making error messages more meaningful

components/mobile-plugins/android-plugin/org.wso2.carbon.device.mgt.mobile.android.api/src/main/java/org/wso2/carbon/mdm/services/android/bean/wrapper/FileTransferBeanWrapper.java

@@ -30,7 +30,7 @@ import java.util.List;
         description = "FileTransfer related Information.")
 public class FileTransferBeanWrapper {
 
-    @ApiModelProperty(name = "deviceIDs", value = "Device id list of the operation to be executed.", required = true)
+    @ApiModelProperty(name = "deviceIDs", value = "Device id list to which the operation to be executed.", required = true)
     private List<String> deviceIDs;
 
     @ApiModelProperty(name = "operation", value = "Information of the File Transfer Operation.", required = true)

components/mobile-plugins/android-plugin/org.wso2.carbon.device.mgt.mobile.android.api/src/main/java/org/wso2/carbon/mdm/services/android/services/DeviceManagementAdminService.java

@@ -232,7 +232,6 @@ public interface DeviceManagementAdminService {
     @ApiOperation(
             consumes = MediaType.APPLICATION_JSON,
             httpMethod = "POST",
-            //todo
             value = "Transferring file to the device.",
             notes = "Using this API you have the option to transfer a file from FTP server to an Android device.",
             response = Activity.class,

components/mobile-plugins/android-plugin/org.wso2.carbon.device.mgt.mobile.android.api/src/main/java/org/wso2/carbon/mdm/services/android/services/impl/DeviceManagementAdminServiceImpl.java

@@ -95,12 +95,12 @@ public class DeviceManagementAdminServiceImpl implements DeviceManagementAdminSe
     @Override
     public Response fileTransfer(FileTransferBeanWrapper fileTransferBeanWrapper) {
         if (log.isDebugEnabled()) {
-            log.debug("Invoking Android file transfer operation");
+            log.debug("Invoking Android file transfer operation for " + fileTransferBeanWrapper.getDeviceIDs());
         }
 
         try {
             if (fileTransferBeanWrapper == null || fileTransferBeanWrapper.getOperation() == null) {
-                String errorMessage = "Lock bean is empty.";
+                String errorMessage = "The payload of the file transfer operation is incorrect.";
                 log.error(errorMessage);
                 throw new BadRequestException(
                         new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage(errorMessage).build());
@@ -113,17 +113,17 @@ public class DeviceManagementAdminServiceImpl implements DeviceManagementAdminSe
             operation.setPayLoad(file.toJSON());
             return AndroidAPIUtils.getOperationResponse(fileTransferBeanWrapper.getDeviceIDs(), operation);
         } catch (InvalidDeviceException e) {
-            String errorMessage = "Invalid Device Identifiers found.";
+            String errorMessage = "Invalid Device Identifiers ( " + fileTransferBeanWrapper.getDeviceIDs() + " ) found.";
             log.error(errorMessage, e);
             throw new BadRequestException(
                     new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage(errorMessage).build());
         } catch (OperationManagementException e) {
-            String errorMessage = "Issue in retrieving operation management service instance";
+            String errorMessage = "Issue in retrieving operation management service instance for file transfer operation";
             log.error(errorMessage, e);
             throw new UnexpectedServerErrorException(
                     new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(errorMessage).build());
         } catch (DeviceManagementException e) {
-            String errorMessage = "Issue in retrieving device management service instance";
+            String errorMessage = "Issue in retrieving device management service instance for file transfer operation";
             log.error(errorMessage, e);
             throw new UnexpectedServerErrorException(
                     new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(errorMessage).build());