用java编写一个简易的计算器，要求能进行加减乘除运算，通过鼠标点击按键交互，并使用边界布局

以下是一个使用边界布局的简易计算器示例代码，可以进行加减乘除运算：

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 num1, num2, result;
    private String operator;

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

        // 初始化组件
        display = new JTextField(20);
        display.setEditable(false);
        display.setHorizontalAlignment(SwingConstants.RIGHT);

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

        // 设置布局
        Container container = getContentPane();
        container.setLayout(new BorderLayout(5, 5));
        container.add(display, BorderLayout.NORTH);

        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new GridLayout(4, 4, 5, 5));
        for (int i = 0; i < buttonLabels.length; i++) {
            buttonPanel.add(buttons[i]);
        }
        container.add(buttonPanel, BorderLayout.CENTER);

        // 设置窗口
        setSize(300, 250);
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();

        if (command.matches("[0-9.]")) {
            // 数字或小数点
            if (operator == null) {
                display.setText(display.getText() + command);
            } else {
                if (num2 == 0 && command.equals(".")) {
                    display.setText(num1 + operator + "0" + command);
                } else {
                    display.setText(display.getText() + command);
                }
            }
        } else if (command.matches("[+\\-*/]")) {
            // 加减乘除
            if (operator != null) {
                num2 = Double.parseDouble(display.getText());
                result = calculate();
                display.setText(result + "");
                num1 = result;
            } else {
                num1 = Double.parseDouble(display.getText());
            }
            operator = command;
        } else if (command.equals("=")) {
            // 等于号
            num2 = Double.parseDouble(display.getText());
            result = calculate();
            display.setText(result + "");
            num1 = result;
            operator = null;
        } else if (command.equals("C")) {
            // 清除
            num1 = num2 = result = 0;
            operator = null;
            display.setText("");
        }
    }

    private double calculate() {
        switch (operator) {
            case "+":
                return num1 + num2;
            case "-":
                return num1 - num2;
            case "*":
                return num1 * num2;
            case "/":
                return num1 / num2;
            default:
                return 0;
        }
    }

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

运行后，可以看到一个简易的计算器界面，并且可以通过鼠标点击按键进行交互：