1.导入jar包文件，并添加路径
2.写好配置文件
3.工具类代码JDBCUtils
4.运用

1.导入jar包文件，并添加路径

2.配置文件

c3p0-config.xml
（必须是这个名字！！！！）
在 src 路径下

配置文件代码：

<?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/stus</property>
    <property name="user">root</property>
    <property name="password">1234</property>
    
    
    <property name="initialPoolSize">10</property>
    <property name="maxIdleTime">30</property>
    <property name="maxPoolSize">100</property>
    <property name="minPoolSize">10</property>
    <property name="maxStatements">200</property>
  </default-config>
</c3p0-config>

3.工具类代码

JDBCUtils:

package com.util;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class JDBCUtils {
	
	static ComboPooledDataSource dataSource =null;
	
	static{
		dataSource = new ComboPooledDataSource();
	}
	
	**public static DataSource getDataSource(){
		return dataSource;
	}**
	
	public static Connection getConnection() throws SQLException{
		return dataSource.getConnection();
	}
	
	public static void close(Connection con,Statement stat){
		if(stat != null){
			try{
				stat.close();
			}catch(SQLException ex){};
		}
		if(con != null){
			try{
				con.close();
			}catch(SQLException ex){};
		}}
	public static void close(Connection con,Statement stat,ResultSet rs){
		if(stat != null){
			try{
				stat.close();
			}catch(SQLException ex){};
		}
		if(con != null){
			try{
				con.close();
			}catch(SQLException ex){};
		}
		if(rs != null){
			try{
				rs.close();
			}catch(SQLException ex){};
		}}}

4.运用

QueryRunner runner = new QueryRunner(JDBCUtils.getDataSource());

案例：