Code cleanup

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/api/DeviceManagementService.java

@@ -87,7 +87,7 @@ public interface DeviceManagementService {
                     message = "Not Acceptable.\n The requested media type is not supported"),
             @ApiResponse(
                     code = 500,
-                    message = "Internal Server ErrorResponse. \n Server error occurred while fetching the device list.",
+                    message = "Internal Server Error. \n Server error occurred while fetching the device list.",
                     response = ErrorResponse.class)
     })
     @Permission(scope = "device-list", permissions = {"/permission/admin/device-mgt/admin/devices/list"})
@@ -180,7 +180,7 @@ public interface DeviceManagementService {
                             response = ErrorResponse.class),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while retrieving information requested device.",
                             response = ErrorResponse.class)
             })
@@ -259,7 +259,7 @@ public interface DeviceManagementService {
                             message = "Not Acceptable. \n The requested media type is not supported."),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while retrieving feature list of the device.",
                             response = ErrorResponse.class)
             })
@@ -331,7 +331,7 @@ public interface DeviceManagementService {
                             message = "Unsupported media type. \n The entity of the request was in a not supported format."),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while enrolling the device.",
                             response = ErrorResponse.class)
             })
@@ -405,7 +405,7 @@ public interface DeviceManagementService {
                             message = "Not Acceptable. \n The requested media type is not supported."),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while retrieving installed application list of the device.",
                             response = ErrorResponse.class)
             })
@@ -494,7 +494,7 @@ public interface DeviceManagementService {
                             message = "Not Acceptable. \n The requested media type is not supported."),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while retrieving operation list scheduled for the device.",
                             response = ErrorResponse.class)
             })
@@ -582,7 +582,7 @@ public interface DeviceManagementService {
                             message = "Not Acceptable. \n The requested media type is not supported."),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while retrieving the effective policy calculated for the device.",
                             response = ErrorResponse.class)
             })

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/api/NotificationManagementService.java

@@ -85,7 +85,8 @@ public interface NotificationManagementService {
                             message = "Not Acceptable.\n The requested media type is not supported"),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n Server error occurred while fetching the notification list.",
+                            message = "Internal Server Error. " +
+                                    "\n Server error occurred while fetching the notification list.",
                             response = ErrorResponse.class)
             })
     @Permission(scope = "device-notification-view", permissions = {

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/api/PolicyManagementService.java

@@ -90,7 +90,7 @@ public interface PolicyManagementService {
                             message = "Unsupported media type. \n The entity of the request was in a not supported format."),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while adding a new policy.",
                             response = ErrorResponse.class)
             })
@@ -142,7 +142,7 @@ public interface PolicyManagementService {
                             message = "Not Acceptable.\n The requested media type is not supported"),
                     @ApiResponse(
                             code = 500,
-                            message = ("Internal Server ErrorResponse. \n Server error occurred while fetching " +
+                            message = ("Internal Server Error. \n Server error occurred while fetching " +
                                     "policies."),
                             response = ErrorResponse.class)
             })
@@ -205,7 +205,7 @@ public interface PolicyManagementService {
                             message = "Not Acceptable.\n The requested media type is not supported"),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n Server error occurred while fetching the " +
+                            message = "Internal Server Error. \n Server error occurred while fetching the " +
                                     "policy.",
                             response = ErrorResponse.class)
             })
@@ -265,7 +265,7 @@ public interface PolicyManagementService {
                             message = "Unsupported media type. \n The entity of the request was in a not supported format."),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while updating the policy.",
                             response = ErrorResponse.class)
             })
@@ -307,7 +307,7 @@ public interface PolicyManagementService {
                             message = "Unsupported media type. \n The entity of the request was in a not supported format."),
                     @ApiResponse(
                             code = 500,
-                            message = "Internal Server ErrorResponse. \n " +
+                            message = "Internal Server Error. \n " +
                                     "Server error occurred while bulk removing policies.",
                             response = ErrorResponse.class)
             })

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/api/admin/ApplicationManagementAdminService.java

