connectionfactory.java

JSP+JavaBean+Servlet 办公自动化管理系统由前台管理和后台管理两大部分组成。 前台管理模块实现：公告管理、公文管理、员工管理、部门信息、收发信息和优秀员工管理6部分。 后台管理

package oa.sys;

import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.sql.Connection;
import java.util.Properties;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;

public class ConnectionFactory {
	private static DataSource dsCache = null;
	private static Properties prop = new Properties();
	private static Object lock = new Object();
	public static int error=0;
	public static Connection getConnection() throws Exception{
		if(dsCache == null){
			synchronized(lock){
				if(dsCache == null){
					prop.load(new FileInputStream("dbsource"));
					Context context = new InitialContext();
					dsCache = (DataSource) context.lookup(prop.getProperty("key"));
				}
			}
			PrintWriter log = new PrintWriter(new FileWriter("connection.log",true));
			log.println(new java.util.Date() + ":当前方法名如getConnectio():"
                    + sun.reflect.Reflection.getCallerClass(2));
			log.close();		
		}
		System.err.println();
		System.err.println("数据连接+"+(++error));
		Connection con = dsCache.getConnection();
		return con;
	}
	public static Connection getConnection(String source) throws Exception{
		if(dsCache == null){
			synchronized(lock){
				if(dsCache == null){
					Context context = new InitialContext();
					dsCache = (DataSource) context.lookup(source);
				}
			}
			PrintWriter log = new PrintWriter(new FileWriter("connection.log",true));
			log.println(new java.util.Date() + ":当前方法名如getConnectio():"
                    + sun.reflect.Reflection.getCallerClass(2));
			log.flush();
			log.close();
		}
		System.err.println();
		System.err.println("数据连接+"+(++error));
		Connection con = dsCache.getConnection();
		return con;
	}
}