Merge branch 'master' of https://github.com/wso2/carbon-device-mgt

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

@@ -32,6 +32,52 @@ import java.sql.SQLException;
 import java.util.Hashtable;
 import java.util.List;
 
+/**
+ * This class intends to act as the primary entity that hides all DAO instantiation related complexities and logic so
+ * that the business objection handling layer doesn't need to be aware of the same providing seamless plug-ability of
+ * different data sources, connection acquisition mechanisms as well as different forms of DAO implementations to the
+ * high-level implementations that require device management related metadata persistence.
+ * <p/>
+ * In addition, this also provides means to handle transactions across multiple device management related DAO objects.
+ * Any high-level business logic that requires transaction handling to be done via utility methods provided in
+ * DeviceManagementDAOFactory should adhere the following guidelines to avoid any unexpected behaviour that can cause
+ * as a result of improper use of the aforementioned utility method.
+ * <p/>
+ * Any transaction that commits data into the underlying data persistence mechanism MUST follow the sequence of
+ * operations mentioned below.
+ * <p/>
+ * <pre>
+ * {@code
+ * try {
+ *      DeviceManagementDAOFactory.beginTransaction();
+ *      .....
+ *      DeviceManagementDAOFactory.commitTransaction();
+ *      return success;
+ * } catch (Exception e) {
+ *      DeviceManagementDAOFactory.rollbackTransaction();
+ *      throw new DeviceManagementException("Error occurred while ...", e);
+ * } finally {
+ *      DeviceManagementDAOFactory.closeConnection();
+ * }
+ * }
+ * </pre>
+ * <p/>
+ * Any transaction that retrieves data from the underlying data persistence mechanism MUST follow the sequence of
+ * operations mentioned below.
+ * <p/>
+ * <pre>
+ * {@code
+ * try {
+ *      DeviceManagementDAOFactory.openConnection();
+ *      .....
+ * } catch (Exception e) {
+ *      throw new DeviceManagementException("Error occurred while ..., e);
+ * } finally {
+ *      DeviceManagementDAOFactory.closeConnection();
+ * }
+ * }
+ * </pre>
+ */
 public class DeviceManagementDAOFactory {
 
     private static DataSource dataSource;
@@ -87,7 +133,7 @@ public class DeviceManagementDAOFactory {
         return currentConnection.get();
     }
 
-    public static void commitTransaction() throws TransactionManagementException {
+    public static void commitTransaction() {
         try {
             Connection conn = currentConnection.get();
             if (conn != null) {
@@ -99,7 +145,7 @@ public class DeviceManagementDAOFactory {
                 }
             }
         } catch (SQLException e) {
-            throw new TransactionManagementException("Error occurred while committing the transaction", e);
+            log.error("Error occurred while committing the transaction", e);
         }
     }
 

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

@@ -81,7 +81,7 @@ public class ApplicationDAOImpl implements ApplicationDAO {
         Connection conn;
         PreparedStatement stmt = null;
         ResultSet rs;
-        List<Integer> applicationIds = new ArrayList<Integer>();
+        List<Integer> applicationIds = new ArrayList<>();
         try {
             conn = this.getConnection();
             stmt = conn.prepareStatement("INSERT INTO DM_APPLICATION (NAME, PLATFORM, CATEGORY, " +
@@ -118,13 +118,10 @@ public class ApplicationDAOImpl implements ApplicationDAO {
 
     @Override
     public List<Integer> removeApplications(List<Application> apps, int tenantId) throws DeviceManagementDAOException {
-
         Connection conn = null;
         PreparedStatement stmt = null;
         ResultSet rs = null;
-        int applicationId = -1;
+        List<Integer> applicationIds = new ArrayList<>();
-        List<Integer> applicationIds = new ArrayList<Integer>();
-
         try {
             conn = this.getConnection();
             conn.setAutoCommit(false);
@@ -144,7 +141,9 @@ public class ApplicationDAOImpl implements ApplicationDAO {
             return applicationIds;
         } catch (SQLException e) {
             try {
+                if (conn != null) {
                     conn.rollback();
+                }
             } catch (SQLException e1) {
                 log.warn("Error occurred while roll-backing the transaction", e);
             }
@@ -189,11 +188,8 @@ public class ApplicationDAOImpl implements ApplicationDAO {
     public List<Application> getInstalledApplications(int deviceId) throws DeviceManagementDAOException {
         Connection conn;
         PreparedStatement stmt = null;
-        List<Application> applications = new ArrayList<Application>();
+        List<Application> applications = new ArrayList<>();
         Application application;
-        ByteArrayInputStream bais;
-        ObjectInputStream ois;
-
         try {
             conn = this.getConnection();
             stmt = conn.prepareStatement("Select ID, NAME, APP_IDENTIFIER, PLATFORM, CATEGORY, VERSION, TYPE, " +
@@ -220,7 +216,6 @@ public class ApplicationDAOImpl implements ApplicationDAO {
     }
 
     private Application loadApplication(ResultSet rs) throws DeviceManagementDAOException {
-
         ByteArrayInputStream bais;
         ObjectInputStream ois;
         Properties properties;
@@ -246,18 +241,12 @@ public class ApplicationDAOImpl implements ApplicationDAO {
             application.setVersion(rs.getString("VERSION"));
             application.setApplicationIdentifier(rs.getString("APP_IDENTIFIER"));
 