@@ -68,7 +68,7 @@ public interface ApplicationManagementAdminService {
                     message = "Unsupported media type. \n The entity of the request was in a not supported format."),
             @ApiResponse(
                     code = 500,
-                    message = "Internal Server ErrorResponse. \n " +
+                    message = "Internal Server Error. \n " +
                             "Server error occurred while bulk issuing application installation operations upon " +
                             "a given set of devices.",
                     response = ErrorResponse.class)
@@ -106,7 +106,7 @@ public interface ApplicationManagementAdminService {
                     message = "Unsupported media type. \n The entity of the request was in a not supported format."),
             @ApiResponse(
                     code = 500,
-                    message = "Internal Server ErrorResponse. \n " +
+                    message = "Internal Server Error. \n " +
                             "Server error occurred while bulk issuing application un-installation operations upon " +
                             "a given set of devices.",
                     response = ErrorResponse.class)

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/api/admin/DeviceManagementAdminService.java

@@ -80,7 +80,7 @@ public interface DeviceManagementAdminService {
                     message = "Not Acceptable.\n The requested media type is not supported"),
             @ApiResponse(
                     code = 500,
-                    message = "Internal Server ErrorResponse. \n Server error occurred while fetching the device list.",
+                    message = "Internal Server Error. \n Server error occurred while fetching the device list.",
                     response = ErrorResponse.class)
     })
     Response getDevicesByName(

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/api/admin/UserManagementAdminService.java

@@ -60,7 +60,7 @@ public interface UserManagementAdminService {
                     message = "Unsupported media type. \n The entity of the request was in a not supported format."),
             @ApiResponse(
                     code = 500,
-                    message = "Internal Server ErrorResponse. \n " +
+                    message = "Internal Server Error. \n " +
                             "Server error occurred while updating credentials of the user.",
                     response = ErrorResponse.class)
     })

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/DeviceManagementServiceImpl.java

@@ -265,7 +265,7 @@ public class DeviceManagementServiceImpl implements DeviceManagementService {
             RequestValidationUtil.validateDeviceIdentifier(type, id);
 
             dms = DeviceMgtAPIUtils.getDeviceManagementService();
-            result = dms.getOperations(new DeviceIdentifier(id, type),request);
+            result = dms.getOperations(new DeviceIdentifier(id, type), request);
 
             operationsList.setList((List<? extends Operation>) result.getData());
             operationsList.setCount(result.getRecordsTotal());

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/NotificationManagementServiceImpl.java

@@ -22,11 +22,10 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.wso2.carbon.device.mgt.common.notification.mgt.Notification;
 import org.wso2.carbon.device.mgt.common.notification.mgt.NotificationManagementException;
-import org.wso2.carbon.device.mgt.jaxrs.NotificationContext;
 import org.wso2.carbon.device.mgt.jaxrs.beans.ErrorResponse;
+import org.wso2.carbon.device.mgt.jaxrs.beans.NotificationList;
 import org.wso2.carbon.device.mgt.jaxrs.service.api.NotificationManagementService;
-import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.*;
-import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.NotFoundException;
+import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.RequestValidationUtil;
 import org.wso2.carbon.device.mgt.jaxrs.util.DeviceMgtAPIUtils;
 
 import javax.ws.rs.*;
@@ -49,6 +48,7 @@ public class NotificationManagementServiceImpl implements NotificationManagement
             @QueryParam("offset") int offset, @QueryParam("limit") int limit) {
         String msg;
         List<Notification> notifications;
+        NotificationList notificationList = new NotificationList();
         try {
             if (status != null) {
                 RequestValidationUtil.validateNotificationStatus(status);
@@ -59,17 +59,14 @@ public class NotificationManagementServiceImpl implements NotificationManagement
                 notifications = DeviceMgtAPIUtils.getNotificationManagementService().getAllNotifications();
             }
 
-            if (notifications == null || notifications.size() == 0) {
-                throw new NotFoundException(
-                        new ErrorResponse.ErrorResponseBuilder().setCode(404l).setMessage("No notification is " +
-                                "available to be retrieved.").build());
-            }
-            return Response.status(Response.Status.OK).entity(notifications).build();
+            notificationList.setCount(notifications.size());
+            notificationList.setNotifications(notifications);
+            return Response.status(Response.Status.OK).entity(notificationList).build();
         } catch (NotificationManagementException e) {
-            msg = "Error occurred while retrieving notification info";
+            msg = "Error occurred while retrieving notification list";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         }
     }
 

