c3p0 数据连接池 流行开源

注意事项：配置文件规定命名，不能更改   c3p0-config  

<?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/day16</property>
        <property name="user">root</property>
        <property name="password">root</property>
    
        <property name="acquireIncrement">5</property>
        <property name="initialPoolSize">10</property>
        <property name="minPoolSize">5</property>
        <property name="maxPoolSize">20</property>
    </default-config>
    
</c3p0-config>

c3p0数据连接池

package com.itheima.utils;

import java.io.InputStream;
import java.sql.Connection;
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 C3P0Util {

    private static DataSource ds =new ComboPooledDataSource();
    
    /**
     * 用于从池中获取连接
     * @return
     */
    public static synchronized Connection getConneciton(){
        try {
            return ds.getConnection();
        } catch (SQLException e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    
    //关闭资源
    public static void release(ResultSet rs,Statement st,Connection con ){
        try {
            if(rs!=null){
                rs.close();
                rs=null;//目的是让回收器立即进行垃圾回收
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        try {
            if(st!=null){
                st.close();
                st=null;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        try {
            if(con!=null){
                con.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    
    }
}

测试程序

package com.itheima.test;

import java.sql.Connection;
import java.sql.Statement;

import com.itheima.utils.C3P0Util;

public class C3P0Test {

    /**
     * @param args
     */
    public static void main(String[] args) {
        Connection  con = null;
        Statement st = null;
    
        try {
            con =C3P0Util.getConneciton();
            //.....
            st = con.createStatement();
            st.executeUpdate("insert into account values(5,'cgx',100)");
            
            
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            C3P0Util.release(null, st, con);
        }

    }

}