-        }catch (IOException ex){
+        } catch (IOException e) {
-            String errorMsg = "IO error occurred fetch at app properties";
+            throw new DeviceManagementDAOException("IO error occurred fetch at app properties", e);
-            log.error(errorMsg, ex);
+        } catch (ClassNotFoundException e) {
-            throw new DeviceManagementDAOException(errorMsg, ex);
+            throw new DeviceManagementDAOException("Class not found error occurred fetch at app properties", e);
-        }catch (ClassNotFoundException cex){
+        } catch (SQLException e) {
-            String errorMsg = "Class not found error occurred fetch at app properties";
+            throw new DeviceManagementDAOException("SQL error occurred fetch at application", e);
-            log.error(errorMsg, cex);
-            throw new DeviceManagementDAOException(errorMsg, cex);
-        }catch (SQLException ex){
-            String errorMsg = "SQL error occurred fetch at application";
-            log.error(errorMsg, ex);
-            throw new DeviceManagementDAOException(errorMsg, ex);
         }
 
         return application;

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

@@ -38,7 +38,6 @@ import java.util.Properties;
 
 public class ApplicationMappingDAOImpl implements ApplicationMappingDAO {
 
-    private static final Log log = LogFactory.getLog(ApplicationMappingDAOImpl.class);
     @Override
     public int addApplicationMapping(int deviceId, int applicationId,
                                      int tenantId) throws DeviceManagementDAOException {
@@ -74,7 +73,7 @@ public class ApplicationMappingDAOImpl implements ApplicationMappingDAO {
         Connection conn;
         PreparedStatement stmt = null;
         ResultSet rs = null;
-        List<Integer> mappingIds = new ArrayList<Integer>();
+        List<Integer> mappingIds = new ArrayList<>();
         try {
             conn = this.getConnection();
             String sql = "INSERT INTO DM_DEVICE_APPLICATION_MAPPING (DEVICE_ID, APPLICATION_ID, " +
@@ -102,12 +101,9 @@ public class ApplicationMappingDAOImpl implements ApplicationMappingDAO {
     }
 
     @Override
-    public void removeApplicationMapping(int deviceId, List<Integer> appIdList, int tenantId)
+    public void removeApplicationMapping(int deviceId, List<Integer> appIdList,
-            throws DeviceManagementDAOException {
+                                         int tenantId) throws DeviceManagementDAOException {
-
         Connection conn;
-        ResultSet rs;
-        int mappingId = -1;
         PreparedStatement stmt = null;
         try {
             conn = this.getConnection();

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

@@ -18,8 +18,6 @@
 
 package org.wso2.carbon.device.mgt.core.dao.impl;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
 import org.wso2.carbon.device.mgt.common.Device;
 import org.wso2.carbon.device.mgt.common.DeviceIdentifier;
 import org.wso2.carbon.device.mgt.common.EnrolmentInfo;
@@ -36,8 +34,6 @@ import java.util.List;
 
 public class DeviceDAOImpl implements DeviceDAO {
 
-    private static final Log log = LogFactory.getLog(DeviceDAOImpl.class);
-
     @Override
     public int addDevice(int typeId, Device device, int tenantId) throws DeviceManagementDAOException {
         Connection conn;
@@ -63,8 +59,8 @@ public class DeviceDAOImpl implements DeviceDAO {
             }
             return deviceId;
         } catch (SQLException e) {
-            throw new DeviceManagementDAOException("Error occurred while enrolling device " +
+            throw new DeviceManagementDAOException("Error occurred while enrolling device '" + device.getName() +
-                                                   "'" + device.getName() + "'", e);
+                    "'", e);
         } finally {
             DeviceManagementDAOUtil.cleanupResources(stmt, rs);
         }
@@ -158,7 +154,7 @@ public class DeviceDAOImpl implements DeviceDAO {
             stmt.setInt(1, tenantId);
             stmt.setInt(2, tenantId);
             rs = stmt.executeQuery();
-            devices = new ArrayList<Device>();
+            devices = new ArrayList<>();
             while (rs.next()) {
                 Device device = this.loadDevice(rs);
                 devices.add(device);
@@ -191,7 +187,7 @@ public class DeviceDAOImpl implements DeviceDAO {
             stmt.setInt(2, tenantId);
             stmt.setInt(3, tenantId);
             rs = stmt.executeQuery();
-            devices = new ArrayList<Device>();
+            devices = new ArrayList<>();
             while (rs.next()) {
                 Device device = this.loadDevice(rs);
                 devices.add(device);
@@ -208,7 +204,7 @@ public class DeviceDAOImpl implements DeviceDAO {
     public List<Device> getDevicesOfUser(String username, int tenantId) throws DeviceManagementDAOException {
         Connection conn;
         PreparedStatement stmt = null;
-        List<Device> devices = new ArrayList<Device>();
+        List<Device> devices = new ArrayList<>();
         try {
             conn = this.getConnection();
             String sql =
@@ -282,7 +278,7 @@ public class DeviceDAOImpl implements DeviceDAO {
     public List<Device> getDevicesByName(String deviceName, int tenantId) throws DeviceManagementDAOException {
         Connection conn;
         PreparedStatement stmt = null;
-        List<Device> devices = new ArrayList<Device>();
+        List<Device> devices = new ArrayList<>();
         try {
             conn = this.getConnection();
             String sql =
@@ -491,7 +487,7 @@ public class DeviceDAOImpl implements DeviceDAO {
             throws DeviceManagementDAOException {
         Connection conn;
         PreparedStatement stmt = null;
-        List<Device> devices = new ArrayList<Device>();
+        List<Device> devices = new ArrayList<>();
         try {
             conn = this.getConnection();
             String sql =

