数据库连接池c3p0基本使用和配置演示

c3p0：数据库连接池技术
步骤：
导入jar包(两个) c3p0-0.9.5.2.jar mchange-commons-java-0.2.12.jar
不要忘记导入数据库驱动jar包
定制配置文件：
名称：c3p0.properties或者c390-config.xml
路径：直接将文件放在src目录下即可
创建核心对象 数据库连接池对象 ComboPooledDataSource

c3p0-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
    <default-config>
        <property name="user">root</property>
        <property name="password">root</property>
        <property name="driverClass">com.mysql.jdbc.Driver</property>
        <property name="jdbcUrl">jdbc:mysql:///root</property>
    </default-config><!-- This app is massive! -->
</c3p0-config>

/**
 * c3p0演示
 */
public class C3P0Demo1 {
    public static void main(String[] args) throws SQLException {
        //创建数据库连接池对象
        DataSource ds = new ComboPooledDataSource();
        //获取连接对象
        Connection conn = ds.getConnection();

        System.out.println(conn);
    }
}

package cn.itcust.datasource.c3p0;


import com.mchange.v2.c3p0.ComboPooledDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

public class C3P0Demo2 {
    public static void main(String[] args) throws SQLException {
        //获取DataSource
        DataSource ds = new ComboPooledDataSource();
        //获取连接
        for (int i = 0; i < 10; i++) {
            Connection conn = ds.getConnection();
            System.out.println(i+"-->"+conn);
        }
    }
}

package cn.itcust.datasource.c3p0;


import com.mchange.v2.c3p0.ComboPooledDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

public class C3P0Demo2 {
    public static void main(String[] args) throws SQLException {
        //获取DataSource
        DataSource ds = new ComboPooledDataSource();
        //获取连接
        for (int i = 0; i < 10; i++) {
            Connection conn = ds.getConnection();
            System.out.println(i+"-->"+conn);

            if (i == 5) {
                conn.close();//归还连接导连接池中
            }
        }
    }
}