javaswing语句 java连接mysql,简单登录框实现

DROP TABLE IF EXISTS `table`;
CREATE TABLE `table` (
  `name` char(8) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `password` int DEFAULT NULL,
  PRIMARY KEY (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3;
-- ----------------------------
-- Records of table
-- ----------------------------
INSERT INTO `table` VALUES ('admin', '666');
INSERT INTO `table` VALUES ('gg', '123');
INSERT INTO `table` VALUES ('yy', '123');

package denglu;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement; 
import javax.swing.JOptionPane;
public class dj {
    Connection con = null;
    Statement statement = null;
    ResultSet res = null;
    String driver = "com.mysql.cj.jdbc.Driver";
    String url = "jdbc:mysql://localhost:3306/denglu?useUnicode=true&characterEncoding=UTF-8&serverTimezone=CST";//denglu是自己创的mysql库名
    String name = "root";
    String passwd = "123456";
    public dj() {
        try {
            Class.forName(driver).newInstance();
            con = DriverManager.getConnection(url, name, passwd);
            statement = con.createStatement();
        } catch (ClassNotFoundException e) {
            System.out.println("对不起，找不到这个Driver");
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public boolean compare(String name, String password) {
        boolean m = false;
        String sql = "select password from table where name=\"" + name + "\"";//自己在denglu这个库里面创建table表并写入mysql语句
        System.out.println("sql="+sql);
        try {
            res = statement.executeQuery(sql);
            System.out.println("res="+res);
            if (res.next()) {
                String pa = res.getString(1);
                System.out.println(pa + " " + password);
                if (pa.equals(password)) {
                    m = true;
                } else {
                    JOptionPane.showMessageDialog(null, "密码错误！");
                }
            } else {
                JOptionPane.showMessageDialog(null, "用户名不存在！");
            }
            res.close();
            con.close();
            statement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return m;
    }
}

package denglu;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class dd extends JFrame  {
     JPanel pan = new JPanel();
     JLabel namelab = new JLabel("用户名");
     JLabel passlab = new JLabel("密    码");
    JTextField nametext = new JTextField();
    JPasswordField passtext = new JPasswordField();
    public JButton denglu = new JButton("登录");
    public dd() {
        Font font = new Font("楷体", Font.BOLD, 12);
        super.setTitle("欢迎登录本系统");
        pan.setLayout(null);
        namelab.setBounds(20, 20, 60, 30);
        nametext.setBounds(90, 20, 140, 30);
        passlab.setBounds(20, 60, 60, 30);
        passtext.setBounds(90, 60, 140, 30);
        denglu.setBounds(100, 120, 90, 20);//距离x,距离y,宽，长
        pan.add(namelab);
        pan.add(nametext);
        pan.add(passlab);
        pan.add(passtext);
        pan.add(denglu);
        passtext.setFont(font);
        super.add(pan);
        super.setSize(300, 250);
        super.setVisible(true);
        denglu.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {//监听
               denglu();
            }
        });
    }
    public static void main(String[] args) {
        new dd();//执行布局
    }
    //登录按钮的事件处理函数
    public void denglu() {
        dj dl = new dj();
        String username = nametext.getText();
        String password = passtext.getText();
        if (dl.compare(username, password)) {
            JOptionPane.showMessageDialog(null, "登录成功！");
            super.setVisible(false);
        }
    }
    }