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

@@ -17,16 +17,12 @@
  */
 package org.wso2.carbon.device.mgt.core.dao.impl;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.wso2.carbon.device.mgt.common.TransactionManagementException;
 import org.wso2.carbon.device.mgt.core.dao.DeviceManagementDAOException;
 import org.wso2.carbon.device.mgt.core.dao.DeviceManagementDAOFactory;
 import org.wso2.carbon.device.mgt.core.dao.DeviceTypeDAO;
 import org.wso2.carbon.device.mgt.core.dao.util.DeviceManagementDAOUtil;
 import org.wso2.carbon.device.mgt.core.dto.DeviceType;
 
-import javax.sql.DataSource;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/operation/mgt/OperationManagerImpl.java

@@ -23,6 +23,7 @@ import org.apache.commons.logging.LogFactory;
 import org.wso2.carbon.context.CarbonContext;
 import org.wso2.carbon.device.mgt.common.DeviceIdentifier;
 import org.wso2.carbon.device.mgt.common.EnrolmentInfo;
+import org.wso2.carbon.device.mgt.common.TransactionManagementException;
 import org.wso2.carbon.device.mgt.common.operation.mgt.Operation;
 import org.wso2.carbon.device.mgt.common.operation.mgt.OperationManagementException;
 import org.wso2.carbon.device.mgt.common.operation.mgt.OperationManager;
@@ -36,6 +37,7 @@ import org.wso2.carbon.device.mgt.core.operation.mgt.dao.OperationMappingDAO;
 import org.wso2.carbon.device.mgt.core.operation.mgt.dao.util.OperationDAOUtil;
 import org.wso2.carbon.device.mgt.core.operation.mgt.util.OperationCreateTimeComparator;
 
+import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -70,7 +72,6 @@ public class OperationManagerImpl implements OperationManager {
     @Override
     public int addOperation(Operation operation,
                             List<DeviceIdentifier> deviceIds) throws OperationManagementException {
-
         if (log.isDebugEnabled()) {
             log.debug("operation:[" + operation.toString() + "]");
             for (DeviceIdentifier deviceIdentifier : deviceIds) {
@@ -101,19 +102,15 @@ public class OperationManagerImpl implements OperationManager {
             OperationManagementDAOFactory.commitTransaction();
             return operationId;
         } catch (OperationManagementDAOException e) {
-            try {
             OperationManagementDAOFactory.rollbackTransaction();
-            } catch (OperationManagementDAOException e1) {
-                log.warn("Error occurred while roll-backing the transaction", e1);
-            }
             throw new OperationManagementException("Error occurred while adding operation", e);
         } catch (DeviceManagementDAOException e) {
-            try {
             OperationManagementDAOFactory.rollbackTransaction();
-            } catch (OperationManagementDAOException e1) {
-                log.warn("Error occurred while roll-backing the transaction", e1);
-            }
             throw new OperationManagementException("Error occurred while retrieving device metadata", e);
+        } catch (TransactionManagementException e) {
+            throw new OperationManagementException("Error occurred while initiating the transaction", e);
+        } finally {
+            OperationManagementDAOFactory.closeConnection();
         }
     }
 
@@ -122,7 +119,7 @@ public class OperationManagerImpl implements OperationManager {
         int enrolmentId;
         List<Operation> operations = new ArrayList<>();
         try {
-            OperationManagementDAOFactory.getConnection();
+            OperationManagementDAOFactory.openConnection();
 
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
@@ -145,12 +142,10 @@ public class OperationManagerImpl implements OperationManager {
         } catch (DeviceManagementDAOException e) {
             throw new OperationManagementException("Error occurred while retrieving metadata of '" +
                     deviceId.getType() + "' device carrying the identifier '" + deviceId.getId() + "'");
+        } catch (SQLException e) {
+            throw new OperationManagementException("Error occurred while opening a connection to the data source", e);
         } finally {
-            try {
             OperationManagementDAOFactory.closeConnection();
-            } catch (OperationManagementDAOException e) {
-                log.warn("Error occurred while closing data source connection", e);
-            }
         }
 
     }
@@ -165,7 +160,7 @@ public class OperationManagerImpl implements OperationManager {
         List<Operation> operations = new ArrayList<>();
         List<org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation> dtoOperationList = new ArrayList<>();
         try {
-            OperationManagementDAOFactory.getConnection();
+            OperationManagementDAOFactory.openConnection();
 
