一、安装mysql驱动：

 

二、看数据库中有什么表安装：

文件类写数据库查询：

package hunteronHC;

 

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

 

public class baseServer {

// 连接MySql数据库，用户名和密码都是root

public static final String url = "jdbc:mysql://192.168.50.42:3306/jobhunter_test";

public static final String username = "test";

public static final String password = "test";

 

public static void main(String[] args) {

 

try {

// 1.加载MySql的驱动类

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

// 2.获取数据库链接

try {

Connection con = DriverManager.getConnection(url, username, password);

// 3.创建一个Statement

Statement stmt = con.createStatement();

String query = "select * from online ";

ResultSet re = stmt.executeQuery(query);

while (re.next()) {

System.out.println(re.getString("userId"));

}

} catch (SQLException se) {

System.out.println("数据库连接失败！");

se.printStackTrace();

}

} catch (ClassNotFoundException e) {

System.out.println("找不到驱动程序类 ，加载驱动失败！");

e.printStackTrace();

}

}

 

}