Java连接Mysql数据库

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

/**
* Java 连接数据库   1.导入jar包
*                 2.配置connection
*                 3.关流
*                 其中标准化代码利用try{}catch{}finally{}处理异常
* @author LENOVO
*
*/
public class Demo_4 {

/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {

Connection con = null;
try{
/*
* 1.四大连接参数
*/
String driverClassName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/stdb";
String username = "root";
String password = "wlg";

/*
* 2.加载驱动类
*/
Class.forName(driverClassName);

/*
* 3.调用DriverManager的getConnection()得到con
*/
con = DriverManager.getConnection(url, username, password);

System.out.println(con);

}catch(Exception e){
throw new RuntimeException(e);
}finally{
/*
* 4.关闭流
*/
if(con != null) con.close();
}
}
}