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
@@ -202,12 +197,10 @@ public class OperationManagerImpl implements OperationManager {
             throw new OperationManagementException("Error occurred while retrieving the device " +
                     "for device Identifier type -'" + deviceId.getType() + "' and device Id '"
                     + deviceId.getId() + "'", e);
+        } catch (SQLException e) {
+            throw new OperationManagementException("Error occurred while opening a connection to the data source", e);
         } finally {
-            try {
             OperationManagementDAOFactory.closeConnection();
-            } catch (OperationManagementDAOException e) {
-                log.warn("Error occurred while closing data source connection", e);
-            }
         }
     }
 
@@ -220,7 +213,7 @@ public class OperationManagerImpl implements OperationManager {
         Operation operation = null;
         int enrolmentId;
         try {
-            OperationManagementDAOFactory.getConnection();
+            OperationManagementDAOFactory.openConnection();
 
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
@@ -258,23 +251,19 @@ public class OperationManagerImpl implements OperationManager {
         } catch (DeviceManagementDAOException e) {
             throw new OperationManagementException("Error occurred while retrieving the device " +
                     "for device Identifier type -'" + deviceId.getType() + "' and device Id '" + deviceId.getId(), e);
+        } catch (SQLException e) {
+            throw new OperationManagementException("Error occurred while opening a connection to the data source", e);
         } finally {
-            try {
             OperationManagementDAOFactory.closeConnection();
-            } catch (OperationManagementDAOException e) {
-                log.warn("Error occurred while closing data source connection", e);
-            }
         }
     }
 
     @Override
     public void updateOperation(DeviceIdentifier deviceId, Operation operation) throws OperationManagementException {
         int operationId = operation.getId();
-
         if (log.isDebugEnabled()) {
             log.debug("operation Id:" + operationId + " status:" + operation.getStatus());
         }
-
         try {
             OperationManagementDAOFactory.beginTransaction();
 
@@ -282,65 +271,49 @@ public class OperationManagerImpl implements OperationManager {
             int enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
 
             if (operation.getStatus() != null) {
-                OperationManagementDAOFactory.beginTransaction();
                 operationDAO.updateOperationStatus(enrolmentId, operationId,
                         org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation.Status
                                 .valueOf(operation.getStatus().toString()));
             }
-
-
             if (operation.getOperationResponse() != null) {
-                OperationManagementDAOFactory.beginTransaction();
                 operationDAO.addOperationResponse(enrolmentId, operationId, operation.getOperationResponse());
-                OperationManagementDAOFactory.commitTransaction();
             }
+            OperationManagementDAOFactory.commitTransaction();
         } catch (OperationManagementDAOException e) {
-            try {
             OperationManagementDAOFactory.rollbackTransaction();
-            } catch (OperationManagementDAOException e1) {
-                log.warn("Error occurred while roll-backing the update operation transaction", e1);
-            }
             throw new OperationManagementException("Error occurred while updating the operation: " + operationId +
                     " status:" + operation.getStatus(), e);
         } catch (DeviceManagementDAOException e) {
-            try {
             OperationManagementDAOFactory.rollbackTransaction();
-            } catch (OperationManagementDAOException e1) {
-                log.warn("Error occurred while roll-backing the update operation transaction", e1);
-            }
             throw new OperationManagementException("Error occurred while fetching the device for device identifier: " +
                     deviceId.getId() + "type:" + deviceId.getType(), e);
+        } catch (TransactionManagementException e) {
+            throw new OperationManagementException("Error occurred while initiating a transaction", e);
         } finally {
-            try {
             OperationManagementDAOFactory.closeConnection();
-            } catch (OperationManagementDAOException e) {
-                log.warn("Error occurred while closing data source connection", e);
-            }
         }
     }
 
     @Override
     public void deleteOperation(int operationId) throws OperationManagementException {
-
         try {
             OperationManagementDAOFactory.beginTransaction();
-            org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation operation = operationDAO.getOperation
-                    (operationId);
 
+            org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation operation =
+                    operationDAO.getOperation(operationId);
             if (operation == null) {
                 throw new OperationManagementException("Operation not found for operation id:" + operationId);
             }
-
             lookupOperationDAO(operation).deleteOperation(operationId);
-            OperationManagementDAOFactory.commitTransaction();
 
+            OperationManagementDAOFactory.commitTransaction();
         } catch (OperationManagementDAOException e) {
-            try {
             OperationManagementDAOFactory.rollbackTransaction();
-            } catch (OperationManagementDAOException e1) {
-                log.warn("Error occurred while roll-backing the delete operation transaction", e1);
-            }
             throw new OperationManagementException("Error occurred while deleting the operation: " + operationId, e);
+        } catch (TransactionManagementException e) {
+            throw new OperationManagementException("Error occurred while initiating a transaction", e);
+        } finally {
+            OperationManagementDAOFactory.closeConnection();
         }
     }
 
@@ -349,13 +322,12 @@ public class OperationManagerImpl implements OperationManager {
             throws OperationManagementException {
         int enrolmentId;
         Operation operation;
-
         if (log.isDebugEnabled()) {
             log.debug("Operation Id:" + operationId + " Device Type:" + deviceId.getType() + " Device Identifier:" +
                     deviceId.getId());
         }
         try {
-            OperationManagementDAOFactory.getConnection();
+            OperationManagementDAOFactory.openConnection();
 
