$.DeviceTypeDAO.java Source code

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Here is the source code for $.DeviceTypeDAO.java

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    /*
     * Copyright (c) 2016, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
     *
     * WSO2 Inc. licenses this file to you under the Apache License,
     * Version 2.0 (the "License"); you may not use this file except
     * in compliance with the License.
     * You may obtain a copy of the License at
     *
     * http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing,
     * software distributed under the License is distributed on an
     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     * KIND, either express or implied. See the License for the
     * specific language governing permissions and limitations
     * under the License.
     */

package ${groupId}.${rootArtifactId}.plugin.impl.dao;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;

import ${groupId}.${rootArtifactId}.plugin.constants.DeviceTypeConstants;
import ${groupId}.${rootArtifactId}.plugin.impl.dao.impl.DeviceTypeDAOImpl;
import ${groupId}.${rootArtifactId}.plugin.exception.DeviceMgtPluginException;

    import javax.naming.Context;
    import javax.naming.InitialContext;
    import javax.naming.NamingException;
    import javax.sql.DataSource;
    import java.sql.Connection;
    import java.sql.SQLException;

    public class DeviceTypeDAO {

        private static final Log log = LogFactory.getLog(DeviceTypeDAO.class);
        static DataSource dataSource; // package local variable
        private static ThreadLocal<Connection> currentConnection = new ThreadLocal<>();

        public DeviceTypeDAO() {
            initDeviceTypeDAO();
        }

        public static void initDeviceTypeDAO() {
            try {
                Context ctx = new InitialContext();
                dataSource = (DataSource) ctx.lookup(DeviceTypeConstants.DATA_SOURCE_NAME);
            } catch (NamingException e) {
                log.error("Error while looking up the data source: " + DeviceTypeConstants.DATA_SOURCE_NAME);
            }
        }

        public static void beginTransaction() throws DeviceMgtPluginException {
            try {
                Connection conn = dataSource.getConnection();
                conn.setAutoCommit(false);
                currentConnection.set(conn);
            } catch (SQLException e) {
                throw new DeviceMgtPluginException("Error occurred while retrieving datasource connection", e);
            }
        }

        public static Connection getConnection() throws DeviceMgtPluginException {
            if (currentConnection.get() == null) {
                try {
                    currentConnection.set(dataSource.getConnection());
                } catch (SQLException e) {
                    throw new DeviceMgtPluginException("Error occurred while retrieving data source connection", e);
                }
            }
            return currentConnection.get();
        }

        public static void commitTransaction() throws DeviceMgtPluginException {
            try {
                Connection conn = currentConnection.get();
                if (conn != null) {
                    conn.commit();
                } else {
                    if (log.isDebugEnabled()) {
                        log.debug("Datasource connection associated with the current thread is null, hence commit "
                                + "has not been attempted");
                    }
                }
            } catch (SQLException e) {
                throw new DeviceMgtPluginException("Error occurred while committing the transaction", e);
            } finally {
                closeConnection();
            }
        }

        public static void closeConnection() throws DeviceMgtPluginException {

            Connection con = currentConnection.get();
            if (con != null) {
                try {
                    con.close();
                } catch (SQLException e) {
                    log.error("Error occurred while close the connection");
                }
            }
            currentConnection.remove();
        }

        public static void rollbackTransaction() throws DeviceMgtPluginException {
            try {
                Connection conn = currentConnection.get();
                if (conn != null) {
                    conn.rollback();
                } else {
                    if (log.isDebugEnabled()) {
                        log.debug("Datasource connection associated with the current thread is null, hence rollback "
                                + "has not been attempted");
                    }
                }
            } catch (SQLException e) {
                throw new DeviceMgtPluginException("Error occurred while rollback the transaction", e);
            } finally {
                closeConnection();
            }
        }

        public DeviceTypeDAOImpl getDeviceTypeDAO() {
            return new DeviceTypeDAOImpl();
        }
    }