Java를 사용하여 간단한 GUI 애플리케이션을 개발하는 방법

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Calculator extends JFrame {
    private JTextField textField;
    private JButton button1;
    private JButton button2;
    // ...
    private JButton button9;
    private JButton buttonAdd;
    private JButton buttonSubtract;
    // ...
    private JButton buttonEquals;

    public Calculator() {
        super("Simple Calculator");
 
        // 设置窗口的大小和布局
        setSize(300, 400);
        setLayout(new BorderLayout());
 
        // 创建文本框和标签
        textField = new JTextField();
        JLabel label = new JLabel("Calculator");
 
        // 创建按钮
        button1 = new JButton("1");
        button2 = new JButton("2");
        // ...
        button9 = new JButton("9");
        buttonAdd = new JButton("+");
        buttonSubtract = new JButton("-");
        // ...
        buttonEquals = new JButton("=");
 
        // 添加组件到窗口中
        add(label, BorderLayout.NORTH);
        add(textField, BorderLayout.CENTER);
        add(button1);
        add(button2);
        // ...
        add(button9);
        add(buttonAdd);
        add(buttonSubtract);
        // ...
        add(buttonEquals, BorderLayout.SOUTH);
 
        // 设置按钮的监听器
        button1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "1");
            }
        });
        button2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "2");
            }
        });
        // ...
        button9.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "9");
            }
        });
        buttonAdd.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "+");
            }
        });
        buttonSubtract.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "-");
            }
        });
        // ...
        buttonEquals.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String expression = textField.getText();
                // 进行计算并在文本框中显示结果
                textField.setText(calculate(expression));
            }
        });
 
        // 设置窗口可见
        setVisible(true);
    }

    // 实现计算逻辑
    private String calculate(String expression) {
        // TODO: 实现计算逻辑
        return "";
    }
 
    public static void main(String[] args) {
        new Calculator();
    }
}

public static void main(String[] args) {
    new Calculator();
}