用swing写一个登录界面,要求:点击按钮能够写出一段sql语句
时间: 2023-07-01 20:23:47 浏览: 46
好的,以下是一个简单的登录界面示例,使用Swing实现:
```java
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class LoginFrame extends JFrame implements ActionListener {
private JTextField usernameField;
private JPasswordField passwordField;
private JButton loginButton;
public LoginFrame() {
setTitle("登录");
setSize(300, 150);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
JPanel panel = new JPanel(new GridLayout(3, 2));
JLabel usernameLabel = new JLabel("用户名:");
usernameField = new JTextField();
JLabel passwordLabel = new JLabel("密码:");
passwordField = new JPasswordField();
loginButton = new JButton("登录");
loginButton.addActionListener(this);
panel.add(usernameLabel);
panel.add(usernameField);
panel.add(passwordLabel);
panel.add(passwordField);
panel.add(new JLabel());
panel.add(loginButton);
setContentPane(panel);
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == loginButton) {
String username = usernameField.getText();
String password = new String(passwordField.getPassword());
String sql = "SELECT * FROM users WHERE username='" + username + "' AND password='" + password + "'";
System.out.println("SQL: " + sql);
}
}
public static void main(String[] args) {
new LoginFrame();
}
}
```
当用户在界面中输入用户名和密码并点击登录按钮后,程序会输出一条SQL语句,格式为:
```
SELECT * FROM users WHERE username='输入的用户名' AND password='输入的密码'
```
这是一个简单的示例,实际应用中需要注意SQL注入等安全问题。