java创建一个计算器窗口

可以参考以下代码实现一个简单的Java计算器窗口：

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

public class Calculator extends JFrame implements ActionListener {

    private JTextField display;
    private JButton[] buttons;
    private String[] buttonLabels = {"7", "8", "9", "/", "4", "5", "6", "*", "1", "2", "3", "-", "0", ".", "=", "+"};
    private double result = 0;
    private String operator = "";
    private boolean startOfNumber = true;

    public Calculator() {
        setTitle("Calculator");
        setSize(300, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        createComponents();
        setVisible(true);
    }

    private void createComponents() {
        display = new JTextField();
        display.setEditable(false);
        add(display, BorderLayout.NORTH);

        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new GridLayout(4, 4));

        buttons = new JButton[buttonLabels.length];
        for (int i = 0; i < buttonLabels.length; i++) {
            buttons[i] = new JButton(buttonLabels[i]);
            buttons[i].addActionListener(this);
            buttonPanel.add(buttons[i]);
        }

        add(buttonPanel, BorderLayout.CENTER);
    }

    public void actionPerformed(ActionEvent event) {
        String command = event.getActionCommand();

        if (command.equals("+")) {
            calculate();
            operator = "+";
            startOfNumber = true;
        } else if (command.equals("-")) {
            calculate();
            operator = "-";
            startOfNumber = true;
        } else if (command.equals("*")) {
            calculate();
            operator = "*";
            startOfNumber = true;
        } else if (command.equals("/")) {
            calculate();
            operator = "/";
            startOfNumber = true;
        } else if (command.equals("=")) {
            calculate();
            display.setText(String.valueOf(result));
            operator = "";
            startOfNumber = true;
        } else if (command.equals(".")) {
            if (startOfNumber) {
                display.setText("0.");
                startOfNumber = false;
            } else if (display.getText().indexOf(".") == -1) {
                display.setText(display.getText() + ".");
            }
        } else {
            display.setText(display.getText() + command);
            startOfNumber = false;
        }
    }

    private void calculate() {
        if (operator.equals("+")) {
            result += Double.parseDouble(display.getText());
        } else if (operator.equals("-")) {
            result -= Double.parseDouble(display.getText());
        } else if (operator.equals("*")) {
            result *= Double.parseDouble(display.getText());
        } else if (operator.equals("/")) {
            result /= Double.parseDouble(display.getText());
        } else {
            result = Double.parseDouble(display.getText());
        }
    }

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

这个计算器窗口使用了JFrame作为主窗口，JTextField作为显示屏幕，JPanel和GridLayout布局来创建按钮。实现了基本的加、减、乘、除和等于操作。