day18 17.c3p0连接池使用

连接池时间长不用空闲着,dbcp是不回收的，性能可能有些问题。c3p0是可以自动回收。实际开发中c3p的生产力比dbcp强，性能上更强。

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package cn.itcast.datasource;

import java.beans.PropertyVetoException;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.SQLException;

import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class C3p0Test {

    //手动

    @Test

    public void test1() throws PropertyVetoException, SQLException{

        ComboPooledDataSource cpds = new ComboPooledDataSource();

        cpds.setDriverClass("com.mysql.jdbc.driver");

        cpds.setJdbcUrl("jdbc:mysql:///day18");

        cpds.setUser("root");

        cpds.setPassword("");

        //得到一个Connection

        Connection con = cpds.getConnection();

        ResultSet rs= con.createStatement().executeQuery("select * from account");

        while(rs.next()){

            System.out.println(rs.getInt("id")+"   "+rs.getString("name"));

        }

    rs.close();

    con.close();//将Connection对象重新装入到连接池.

    }

    @Test

    public void test2() throws SQLException{

        ComboPooledDataSource cpds = new ComboPooledDataSource();

        //得到一个Connection

        Connection con = cpds.getConnection();

        ResultSet rs= con.createStatement().executeQuery("select * from account");

        while(rs.next()){

            System.out.println(rs.getInt("id")+"   "+rs.getString("name"));

        }

    rs.close();

    con.close();//将Connection对象重新装入到连接池.

    String path= this.getClass().getResource("/").getPath();

    System.out.println(path);//你在搜索时肯定能找到这个路径嘛 c3p0的底层直接找classpath路径 然后去找指定名称文件  名称是固定的

    }

}

<?xml version="1.0" encoding="UTF-8"?>

<c3p0-config>

  <default-config>

    <property name="driverClass">com.mysql.jdbc.Driver</property>

    <property name="jdbcUrl">jdbc:mysql:///day18</property>

    <property name="user">root</property>

    <property name="password"></property>

  </default-config>

</c3p0-config>