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代码示例：

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

public class Calculator extends JFrame {
    private JTextField displayField;
    private double num1, num2, result;
    private String operator;

    public Calculator() {
        super("Calculator");

        // 创建显示文本框
        displayField = new JTextField(10);
        displayField.setEditable(false);
        add(displayField, BorderLayout.NORTH);

        // 创建数字按钮
        JPanel buttonPanel = new JPanel(new GridLayout(4, 4));
        String[] buttonLabels = {"7", "8", "9", "/", "4", "5", "6", "*", "1", "2", "3", "-", "0", ".", "=", "+"};
        for (String label : buttonLabels) {
            JButton button = new JButton(label);
            button.addActionListener(new ButtonListener());
            buttonPanel.add(button);
        }
        add(buttonPanel, BorderLayout.CENTER);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);
    }

    private class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            String buttonLabel = e.getActionCommand();

            // 处理数字输入
            if (buttonLabel.matches("[0-9.]")) {
                displayField.setText(displayField.getText() + buttonLabel);
            }
            // 处理运算符输入
            else if (buttonLabel.matches("[/*\\-+]=?")) {
                if (operator == null) {
                    num1 = Double.parseDouble(displayField.getText());
                    operator = buttonLabel;
                    displayField.setText("");
                } else {
                    num2 = Double.parseDouble(displayField.getText());
                    result = calculate(num1, num2, operator);
                    operator = buttonLabel;
                    num1 = result;
                    displayField.setText(String.valueOf(result));
                }
            }
        }

        private double calculate(double num1, double num2, String operator) {
            switch (operator) {
                case "/":
                    return num1 / num2;
                case "*":
                    return num1 * num2;
                case "-":
                    return num1 - num2;
                case "+":
                    return num1 + num2;
                default:
                    throw new IllegalArgumentException("Invalid operator: " + operator);
            }
        }
    }

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

这个计算器窗口包括一个文本框和数字按钮和运算符按钮，可以进行加、减、乘、除以及小数点的输入和计算。当用户输入数字和运算符时，程序会根据输入的内容进行相应的计算，并在文本框中显示结果。