java jdbc 链接mysq 测试l 云服务器 和云数据库 mysql DB

话不多说直接上效果图

下面给出参考代码：

package com.humi.db;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

public class DBTest {

//	public  DBTest(){};

//	public  DBTest(String a){};

	//ip+port

//	static String URL ="jdbc:mysql://119.29.36.221:3306/test";//服务器数据库

	static String URL ="jdbc:mysql://1592ba7b93d216.gz.cdb.myqcloud.com:7107/e_market";//腾讯云数据库

	//uid

	static String userName="root"; //默认root mysql  没有去改她

	//pwd

	static String userPassword="***";	//这里输入自己的密码

	//mysql SQL;

	static String SQL="select * from mysql_user";

	//mysql connection

	static Connection conn =null;

	//prestatement

	static PreparedStatement pst = null;

	//resultSet

	static ResultSet rs = null;

	static {

		try {

			Class.forName("com.mysql.jdbc.Driver");

			System.out.println("驱动加载成功！");

		} catch (ClassNotFoundException e) {

			System.out.println("没有找到驱动！");

			e.printStackTrace();

		}

	}

	public static void conectDB(String URL,String userName,String userPassword){

		try {

			conn = DriverManager.getConnection(URL, userName, userPassword);

			System.out.println("已连接上"+URL+"：\n数据库"+conn);

		} catch (SQLException e) {

			System.out.println("获取链接失败");

			e.printStackTrace();

		}

	}

	public static void querryByid(String SQL){

		try {

			pst = conn.prepareStatement(SQL);

			System.out.println("执行查询语");

			rs = pst.executeQuery();

			while(rs.next()){

				System.out.println("id"+"uname"+"upwd\n"+

						rs.getInt(1)+"\t"+rs.getString(2)+"\t"+rs.getString(3));

			}

		} catch (SQLException e) {

			System.out.println("查询失败");

			e.printStackTrace();

		}

	}

	public static void close(Connection conn,PreparedStatement pst, ResultSet rs){

		if(rs!=null){

			try {

				rs.close();

			} catch (SQLException e) {

				e.printStackTrace();

			}finally{

				if(pst!=null){

					try {

						pst.close();

					} catch (SQLException e) {

						e.printStackTrace();

					}finally{

						if(conn!=null){

							try {

								conn.close();

								System.out.println("数据库链接已关闭，资源已释放");

							} catch (SQLException e) {

								e.printStackTrace();

							}finally{

								conn=null;

								pst= null;

								rs = null;

							}

						}

					}

				}

			}

		}

	}

	public static void main(String[] args) {

		DBTest dbUtil = new DBTest();

		dbUtil.conectDB(URL, userName, userPassword);

		dbUtil.querryByid(SQL);

		dbUtil.close(conn, pst, rs);

	}

}