江苏开放大学软件设计模式与体系结构综合大作业

DROP DATABASE IF EXISTS sms;

/*=============创建数据库=============*/

CREATE DATABASE sms;

/*=============使用数据库=============*/

USE sms;

/*=============删除数据库表===========*/

DROP TABLE IF EXISTS user;

/*=============创建数据库表===========*/

CREATE TABLE login(

id int NOT NULL primary key auto_increment,

username VARCHAR(30) NOT NULL,

password VARCHAR(32) NOT NULL

);

INSERT INTO login( username, password)VALUES(‘admin’, ‘123456’);

import javax.swing.*;

import java.awt.event.*;

import java.sql.*;

public class LoginDialog extends JDialog{

private JPanel contentPane;

private JButton buttonOK;

private JButton buttonCancel;

private JLabel lblUserName;

private JLabel lblPassword;

private JTextField tfPassword;

private JTextField tfUserName;

public LoginDialog() {

this.setSize(500, 450);

contentPane = new JPanel();

contentPane.setLayout(null);

lblUserName = new JLabel(“用户名:”);

lblUserName.setSize(50, 40);

lblUserName.setLocation(50, 50);

tfUserName = new JTextField();

tfUserName.setSize(250, 40);

tfUserName.setLocation(150, 50);

lblPassword = new JLabel(“密码:”);

lblPassword.setSize(50, 40);

lblPassword.setLocation(50, 150);

tfPassword = new JPasswordField();

tfPassword.setSize(250, 40);

tfPassword.setLocation(150, 150);

buttonOK = new JButton(“登录”);

buttonOK.setSize(80, 40);

buttonOK.setLocation(130, 250);

buttonCancel = new JButton(“取消”);

buttonCancel.setSize(80, 40);

buttonCancel.setLocation(280, 250);

contentPane.add(lblUserName);

contentPane.add(tfUserName);

contentPane.add(lblPassword);

contentPane.add(tfPassword);

contentPane.add(buttonOK);

contentPane.add(buttonCancel);

setContentPane(contentPane);

setModal(true);

getRootPane().setDefaultButton(buttonOK);

buttonOK.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

onOK();

}

});

buttonCancel.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

onCancel();

}

});

// call onCancel() when cross is clicked

setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);

addWindowListener(new WindowAdapter() {

@Override

public void windowClosing(WindowEvent e) {

onCancel();

}

});

}

private void onOK() {

Connection conn = getConnection();

String username = tfUserName.getText();

String password = tfPassword.getText();

String result = login(conn, username, password);

JOptionPane.showMessageDialog(null, result);

}

private void onCancel() {

dispose();

}

private Connection getConnection() {

Connection connection = null;

try {

Class.forName(“com.mysql.cj.jdbc.Driver”); // 加载驱动程序

connection = DriverManager.getConnection(

“jdbc:mysql://localhost:3306/sms”,

“root”, “Succld3388”); // 取得数据库连接

} catch (SQLException | ClassNotFoundException e) {

e.printStackTrace();

}

return connection;

}

/**

* 具体操作方法：查询

*/

public String login(Connection conn, String userName, String password){

String result = null;

try{

String sql = “SELECT username, password FROM login WHERE username = ?”;

PreparedStatement pstmt = null; //定义数据库操作对象

pstmt = conn.prepareStatement(sql); // 实例化操作

pstmt.setString(1, userName); // 设置用户名称

ResultSet rs = pstmt.executeQuery(); // 取得查询结果

if(rs.next()){

String pass = rs.getString(2);

if (pass.equals(password)){

result = “登录成功”;

}else{

result = “密码错误”;

}

}else{

result = “用户名不正确”;

}

}catch(Exception e){

result = “数据库错误”;

}

return result;

}

public static void main(String[] args) {

LoginDialog dialog = new LoginDialog();

dialog.setLocationRelativeTo(null);

dialog.setVisible(true);

System.exit(0);

}

}