java 连接数据库

package com.jdbc;

import java.sql.*;
public class JDBCDemo {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        //1.注册驱动
        Class.forName("com.mysql.jdbc.Driver");
        //2.连接
        String url = "jdbc:mysql://localhost:3306/zfj";
        String username = "root";
        String password = "root";
        Connection con = DriverManager.getConnection(url,username,password);
        //3.语句执行对象 (执行sql) 返回值 Statement
        Statement stat = con.createStatement();
        //4.执行sql语句  executeLargeUpdate 用与mysql 中 insert update delete
        //int row = (int) stat.executeLargeUpdate("INSERT INTO user (id,user_name,user_age,user_sex) VALUES ('100','fj','20','1')");


        //查询 select
        String sql = "SELECT * FROM user";
        ResultSet rs = stat.executeQuery(sql);
        //处理结果集
        while (rs.next()){
            //获取每列的的数据
            System.out.println(rs.getString("id")+"  "+rs.getString("user_name")+"  "+rs.getString("user_age")+"  "+rs.getString("user_sex"));
        }



        //5.释放资源
        rs.close();
        stat.close();
        con.close();
    }
}