JDBC连接池-C3P0连接

JDBC连接池-C3P0连接

c3p0连接池的学习英语好的看英文原版      c3p0 - JDBC3 Connection and Statement Pooling  

使用c3p0连接池  三种方法：1.实例化和配置      ComboPooledDataSource  2.使用DataSource工厂类  3建立自己池数据源

c3p0 是开源免费的连接池

1.实例化和配置      ComboPooledDataSource

在src目录下添加c3p0-config.xml文件

文件名内容为：

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
  <default-config>
    <property name="driverClass">com.mysql.jdbc.Driver</property>
    <property name="jdbcUrl">jdbc:mysql://localhost:3306/bookstore</property>
    <property name="user">root</property>
    <property name="password">root</property>
    <property name="initialPoolSize">5</property>
    <property name="maxPoolSize">20</property>
  </default-config>
  
  <named-config name="bookStore"> 
    <property name="driverClass">com.mysql.jdbc.Driver</property>
    <property name="jdbcUrl">jdbc:mysql://localhost:3306/bookstore</property>
    <property name="user">root</property>
    <property name="password">root</property>
  </named-config>
  
</c3p0-config>

Testc3p0.java

package com.study.jdbc.test;

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




import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import com.study.jdbc.Utils.C3P0Utils;
import com.study.jdbc.Utils.JDBCUtils_V3;

public class TestC3p0 {
    @Test
    public void test1(){
        Connection conn=null;
        PreparedStatement pstm=null;
                //加载c3p0-config.xml文件中默认的config
        ComboPooledDataSource dataSource =new ComboPooledDataSource();
                //加载文件中 <named-config name="bookStore"> </named=config> 的配置信息
        ComboPooledDataSource dataSource1 =new ComboPooledDataSource("bookStore");

            try {
                conn=dataSource.getConnection();
                System.out.println(conn);
                String sql="insert into user values(18,?,?)";
                pstm=conn.prepareStatement(sql);
                pstm.setString(1,"吕布");
                pstm.setString(2,"点错");
                int rows =pstm.executeUpdate();
                if (rows>0) {
                    System.out.println("ok");
                }else {
                    System.out.println("no");
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }finally{
                //dataSource.backConnection(conn);
                JDBCUtils_V3.release(conn,pstm,null);
            }
        
        
    }
}