代码1

import com.mysql.jdbc.Driver;
import org.junit.Test;

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

public class Demo7 {
    @Test
    public void test1() throws SQLException {
        //注册驱动
        DriverManager.registerDriver(new Driver());
        //建立连接
        String url="jdbc:mysql://192.168.177.151:4000/test";
        //用户名
        String user="root";
        //密码
        String pwd="123456";
        //获取连接
        Connection connection=DriverManager.getConnection(url,user,pwd);
        //创建命令发送器
        Statement statement=connection.createStatement();
        //准备sql
        String sql="insert into user values(null,'李白','123')";
       //执行sql,获取结果
       int i = statement.executeUpdate(sql);//输出1
       //输出结果
        System.out.println(i);
        //关闭资源
        statement.close();
        connection.close();

    }

    @Test
    public void test2() throws ClassNotFoundException, SQLException {
        //注册驱动
        Class.forName("com.mysql.jdbc.Driver");
        //获取连接
        String url="jdbc:mysql://192.168.177.151:4000/test";
        String user="root";
        String passwd="123456";
        Connection connection=DriverManager.getConnection(url,user,passwd);
        //创建命令发送器
        Statement statement=connection.createStatement();
        //准备sql
        String sql="update user set passwd='456' where id=1";
        //发送sql，获取结果
        int i = statement.executeUpdate(sql);
        System.out.println(i>0?"成功":"失败");
        //关闭资源
        statement.close();
        connection.close();
    }
    
}

代码2