jmsbasicdatasource.java

Java Mail Server JAVA编写的邮件服务器

/****************************************************************
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.     *
 *                                                              *
 * Copyright 2008 Jun Li(SiChuan University, the School of      *
 * Software Engineering). All rights reserved.                  *
 *                                                              *
 * Licensed to the JMS under one  or more contributor license   *
 * agreements.  See the LICENCE file  distributed with this     *
 * work for additional information regarding copyright          *
 * ownership.  The JMS licenses this file  you may not use this *
 * file except in compliance  with the License.                 *
 *                                                              *
 * 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 org.jpxx.mail.Service;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Date;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.log4j.Logger;
import org.jpxx.mail.Constants;
import org.jpxx.mail.Factory;

/**
 *
 * @author Jun Li
 * @version 0.0.3, Date: 2008/05/14
 */
public class JMSBasicDataSource {

    private static JMSBasicDataSource singletonInstance = null;
    private static BasicDataSource ds = null;
    /**
     * Creates an instance of Logger and initializes it. 
     * It is to write log for <code>JMSBasicDataSource</code>.
     */
    private Logger log = Factory.getSingletonInstance().getLogger(this);

    private JMSBasicDataSource() {
        File f = new File(Constants.DBCP_CONFIG_FILE_PATH);
        if (!f.exists()) {
            log.error(Constants.DBCP_CONFIG_FILE_PATH +
                    " Not Exist,system will create it." +
                    " Please edit this config file and then restart server.");
            try {
                f.createNewFile();
                FileWriter fw = new FileWriter(f);
                fw.write("#This config file is to support database\r\n");
                fw.write("#@since version 0.0.3\r\n");
                fw.write("#@author Jun Li\r\n");
                fw.write("#Create date:" + new Date() + "\r\n");
                fw.write("\r\n");
                fw.write("#Database driver\r\n");
                fw.write("#Example: driver=com.mysql.jdbc.Driver\r\n");
                fw.write("driver=com.mysql.jdbc.Driver\r\n");
                fw.write("#The database user\r\n");
                fw.write("#Example: user=root\r\n");
                fw.write("user=root\r\n");
                fw.write("#Database use's password\r\n");
                fw.write("pass=\r\n");
                fw.write("#The database url\r\n");
                fw.write("#Example: url=jdbc:mysql://[host][,failoverhost...]" +
                        "[:port]/[database][?propertyName1][=propertyValue1]" +
                        "[&propertyName2][=propertyValue2]...\r\n");
                fw.write("url=jdbc:mysql://127.0.0.1:3306/jms\r\n");
                fw.close();
            } catch (IOException e) {
                log.error(e);
            }
            System.exit(-1);
        } else {
            Properties p = new Properties();
            try {
                p.load(new FileInputStream(Constants.DBCP_CONFIG_FILE_PATH));
                ds = new BasicDataSource();
                String url = p.getProperty("url");
                String user = p.getProperty("user");
                String pass = p.getProperty("pass");
                String driver = p.getProperty("driver");

                ds.setDriverClassName(driver);
                ds.setUsername(user);
                ds.setPassword(pass);
                ds.setUrl(url);
            } catch (IOException e) {
                log.error(e);
            }
        }
    }

    /**
     * Gets singleton instance of JMSBasicDataSource
     * @return Singleton Instance of JMSBasicDataSource
     */
    public static JMSBasicDataSource getSingletonInstance() {
        if (singletonInstance == null) {
            singletonInstance = new JMSBasicDataSource();
        }
        return singletonInstance;
    }

    /**
     * Gets BasicDataSource
     * @return DataSource
     */
    public DataSource getDataSource() {
        if (ds == null) {
            log.error("Please edit the " + Constants.DBCP_CONFIG_FILE_PATH +
                    " config file and then restart server.");
        }
        return ds;
    }
}