static final String TASK_CLASS = DeviceStatusMonitoringTask.class.getName();
 
     @Override
     public void startTask(DeviceType deviceType, DeviceStatusTaskPluginConfig deviceStatusTaskConfig)