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
@@ -376,12 +348,11 @@ public class OperationManagerImpl implements OperationManager {
             } else if (dtoOperation.getType()
                     .equals(org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation.Type.CONFIG)) {
                 dtoOperation = configOperationDAO.getOperation(dtoOperation.getId());
-            } else if (dtoOperation.getType().equals(org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation.Type
+            } else if (dtoOperation.getType().equals(
-                    .PROFILE)) {
+                    org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation.Type.PROFILE)) {
                 dtoOperation = profileOperationDAO.getOperation(dtoOperation.getId());
-            } else if (dtoOperation.getType().equals(org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation.Type
+            } else if (dtoOperation.getType().equals(
-                    .POLICY)) {
+                    org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation.Type.POLICY)) {
-
                 dtoOperation = policyOperationDAO.getOperation(dtoOperation.getId());
             }
 
@@ -398,12 +369,10 @@ public class OperationManagerImpl implements OperationManager {
             throw new OperationManagementException("Error occurred while retrieving the device " +
                     "for device Identifier type -'" + deviceId.getType() + "' and device Id '" +
                     deviceId.getId() + "'", e);
+        } catch (SQLException e) {
+            throw new OperationManagementException("Error occurred while opening connection to the data source", e);
         } finally {
-            try {
             OperationManagementDAOFactory.closeConnection();
-            } catch (OperationManagementDAOException e) {
-                log.warn("Error occurred while closing data source connection", e);
-            }
         }
         return operation;
     }
@@ -415,7 +384,7 @@ public class OperationManagerImpl implements OperationManager {
         List<org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation> dtoOperationList =
                 new ArrayList<>();
         try {
-            OperationManagementDAOFactory.getConnection();
+            OperationManagementDAOFactory.openConnection();
 
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             int enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
@@ -455,18 +424,15 @@ public class OperationManagerImpl implements OperationManager {
         } catch (DeviceManagementDAOException e) {
             throw new OperationManagementException("Error occurred while retrieving the device " +
                     "for device Identifier type -'" + deviceId.getType() + "' and device Id '" + deviceId.getId(), e);
+        } catch (SQLException e) {
+            throw new OperationManagementException("Error occurred while opening a connection to the data source", e);
         } finally {
-            try {
             OperationManagementDAOFactory.closeConnection();
-            } catch (OperationManagementDAOException e) {
-                log.warn("Error occurred while closing data source connection", e);
-            }
         }
     }
 
     @Override
     public Operation getOperation(int operationId) throws OperationManagementException {
-
         Operation operation;
         try {
             OperationManagementDAOFactory.getConnection();
@@ -480,8 +446,9 @@ public class OperationManagerImpl implements OperationManager {
             if (dtoOperation.getType()
                     .equals(org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation.Type.COMMAND)) {
                 org.wso2.carbon.device.mgt.core.dto.operation.mgt.CommandOperation commandOperation;
-                commandOperation = (org.wso2.carbon.device.mgt.core.dto.operation.mgt.CommandOperation) commandOperationDAO
+                commandOperation =
-                        .getOperation(dtoOperation.getId());
+                        (org.wso2.carbon.device.mgt.core.dto.operation.mgt.CommandOperation) commandOperationDAO.
+                                getOperation(dtoOperation.getId());
                 dtoOperation.setEnabled(commandOperation.isEnabled());
             } else if (dtoOperation.getType()
                     .equals(org.wso2.carbon.device.mgt.core.dto.operation.mgt.Operation.Type.CONFIG)) {
@@ -496,15 +463,12 @@ public class OperationManagerImpl implements OperationManager {
             }
             operation = OperationDAOUtil.convertOperation(dtoOperation);
         } catch (OperationManagementDAOException e) {
-            String errorMsg = "Error occurred while retrieving the operation with operation Id '" + operationId;
+            throw new OperationManagementException("Error occurred while retrieving the operation with operation Id '" +
-            log.error(errorMsg, e);
+                    operationId, e);
-            throw new OperationManagementException(errorMsg, e);
+        } catch (SQLException e) {
+            throw new OperationManagementException("Error occurred while opening a connection to the data source", e);
         } finally {
-            try {
             OperationManagementDAOFactory.closeConnection();
-            } catch (OperationManagementDAOException e) {
-                log.warn("Error occurred while closing data source connection", e);
-            }
         }
         return operation;
     }

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/operation/mgt/dao/OperationManagementDAOFactory.java

@@ -20,6 +20,7 @@ package org.wso2.carbon.device.mgt.core.operation.mgt.dao;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.wso2.carbon.device.mgt.common.TransactionManagementException;
 import org.wso2.carbon.device.mgt.core.config.datasource.DataSourceConfig;
 import org.wso2.carbon.device.mgt.core.config.datasource.JNDILookupDefinition;
 import org.wso2.carbon.device.mgt.core.dao.util.DeviceManagementDAOUtil;
@@ -69,27 +70,29 @@ public class OperationManagementDAOFactory {
         dataSource = resolveDataSource(config);
     }
 