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/PolicyManagementServiceImpl.java

@@ -298,7 +298,7 @@ public class PolicyManagementServiceImpl implements PolicyManagementService {
         }
         if (isPolicyDeActivated) {
             return Response.status(Response.Status.OK).entity("Selected policies have been successfully " +
-                                                                      "deactivated").build();
+                    "deactivated").build();
         } else {
             return Response.status(Response.Status.NOT_FOUND).entity(
                     new ErrorResponse.ErrorResponseBuilder().setMessage("Selected policies have " +

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/RoleManagementServiceImpl.java

@@ -209,7 +209,7 @@ public class RoleManagementServiceImpl implements RoleManagementService {
             //TODO fix what's returned in the entity
             return Response.created(new URI(API_BASE_PATH + "/" + roleInfo.getRoleName())).entity(
                     "Role '" + roleInfo.getRoleName() + "' has " +
-                    "successfully been added").build();
+                            "successfully been added").build();
         } catch (UserStoreException e) {
             String msg = "Error occurred while adding role '" + roleInfo.getRoleName() + "'";
             log.error(msg, e);

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/UserManagementServiceImpl.java

@@ -110,7 +110,7 @@ public class UserManagementServiceImpl implements UserManagementService {
                 }
                 return Response.status(Response.Status.NOT_FOUND).entity(
                         new ErrorResponse.ErrorResponseBuilder().setMessage(
-                        "User doesn't exist.").build()).build();
+                                "User doesn't exist.").build()).build();
             }
 
             BasicUserInfo user = this.getBasicUserInfo(username);

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/admin/ApplicationManagementAdminServiceImpl.java

@@ -29,9 +29,7 @@ import org.wso2.carbon.device.mgt.common.operation.mgt.Operation;
 import org.wso2.carbon.device.mgt.jaxrs.beans.ErrorResponse;
 import org.wso2.carbon.device.mgt.jaxrs.exception.UnknownApplicationTypeException;
 import org.wso2.carbon.device.mgt.jaxrs.service.api.admin.ApplicationManagementAdminService;
-import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.InputValidationException;
 import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.RequestValidationUtil;
-import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.UnexpectedServerErrorException;
 import org.wso2.carbon.device.mgt.jaxrs.util.DeviceMgtAPIUtils;
 import org.wso2.carbon.device.mgt.jaxrs.util.MDMAndroidOperationUtil;
 import org.wso2.carbon.device.mgt.jaxrs.util.MDMIOSOperationUtil;
@@ -82,21 +80,22 @@ public class ApplicationManagementAdminServiceImpl implements ApplicationManagem
                         applicationWrapper.getDeviceIdentifiers().size() > 0) {
                     activity = appManagerConnector.installApplicationForDevices(operation, applicationWrapper.getDeviceIdentifiers());
                 } else {
-                    throw new InputValidationException(new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage(
-                            "No application installation criteria i.e. user/role/device is given").build());
+                    return Response.status(Response.Status.BAD_REQUEST).entity(
+                            new ErrorResponse.ErrorResponseBuilder().setMessage(
+                                    "No application installation criteria i.e. user/role/device is given").build()).build();
                 }
             }
             return Response.status(Response.Status.ACCEPTED).entity(activity).build();
         } catch (ApplicationManagementException e) {
-            String msg = "ErrorResponse occurred while processing application installation request";
+            String msg = "Error occurred while processing application installation request";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         } catch (UnknownApplicationTypeException e) {
             String msg = "The type of application requested to be installed is not supported";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         }
     }
 
@@ -130,22 +129,22 @@ public class ApplicationManagementAdminServiceImpl implements ApplicationManagem
                         applicationWrapper.getDeviceIdentifiers().size() > 0) {
                     activity = appManagerConnector.installApplicationForDevices(operation, applicationWrapper.getDeviceIdentifiers());
                 } else {
-                    throw new InputValidationException(
-                            new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage(
-                            "No application un-installation criteria i.e. user/role/device is given").build());
+                    return Response.status(Response.Status.BAD_REQUEST).entity(
+                            new ErrorResponse.ErrorResponseBuilder().setMessage(
+                                    "No application un-installation criteria i.e. user/role/device is given").build()).build();
                 }
             }
             return Response.status(Response.Status.ACCEPTED).entity(activity).build();
         } catch (ApplicationManagementException e) {
-            String msg = "ErrorResponse occurred while processing application un-installation request";
+            String msg = "Error occurred while processing application un-installation request";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         } catch (UnknownApplicationTypeException e) {
             String msg = "The type of application requested to be un-installed is not supported";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         }
     }
 

