package c3p0.connection;

import java.beans.PropertyVetoException;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class ConnectionManager {
	private static DataSource data_source=null;;
	private static Properties props=null;
	private static String porps_name=null;
	
	/**
	 * 创建数据库连接池
	 * @return
	 */
	private static DataSource createDataSource(){
		load();
		data_source=initDB();
		return data_source;
	}
		
	/**
	 * 加载配置文件
	 */
	private static void load(){
		try {
			props =  new Properties();
			InputStream in=Thread.currentThread().getContextClassLoader().getResourceAsStream(porps_name);
			props.load(in);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 初始化数据库
	 */
	private static  DataSource initDB(){
		System.out.println("开始初始化数据源...");
		ComboPooledDataSource pool_ds=new ComboPooledDataSource();
		try {
			pool_ds.setDriverClass(getProperty("c3p0.connection.driverClass"));
		} catch (PropertyVetoException e) {
			e.printStackTrace();
			throw new RuntimeException("数据库驱动加载失败");
		}
		pool_ds.setJdbcUrl(getProperty("c3p0.connection.url"));
		pool_ds.setUser(getProperty("c3p0.connection.user"));
		pool_ds.setPassword(getProperty("c3p0.connection.password"));
		pool_ds.setInitialPoolSize(Integer.parseInt(getProperty("c3p0.connection.initialPoolSize")));
		pool_ds.setMaxPoolSize(Integer.parseInt(getProperty("c3p0.connection.maxPoolSize")));
		pool_ds.setMinPoolSize(Integer.parseInt(getProperty("c3p0.connection.minPoolSize")));
		pool_ds.setMaxIdleTime(Integer.parseInt(getProperty("c3p0.connection.maxIdleTime")));
		pool_ds.setAcquireIncrement(Integer.parseInt(getProperty("c3p0.connection.acquireIncrement")));
		pool_ds.setAcquireRetryAttempts(Integer.parseInt(getProperty("c3p0.connection.acquireRetryAttempts")));
		pool_ds.setAcquireRetryDelay(Integer.parseInt(getProperty("c3p0.connection.acquireRetryDelay")));
		pool_ds.setTestConnectionOnCheckout(Boolean.parseBoolean(getProperty("c3p0.connection.testConnectionOnCheckout")));
		pool_ds.setTestConnectionOnCheckin(Boolean.parseBoolean(getProperty("c3p0.connection.testConnectionOnCheckin")));
		pool_ds.setIdleConnectionTestPeriod(Integer.parseInt(getProperty("c3p0.connection.idleConnectionTestPeriod")));
		pool_ds.setCheckoutTimeout(Integer.parseInt(getProperty("c3p0.connection.checkoutTimeout")));
		pool_ds.setAutomaticTestTable(getProperty("c3p0.connection.automaticTestTable"));
		
		System.out.println("数据源初始化完毕...");
		return pool_ds;
	}
	
	/**
	 * 获取c3p0连接池文件配置信息
	 * @param key
	 * @return
	 */
	private static String getProperty(String key){
		if(key==null||"".equals(key)){
			throw new NullPointerException("key不能为空!!!请检查key的赋值!!!");
		}
		return props.getProperty(key);
	}
	
	public static Connection getConnection() throws SQLException{
		data_source=(data_source==null) ? createDataSource() : data_source;
		return data_source.getConnection();
	}
	
	public static void start(String porps_name) throws SQLException{
		ConnectionManager.porps_name=porps_name;
		Connection conn=getConnection();
		conn.close();
	}
	
	public static void stop(){
		data_source=null;
	}
	
	public static void release(Connection conn,PreparedStatement pstmt,ResultSet res){
			try {
				if(conn!=null){
					conn.close();
				}
				if(pstmt!=null){
					pstmt.close();
				}
				if(res!=null){
					res.close();
				}
			} catch (SQLException e) {
				
				e.printStackTrace();
			}
		
	}
	
}

package mystruts.listener;

import java.sql.SQLException;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import c3p0.connection.ConnectionManager;

/**
 * ServletContext 上下文监听器
 * 应用服务器一启动就产生该对象，服务器关闭即销毁
 * 作用于全局，所有Servlet ,相当于静态变量
 * @author tianly
 *
 */
public class ServletContextListen implements ServletContextListener {
	/**
	 * web服务器关闭时执行
	 */
	@Override
	public void contextDestroyed(ServletContextEvent event) {
		/**
		 * 关闭数据源
		 */
		ConnectionManager.stop();
	}
	
	
	/**
	 * web服务器启动时执行
	 */
	@Override
	public void contextInitialized(ServletContextEvent event) {
		
		/**
		 * 初始化数据源
		 */
		String db_url=event.getServletContext().getInitParameter("DataBaseConfig");
		try {
			ConnectionManager.start(db_url);
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

}

package test.c3p0;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import c3p0.connection.ConnectionManager;
import c3p0.util.DateUtil;

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		String currdate=DateUtil.getDateTime();
		Connection conn=null;
		PreparedStatement pstmt=null;
		ResultSet res=null;
		try {
			String sql="insert into userinfo(username,password,sex,regdate) values(?,?,?,?)";
			String sql4ID="select LAST_INSERT_ID()";
			conn=ConnectionManager.getConnection();
			conn.setAutoCommit(false);
			pstmt=conn.prepareStatement(sql);
			pstmt.setString(1, "tly");
			pstmt.setString(2, "tly");
			pstmt.setInt(3, 0);
			pstmt.setString(4, currdate);	//mysql中无需进行日期格式转换
			
			pstmt.executeUpdate();
			pstmt=conn.prepareStatement(sql4ID);
			res=pstmt.executeQuery();
			if(res.next()){
				int ID=res.getInt(1);
				System.out.println("ID："+ID);
			}
			conn.commit();
		} catch (SQLException e) {
			e.printStackTrace();
			try {
				conn.rollback();
			} catch (SQLException e1) {
				e1.printStackTrace();
			}
		}finally{
			ConnectionManager.release(conn, pstmt, res);
		}

	}

}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>mysystem</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
 
  
  <!-- 登录Servlet配置
  <servlet>
  	<servlet-name>LoginServlet</servlet-name>
  	<servlet-class>login.LoginServlet</servlet-class>
  </servlet>
  <servlet-mapping>
  	<servlet-name>LoginServlet</servlet-name>
  	<url-pattern>/login</url-pattern>
  </servlet-mapping> -->
  
  <filter>
  	<filter-name>ActionDispatcher</filter-name>
  	<filter-class> mystruts.actionfilter.ActionDispatcher</filter-class>
  </filter>
  
   <filter-mapping>
  	<filter-name>ActionDispatcher</filter-name>
  	<url-pattern>*.action</url-pattern>
  </filter-mapping>
  
  <!-- 数据库信息配置 -->
  <context-param>
  	<param-name>DataBaseConfig</param-name>
  	<param-value>c3p0/c3p0.properties</param-value>
  </context-param>
  <listener>
  	<listener-class>mystruts.listener.ServletContextListen</listener-class>
  </listener>
  
  
  
  
</web-app>