-    public static void beginTransaction() throws OperationManagementDAOException {
+    public static void beginTransaction() throws TransactionManagementException {
         try {
-            currentConnection.set(dataSource.getConnection());
+            Connection conn = dataSource.getConnection();
+            conn.setAutoCommit(false);
+            currentConnection.set(conn);
         } catch (SQLException e) {
-            throw new OperationManagementDAOException(
+            throw new TransactionManagementException(
                     "Error occurred while retrieving config.datasource connection", e);
         }
     }
 
-    public static Connection getConnection() throws OperationManagementDAOException {
+    public static void openConnection() throws SQLException {
-        if (currentConnection.get() == null) {
-            try {
         currentConnection.set(dataSource.getConnection());
-            } catch (SQLException e) {
-                throw new OperationManagementDAOException("Error occurred while retrieving data source connection", e);
     }
+
+    public static Connection getConnection() throws SQLException {
+        if (currentConnection.get() == null) {
+            currentConnection.set(dataSource.getConnection());
         }
         return currentConnection.get();
     }
 
-    public static void closeConnection() throws OperationManagementDAOException {
+    public static void closeConnection() {
         Connection con = currentConnection.get();
         if (con != null) {
             try {
@@ -101,7 +104,7 @@ public class OperationManagementDAOFactory {
         }
     }
 
-    public static void commitTransaction() throws OperationManagementDAOException {
+    public static void commitTransaction() {
         try {
             Connection conn = currentConnection.get();
             if (conn != null) {
@@ -113,13 +116,11 @@ public class OperationManagementDAOFactory {
                 }
             }
         } catch (SQLException e) {
-            throw new OperationManagementDAOException("Error occurred while committing the transaction", e);
+            log.error("Error occurred while committing the transaction", e);
-        } finally {
-            closeConnection();
         }
     }
 
-    public static void rollbackTransaction() throws OperationManagementDAOException {
+    public static void rollbackTransaction() {
         try {
             Connection conn = currentConnection.get();
             if (conn != null) {
@@ -131,9 +132,7 @@ public class OperationManagementDAOFactory {
                 }
             }
         } catch (SQLException e) {
-            throw new OperationManagementDAOException("Error occurred while roll-backing the transaction", e);
+            log.error("Error occurred while roll-backing the transaction", e);
-        } finally {
-            closeConnection();
         }
     }
 

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

@@ -35,10 +35,11 @@ public class CommandOperationDAOImpl extends OperationDAOImpl {
 
     @Override
     public int addOperation(Operation operation) throws OperationManagementDAOException {
-        int operationId = super.addOperation(operation);
+        int operationId;
         CommandOperation commandOp = (CommandOperation) operation;
         PreparedStatement stmt = null;
         try {
+            operationId = super.addOperation(operation);
             Connection conn = OperationManagementDAOFactory.getConnection();
             stmt = conn.prepareStatement("INSERT INTO DM_COMMAND_OPERATION(OPERATION_ID, ENABLED) VALUES(?, ?)");
             stmt.setInt(1, operationId);
@@ -66,7 +67,6 @@ public class CommandOperationDAOImpl extends OperationDAOImpl {
             throw new OperationManagementDAOException("Error occurred while adding operation metadata", e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt);
-            OperationManagementDAOFactory.closeConnection();
         }
     }
 
@@ -75,7 +75,6 @@ public class CommandOperationDAOImpl extends OperationDAOImpl {
         PreparedStatement stmt = null;
         try {
             super.deleteOperation(id);
-
             Connection connection = OperationManagementDAOFactory.getConnection();
             stmt = connection.prepareStatement("DELETE DM_COMMAND_OPERATION WHERE OPERATION_ID = ?");
             stmt.setInt(1, id);
@@ -84,7 +83,6 @@ public class CommandOperationDAOImpl extends OperationDAOImpl {
             throw new OperationManagementDAOException("Error occurred while deleting operation metadata", e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt);
-            OperationManagementDAOFactory.closeConnection();
         }
     }
 
@@ -108,7 +106,6 @@ public class CommandOperationDAOImpl extends OperationDAOImpl {
                     "object available for the id '" + id, e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return commandOperation;
     }
@@ -148,7 +145,6 @@ public class CommandOperationDAOImpl extends OperationDAOImpl {
                     "for the device'" + enrolmentId + "' with status '" + status.toString(), e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return commandOperations;
     }

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

@@ -41,9 +41,10 @@ public class ConfigOperationDAOImpl extends OperationDAOImpl {
 
     @Override
     public int addOperation(Operation operation) throws OperationManagementDAOException {
-        int operationId = super.addOperation(operation);
+        int operationId;
         PreparedStatement stmt = null;
         try {
+            operationId = super.addOperation(operation);
             Connection conn = OperationManagementDAOFactory.getConnection();
             stmt = conn.prepareStatement("INSERT INTO DM_CONFIG_OPERATION(OPERATION_ID, OPERATION_CONFIG) VALUES(?, ?)");
             stmt.setInt(1, operationId);
@@ -59,9 +60,9 @@ public class ConfigOperationDAOImpl extends OperationDAOImpl {
 
