init operation mgt data connection

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

@@ -36,6 +36,7 @@ public class OperationManagementDAOFactory {
     private static DataSource dataSource;
     private static final Log log = LogFactory.getLog(OperationManagementDAOFactory.class);
     private static ThreadLocal<Connection> currentConnection = new ThreadLocal<Connection>();
+    private static final Object LOCK = new Object();
 
     public static OperationDAO getCommandOperationDAO() {
         return new CommandOperationDAOImpl();
@@ -60,6 +61,7 @@ public class OperationManagementDAOFactory {
     public static void init(DataSource dtSource) {
         dataSource = dtSource;
     }
+
     public static void init(DataSourceConfig config) {
         dataSource = resolveDataSource(config);
     }
@@ -72,7 +74,18 @@ public class OperationManagementDAOFactory {
         }
     }
 
-    public static Connection getConnection() {
+    public static Connection getConnection() throws OperationManagementDAOException {
+        if (currentConnection.get() == null) {
+            synchronized (LOCK) {
+
+                try {
+                    currentConnection.set(dataSource.getConnection());
+                } catch (SQLException e) {
+                    throw new OperationManagementDAOException("Error occurred while retrieving datasource connection",
+                            e);
+                }
+            }
+        }
         return currentConnection.get();
     }
 

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

@@ -99,6 +99,7 @@ public class CommandOperationDAOImpl extends OperationDAOImpl {
                     "d.DEVICE_IDENTIFICATION = ?) d1 INNER JOIN DM_DEVICE_OPERATION_MAPPING dom ON d1.ID = " +
                     "dom.DEVICE_ID) ois ON o.ID = ois.OP_ID ORDER BY " +
                     "o.CREATED_TIMESTAMP ASC) po ON co.OPERATION_ID = po.OPERATION_ID";
+
             stmt = conn.prepareStatement(sql);
             stmt.setString(1, deviceId.getType());
             stmt.setString(1, deviceId.getId());

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

@@ -24,6 +24,7 @@ import org.wso2.carbon.device.mgt.core.operation.mgt.dao.OperationDAO;
 import org.wso2.carbon.device.mgt.core.operation.mgt.dao.OperationManagementDAOException;
 import org.wso2.carbon.device.mgt.core.operation.mgt.dao.OperationManagementDAOFactory;
 import org.wso2.carbon.device.mgt.core.operation.mgt.dao.OperationManagementDAOUtil;
+
 import java.sql.*;
 import java.util.ArrayList;
 import java.util.Date;
@@ -117,11 +118,12 @@ public class OperationDAOImpl implements OperationDAO {
             Connection conn = OperationManagementDAOFactory.getConnection();
             String sql =
                     "SELECT o.ID, o.TYPE, o.CREATED_TIMESTAMP, o.RECEIVED_TIMESTAMP, o.STATUS FROM DM_OPERATION o " +
-                            "INNER JOIN (SELECT dom.OPERATION_ID AS OP_ID FROM (SELECT d.ID FROM DM_DEVICE d INNER JOIN "
-                            +
-                            "DM_DEVICE_TYPE dm ON d.DEVICE_TYPE_ID = dm.ID AND dm.NAME = ? AND d.DEVICE_IDENTIFICATION = ?) d1 "
-                            +
-                            "INNER JOIN DM_DEVICE_OPERATION_MAPPING dom ON d1.ID = dom.DEVICE_ID) ois ON o.ID = ois.OP_ID";
+                            "INNER JOIN (SELECT dom.OPERATION_ID AS OP_ID FROM (SELECT d.ID FROM DM_DEVICE d INNER " +
+                            "JOIN " +
+                            "DM_DEVICE_TYPE dm ON d.DEVICE_TYPE_ID = dm.ID AND dm.NAME = ? AND d" +
+                            ".DEVICE_IDENTIFICATION = ?) d1 "+
+                            "INNER JOIN DM_DEVICE_OPERATION_MAPPING dom ON d1.ID = dom.DEVICE_ID) ois  " +
+                            "ON o.ID = ois.OP_ID";
             stmt = conn.prepareStatement(sql);
             stmt.setString(1, deviceId.getType());
             stmt.setString(2, deviceId.getId());