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/admin/DeviceManagementAdminServiceImpl.java

@@ -28,8 +28,6 @@ import org.wso2.carbon.device.mgt.common.DeviceManagementException;
 import org.wso2.carbon.device.mgt.jaxrs.beans.DeviceList;
 import org.wso2.carbon.device.mgt.jaxrs.beans.ErrorResponse;
 import org.wso2.carbon.device.mgt.jaxrs.service.api.admin.DeviceManagementAdminService;
-import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.*;
-import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.NotFoundException;
 import org.wso2.carbon.device.mgt.jaxrs.util.DeviceMgtAPIUtils;
 
 import javax.ws.rs.*;
@@ -55,21 +53,16 @@ public class DeviceManagementAdminServiceImpl implements DeviceManagementAdminSe
         try {
             int currentTenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             if (MultitenantConstants.SUPER_TENANT_ID != currentTenantId) {
-                throw new UnauthorizedAccessException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(401l).setMessage(
-                        "Current logged in user is not authorized to perform this operation").build());
+                return Response.status(Response.Status.UNAUTHORIZED).entity(
+                        new ErrorResponse.ErrorResponseBuilder().setMessage(
+                                "Current logged in user is not authorized to perform this operation").build()).build();
             }
             PrivilegedCarbonContext.startTenantFlow();
             PrivilegedCarbonContext.getThreadLocalCarbonContext().setTenantDomain(tenantDomain);
             PrivilegedCarbonContext.getThreadLocalCarbonContext().setTenantId(DeviceMgtAPIUtils.getTenantId(tenantDomain));
 
             List<Device> devices = DeviceMgtAPIUtils.getDeviceManagementService().
-                getDevicesByNameAndType(name, type, offset, limit);
-            if (devices == null || devices.size() == 0) {
-                throw new NotFoundException(
-                        new ErrorResponse.ErrorResponseBuilder().setCode(404l).setMessage("No device, which carries" +
-                                " the name '" + name + "', is currently enrolled in the system").build());
-            }
+                    getDevicesByNameAndType(name, type, offset, limit);
 
             // setting up paginated result
             DeviceList deviceList = new DeviceList();
@@ -80,8 +73,8 @@ public class DeviceManagementAdminServiceImpl implements DeviceManagementAdminSe
         } catch (DeviceManagementException e) {
             String msg = "Error occurred at server side while fetching device list.";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         } finally {
             PrivilegedCarbonContext.endTenantFlow();
         }

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/util/CredentialManagementResponseBuilder.java

@@ -21,11 +21,9 @@ package org.wso2.carbon.device.mgt.jaxrs.util;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.wso2.carbon.device.mgt.jaxrs.beans.ErrorResponse;
-import org.wso2.carbon.device.mgt.jaxrs.beans.PasswordResetWrapper;
 import org.wso2.carbon.device.mgt.jaxrs.beans.OldPasswordResetWrapper;
-import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.InputValidationException;
+import org.wso2.carbon.device.mgt.jaxrs.beans.PasswordResetWrapper;
 import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.RequestValidationUtil;
-import org.wso2.carbon.device.mgt.jaxrs.service.impl.util.UnexpectedServerErrorException;
 import org.wso2.carbon.user.api.UserStoreException;
 import org.wso2.carbon.user.api.UserStoreManager;
 