     @Override
     public void deleteOperation(int id) throws OperationManagementDAOException {
-        super.deleteOperation(id);
         PreparedStatement stmt = null;
         try {
+            super.deleteOperation(id);
             Connection connection = OperationManagementDAOFactory.getConnection();
             stmt = connection.prepareStatement("DELETE DM_CONFIG_OPERATION WHERE OPERATION_ID = ?") ;
             stmt.setInt(1, id);
@@ -78,8 +79,8 @@ public class ConfigOperationDAOImpl extends OperationDAOImpl {
         PreparedStatement stmt = null;
         ByteArrayOutputStream bao = null;
         ObjectOutputStream oos = null;
-        super.updateOperation(operation);
         try {
+            super.updateOperation(operation);
             Connection connection = OperationManagementDAOFactory.getConnection();
             stmt = connection.prepareStatement("UPDATE DM_CONFIG_OPERATION O SET O.OPERATION_CONFIG = ? " +
                     "WHERE O.OPERATION_ID = ?");
@@ -146,7 +147,6 @@ public class ConfigOperationDAOImpl extends OperationDAOImpl {
                     + operationId, e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return configOperation;
     }
@@ -205,7 +205,6 @@ public class ConfigOperationDAOImpl extends OperationDAOImpl {
                 }
             }
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return operations;
     }

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

@@ -189,7 +189,6 @@ public class OperationDAOImpl implements OperationDAO {
                     "available for the id '" + id, e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return operation;
     }
@@ -229,7 +228,6 @@ public class OperationDAOImpl implements OperationDAO {
                     "available for the device'" + enrolmentId + "' with id '" + operationId, e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return operation;
     }
@@ -271,7 +269,6 @@ public class OperationDAOImpl implements OperationDAO {
                     "available for the device'" + enrolmentId + "' with status '" + status.toString(), e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return operations;
     }
@@ -311,7 +308,6 @@ public class OperationDAOImpl implements OperationDAO {
                     "available for the device'" + enrolmentId + "' with status '", e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return operations;
     }
@@ -350,7 +346,6 @@ public class OperationDAOImpl implements OperationDAO {
             throw new OperationManagementDAOException("Error occurred while adding operation metadata", e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
     }
 
@@ -393,7 +388,6 @@ public class OperationDAOImpl implements OperationDAO {
                     "for the device'" + enrolmentId + "' with status '" + status.toString(), e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return operations;
     }

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

@@ -37,15 +37,15 @@ public class PolicyOperationDAOImpl extends OperationDAOImpl {
 
     @Override
     public int addOperation(Operation operation) throws OperationManagementDAOException {
-        int operationId = super.addOperation(operation);
+        int operationId;
+        PreparedStatement stmt = null;
+        try {
+            operationId = super.addOperation(operation);
             operation.setCreatedTimeStamp(new Timestamp(new java.util.Date().getTime()).toString());
             operation.setId(operationId);
             operation.setEnabled(true);
             PolicyOperation policyOperation = (PolicyOperation) operation;
             Connection conn = OperationManagementDAOFactory.getConnection();
-
-        PreparedStatement stmt = null;
-        try {
             stmt = conn.prepareStatement("INSERT INTO DM_POLICY_OPERATION(OPERATION_ID, OPERATION_DETAILS) " +
                     "VALUES(?, ?)");
             stmt.setInt(1, operationId);
@@ -64,8 +64,8 @@ public class PolicyOperationDAOImpl extends OperationDAOImpl {
         PreparedStatement stmt = null;
         ByteArrayOutputStream bao = null;
         ObjectOutputStream oos = null;
-        super.updateOperation(operation);
         try {
+            super.updateOperation(operation);
             Connection connection = OperationManagementDAOFactory.getConnection();
             stmt = connection.prepareStatement("UPDATE DM_POLICY_OPERATION O SET O.OPERATION_DETAILS=? " +
                     "WHERE O.OPERATION_ID=?");
@@ -101,9 +101,9 @@ public class PolicyOperationDAOImpl extends OperationDAOImpl {
 
     @Override
     public void deleteOperation(int operationId) throws OperationManagementDAOException {
-        super.deleteOperation(operationId);
         PreparedStatement stmt = null;
         try {
+            super.deleteOperation(operationId);
             Connection connection = OperationManagementDAOFactory.getConnection();
             stmt = connection.prepareStatement("DELETE DM_POLICY_OPERATION WHERE OPERATION_ID=?");
             stmt.setInt(1, operationId);
@@ -147,7 +147,6 @@ public class PolicyOperationDAOImpl extends OperationDAOImpl {
                     "object available for the id '" + operationId + "'", e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return policyOperation;
     }
@@ -206,7 +205,6 @@ public class PolicyOperationDAOImpl extends OperationDAOImpl {
                 }
             }
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return operations;
     }

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

@@ -36,17 +36,15 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
     private static final Log log = LogFactory.getLog(ProfileOperationDAOImpl.class);
 
     public int addOperation(Operation operation) throws OperationManagementDAOException {
-
+        PreparedStatement stmt = null;
-        int operationId = super.addOperation(operation);
+        int operationId;
+        try {
+            operationId = super.addOperation(operation);
             operation.setCreatedTimeStamp(new Timestamp(new java.util.Date().getTime()).toString());
             operation.setId(operationId);
             operation.setEnabled(true);
             ProfileOperation profileOp = (ProfileOperation) operation;
             Connection conn = OperationManagementDAOFactory.getConnection();
-
-        PreparedStatement stmt = null;
-
-        try {
             stmt = conn.prepareStatement("INSERT INTO DM_PROFILE_OPERATION(OPERATION_ID, OPERATION_DETAILS) " +
                     "VALUES(?, ?)");
             stmt.setInt(1, operationId);
@@ -62,13 +60,11 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
 
