Device Type not present in DB, return null instead of dummy object

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/DeviceTypeDAOImpl.java

@@ -120,6 +120,7 @@ public class DeviceTypeDAOImpl implements DeviceTypeDAO {
         Connection conn = null;
         PreparedStatement stmt = null;
         ResultSet rs = null;
+        DeviceType deviceType = null;
         try {
             conn = this.getConnection();
             String sql = "SELECT ID From DM_DEVICE_TYPE WHERE NAME = ?";
@@ -127,14 +128,11 @@ public class DeviceTypeDAOImpl implements DeviceTypeDAO {
             stmt.setString(1, type);
             rs = stmt.executeQuery();
 
-            int id = -1;
             if (rs.next()) {
-                id = rs.getInt("ID");
-            }
-            DeviceType deviceType = new DeviceType();
-            deviceType.setId(id);
+                deviceType = new DeviceType();
+                deviceType.setId(rs.getInt("ID"));
                 deviceType.setName(type);
-
+            }
             return deviceType;
         } catch (SQLException e) {
             throw new DeviceManagementDAOException("Error occurred while fetch device type id for device type " +

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/internal/DeviceManagementServiceComponent.java

@@ -55,10 +55,9 @@ import org.wso2.carbon.device.mgt.core.operation.mgt.dao.OperationManagementDAOF
 import org.wso2.carbon.device.mgt.core.service.DeviceManagementService;
 import org.wso2.carbon.device.mgt.core.service.DeviceManagementServiceImpl;
 import org.wso2.carbon.device.mgt.core.util.DeviceManagementSchemaInitializer;
+import org.wso2.carbon.user.core.service.RealmService;
 import org.wso2.carbon.ndatasource.core.DataSourceService;
 import org.wso2.carbon.registry.core.service.RegistryService;
-import org.wso2.carbon.user.core.service.RealmService;
-
 import java.util.ArrayList;
 import java.util.List;
 

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/util/DeviceManagerUtil.java

@@ -111,23 +111,23 @@ public final class DeviceManagerUtil {
     /**
      * Adds a new device type to the database if it does not exists.
      *
-     * @param deviceType device type
+     * @param typeName device type
      * @return status of the operation
      */
-    public static boolean registerDeviceType(String deviceType) throws DeviceManagementException {
+    public static boolean registerDeviceType(String typeName) throws DeviceManagementException {
         boolean status;
         try {
             DeviceTypeDAO deviceTypeDAO = DeviceManagementDAOFactory.getDeviceTypeDAO();
-            DeviceType deviceTypeId = deviceTypeDAO.getDeviceType(deviceType);
-            if (deviceTypeId == null) {
+            DeviceType deviceType = deviceTypeDAO.getDeviceType(typeName);
+            if (deviceType == null) {
                 DeviceType dt = new DeviceType();
-                dt.setName(deviceType);
+                dt.setName(typeName);
                 deviceTypeDAO.addDeviceType(dt);
             }
             status = true;
         } catch (DeviceManagementDAOException e) {
             throw new DeviceManagementException("Error occurred while registering the device type '" +
-                    deviceType + "'", e);
+                    typeName + "'", e);
         }
         return status;
     }
@@ -135,22 +135,22 @@ public final class DeviceManagerUtil {
     /**
      * Un-registers an existing device type from the device management metadata repository.
      *
-     * @param deviceType device type
+     * @param typeName device type
      * @return status of the operation
      */
-    public static boolean unregisterDeviceType(String deviceType) throws DeviceManagementException {
+    public static boolean unregisterDeviceType(String typeName) throws DeviceManagementException {
         try {
             DeviceTypeDAO deviceTypeDAO = DeviceManagementDAOFactory.getDeviceTypeDAO();
-            DeviceType deviceTypeId = deviceTypeDAO.getDeviceType(deviceType);
-            if (deviceTypeId == null) {
+            DeviceType deviceType = deviceTypeDAO.getDeviceType(typeName);
+            if (deviceType == null) {
                 DeviceType dt = new DeviceType();
-                dt.setName(deviceType);
-                deviceTypeDAO.removeDeviceType(deviceType);
+                dt.setName(typeName);
+                deviceTypeDAO.removeDeviceType(typeName);
             }
             return true;
         } catch (DeviceManagementDAOException e) {
             throw new DeviceManagementException("Error occurred while registering the device type '" +
-                    deviceType + "'", e);
+                    typeName + "'", e);
         }
     }