@@ -44,7 +42,8 @@ public class CredentialManagementResponseBuilder {
 
     /**
      * Builds the response to change the password of a user
-     * @param username - Username of the user.
+     *
+     * @param username    - Username of the user.
      * @param credentials - User credentials
      * @return Response Object
      */
@@ -52,38 +51,39 @@ public class CredentialManagementResponseBuilder {
         try {
             UserStoreManager userStoreManager = DeviceMgtAPIUtils.getUserStoreManager();
             if (!userStoreManager.isExistingUser(username)) {
-                throw new InputValidationException(
-                        new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage("No user found with the username "
-                                + username).build());
+                return Response.status(Response.Status.NOT_FOUND).entity(
+                        new ErrorResponse.ErrorResponseBuilder().setMessage("No user found with the username '"
+                                + username + "'").build()).build();
             }
             RequestValidationUtil.validateCredentials(credentials);
 
             if (!validateCredential(credentials.getNewPassword())) {
                 String errorMsg = DeviceMgtAPIUtils.getRealmService().getBootstrapRealmConfiguration()
                         .getUserStoreProperty(PASSWORD_VALIDATION_ERROR_MSG_TAG);
-                throw new InputValidationException(
-                        new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage(errorMsg).build());
+                return Response.status(Response.Status.BAD_REQUEST).entity(
+                        new ErrorResponse.ErrorResponseBuilder().setMessage(errorMsg).build()).build();
             }
             userStoreManager.updateCredential(username, credentials.getNewPassword(),
-                                              credentials.getOldPassword());
+                    credentials.getOldPassword());
             return Response.status(Response.Status.OK).entity("UserImpl password by username: " +
                     username + " was successfully changed.").build();
         } catch (UserStoreException e) {
             log.error(e.getMessage(), e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(e.getMessage()).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(e.getMessage()).build()).build();
         } catch (UnsupportedEncodingException e) {
             String msg = "Could not change the password of the user: " + username +
                     ". The Character Encoding is not supported.";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         }
     }
 
     /**
      * Builds the response to reset the password of a user
-     * @param username - Username of the user.
+     *
+     * @param username    - Username of the user.
      * @param credentials - User credentials
      * @return Response Object
      */
@@ -91,35 +91,35 @@ public class CredentialManagementResponseBuilder {
         try {
             UserStoreManager userStoreManager = DeviceMgtAPIUtils.getUserStoreManager();
             if (!userStoreManager.isExistingUser(username)) {
-                throw new InputValidationException(
-                        new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage("No user found with the username "
-                                + username).build());
+                return Response.status(Response.Status.BAD_REQUEST).entity(
+                        new ErrorResponse.ErrorResponseBuilder().setMessage("No user found with the username "
+                                + username).build()).build();
             }
             if (credentials == null || credentials.getNewPassword() == null) {
-                throw new InputValidationException(
-                        new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage("Password cannot be empty."
-                                + username).build());
+                return Response.status(Response.Status.BAD_REQUEST).entity(
+                        new ErrorResponse.ErrorResponseBuilder().setMessage("Password cannot be empty."
+                                + username).build()).build();
             }
             if (!validateCredential(credentials.getNewPassword())) {
                 String errorMsg = DeviceMgtAPIUtils.getRealmService().getBootstrapRealmConfiguration()
                         .getUserStoreProperty(PASSWORD_VALIDATION_ERROR_MSG_TAG);
-                throw new InputValidationException(
-                        new ErrorResponse.ErrorResponseBuilder().setCode(400l).setMessage(errorMsg).build());
+                return Response.status(Response.Status.BAD_REQUEST).entity(
+                        new ErrorResponse.ErrorResponseBuilder().setMessage(errorMsg).build()).build();
             }
             userStoreManager.updateCredentialByAdmin(username, credentials.getNewPassword());
             return Response.status(Response.Status.OK).entity("UserImpl password by username: " +
                     username + " was successfully changed.").build();
         } catch (UserStoreException e) {
-            String msg = "ErrorResponse occurred while updating the credentials of user '" + username + "'";
+            String msg = "Error occurred while updating the credentials of user '" + username + "'";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         } catch (UnsupportedEncodingException e) {
             String msg = "Could not change the password of the user: " + username +
                     ". The Character Encoding is not supported.";
             log.error(msg, e);
-            throw new UnexpectedServerErrorException(
-                    new ErrorResponse.ErrorResponseBuilder().setCode(500l).setMessage(msg).build());
+            return Response.serverError().entity(
+                    new ErrorResponse.ErrorResponseBuilder().setMessage(msg).build()).build();
         }
     }