     @Override
     public void updateOperation(Operation operation) throws OperationManagementDAOException {
-
         PreparedStatement stmt = null;
         ByteArrayOutputStream bao = null;
         ObjectOutputStream oos = null;
-        super.updateOperation(operation);
-
         try {
+            super.updateOperation(operation);
             Connection connection = OperationManagementDAOFactory.getConnection();
             stmt = connection.prepareStatement("UPDATE DM_PROFILE_OPERATION O SET O.OPERATION_DETAILS=? " +
                     "WHERE O.OPERATION_ID=?");
@@ -80,7 +76,6 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
             stmt.setBytes(1, bao.toByteArray());
             stmt.setInt(2, operation.getId());
             stmt.executeUpdate();
-
         } catch (SQLException e) {
             throw new OperationManagementDAOException("Error occurred while update operation metadata", e);
         } catch (IOException e) {
@@ -106,10 +101,9 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
 
     @Override
     public void deleteOperation(int id) throws OperationManagementDAOException {
-
-        super.deleteOperation(id);
         PreparedStatement stmt = null;
         try {
+            super.deleteOperation(id);
             Connection connection = OperationManagementDAOFactory.getConnection();
             stmt = connection.prepareStatement("DELETE DM_PROFILE_OPERATION WHERE OPERATION_ID=?");
             stmt.setInt(1, id);
@@ -122,14 +116,12 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
     }
 
     public Operation getOperation(int id) throws OperationManagementDAOException {
-
         PreparedStatement stmt = null;
         ResultSet rs = null;
         ProfileOperation profileOperation = null;
 
         ByteArrayInputStream bais;
         ObjectInputStream ois;
-
         try {
             Connection conn = OperationManagementDAOFactory.getConnection();
             String sql = "SELECT OPERATION_ID, ENABLED, OPERATION_DETAILS FROM DM_PROFILE_OPERATION WHERE OPERATION_ID=?";
@@ -144,24 +136,17 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
                 ois = new ObjectInputStream(bais);
                 profileOperation = (ProfileOperation) ois.readObject();
             }
-
         } catch (IOException e) {
-            String errorMsg = "IO Error occurred while de serialize the profile operation object";
+            throw new OperationManagementDAOException("IO Error occurred while de serialize the profile " +
-            log.error(errorMsg, e);
+                    "operation object", e);
-            throw new OperationManagementDAOException(errorMsg, e);
         } catch (ClassNotFoundException e) {
-            String errorMsg = "Class not found error occurred while de serialize the profile operation object";
+            throw new OperationManagementDAOException("Class not found error occurred while de serialize the " +
-            log.error(errorMsg, e);
+                    "profile operation object", e);
-            throw new OperationManagementDAOException(errorMsg, e);
         } catch (SQLException e) {
-            String errorMsg = "SQL Error occurred while retrieving the command operation object " + "available for " +
+            throw new OperationManagementDAOException("SQL Error occurred while retrieving the command " +
-                    "the id '"
+                    "operation object " + "available for the id '" + id, e);
-                    + id;
-            log.error(errorMsg, e);
-            throw new OperationManagementDAOException(errorMsg, e);
         } finally {
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return profileOperation;
     }
@@ -169,7 +154,6 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
     @Override
     public List<? extends Operation> getOperationsByDeviceAndStatus(int enrolmentId,
             Operation.Status status) throws OperationManagementDAOException {
-
         PreparedStatement stmt = null;
         ResultSet rs = null;
         ProfileOperation profileOperation;
@@ -202,18 +186,14 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
             }
 
         } catch (IOException e) {
-            String errorMsg = "IO Error occurred while de serialize the profile operation object";
+            throw new OperationManagementDAOException("IO Error occurred while de serialize the profile " +
-            log.error(errorMsg, e);
+                    "operation object", e);
-            throw new OperationManagementDAOException(errorMsg, e);
         } catch (ClassNotFoundException e) {
-            String errorMsg = "Class not found error occurred while de serialize the profile operation object";
+            throw new OperationManagementDAOException("Class not found error occurred while de serialize the " +
-            log.error(errorMsg, e);
+                    "profile operation object", e);
-            throw new OperationManagementDAOException(errorMsg, e);
         } catch (SQLException e) {
-            String errorMsg = "SQL error occurred while retrieving the operation available for the device'" + enrolmentId +
+            throw new OperationManagementDAOException("SQL error occurred while retrieving the operation " +
-                    "' with status '" + status.toString();
+                    "available for the device'" + enrolmentId + "' with status '" + status.toString(), e);
-            log.error(errorMsg);
-            throw new OperationManagementDAOException(errorMsg, e);
         } finally {
             if (bais != null) {
                 try {
@@ -230,8 +210,8 @@ public class ProfileOperationDAOImpl extends OperationDAOImpl {
                 }
             }
             OperationManagementDAOUtil.cleanupResources(stmt, rs);
-            OperationManagementDAOFactory.closeConnection();
         }
         return operationList;
     }
+
 }