给我用java做一个计算器窗口

好的，以下是一个简单的计算器窗口的Java代码：

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;
    private String operator;

    public Calculator() {
        setTitle("Calculator");
        setLayout(new BorderLayout());

        display = new JTextField("0");
        display.setEditable(false);
        add(display, BorderLayout.NORTH);

        JPanel buttonPanel = new JPanel(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);

        setSize(300, 300);
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public void actionPerformed(ActionEvent e) {
        String label = e.getActionCommand();

        if (label.equals("C")) {
            result = 0;
            operator = "";
            display.setText("0");
        } else if (label.equals("/")) {
            result = Double.parseDouble(display.getText());
            operator = "/";
            display.setText("");
        } else if (label.equals("*")) {
            result = Double.parseDouble(display.getText());
            operator = "*";
            display.setText("");
        } else if (label.equals("-")) {
            result = Double.parseDouble(display.getText());
            operator = "-";
            display.setText("");
        } else if (label.equals("+")) {
            result = Double.parseDouble(display.getText());
            operator = "+";
            display.setText("");
        } else if (label.equals("=")) {
            double secondOperand = Double.parseDouble(display.getText());
            if (operator.equals("/")) {
                result /= secondOperand;
            } else if (operator.equals("*")) {
                result *= secondOperand;
            } else if (operator.equals("-")) {
                result -= secondOperand;
            } else if (operator.equals("+")) {
                result += secondOperand;
            }
            display.setText("" + result);
        } else {
            String text = display.getText();
            if (text.equals("0")) {
                display.setText(label);
            } else {
                display.setText(text + label);
            }
        }
    }

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

这个计算器窗口可以进行基本的加减乘除运算。你可以根据需要进行修改和优化。