使用C3P0连接池

jar包地址
配置文件
源码
1：导入配置文件

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>

  <default-config>
    <property name="driverClass">com.mysql.jdbc.Driver</property>
    <property name="jdbcUrl">jdbc:mysql:///web08</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="itheima"> 
   <property name="driverClass">com.mysql.jdbc.Driver</property>
    <property name="jdbcUrl">jdbc:mysql:///web08</property>
    <property name="user">root</property>
    <property name="password">root</property>
  </named-config>


</c3p0-config>

2：编写C3P0工具类

package cn.itheima.jdbc.utils;

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

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class C3P0Utils {

    private static ComboPooledDataSource database = new ComboPooledDataSource();

    public static DataSource getDataSource(){
        return database;
    }

    public static Connection getConnection(){
        try {
            return database.getConnection();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }


}

3：编写测试类

package cn.itheima.jdbc.test;

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

import javax.sql.DataSource;

import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;

import cn.itheima.jdbc.utils.C3P0Utils;
import cn.itheima.jdbc.utils.JDBCUtils_V3;

public class TestC3P0 {

    @Test
    public void addUser(){
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            //2.从池子中获取连接
            conn = C3P0Utils.getConnection();
            String sql = "insert into tbl_user values(null,?,?)";
            //必须在自定义的Connection类中重写prepareStatement(sql)方法
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, "吕布2");
            pstmt.setString(2, "貂蝉2");
            int rows = pstmt.executeUpdate();
            if(rows>0){
                System.out.println("添加成功");
            }else {
                System.out.println("添加失败");
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            JDBCUtils_V3.release(conn, pstmt, null);
        }
    }

}