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

以下是一个简单的 Java 计算器实现，使用 Swing 组件库构建 UI 界面，实现加减乘除四则运算。

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

public class Calculator extends JFrame implements ActionListener {

    private JTextField textField;
    private JButton btn0, btn1, btn2, btn3, btn4, btn5, btn6, btn7, btn8, btn9;
    private JButton btnPlus, btnMinus, btnMultiply, btnDivide, btnEqual, btnClear;

    private double num1 = 0, num2 = 0, result = 0;
    private String operator = "";

    public Calculator() {
        setTitle("Calculator");
        setSize(300, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);

        // Setup UI
        JPanel panel = new JPanel(new GridLayout(4, 4, 10, 10));
        panel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
        textField = new JTextField();
        textField.setEditable(false);
        panel.add(textField);

        btn0 = new JButton("0");
        btn1 = new JButton("1");
        btn2 = new JButton("2");
        btn3 = new JButton("3");
        btn4 = new JButton("4");
        btn5 = new JButton("5");
        btn6 = new JButton("6");
        btn7 = new JButton("7");
        btn8 = new JButton("8");
        btn9 = new JButton("9");
        btnPlus = new JButton("+");
        btnMinus = new JButton("-");
        btnMultiply = new JButton("*");
        btnDivide = new JButton("/");
        btnEqual = new JButton("=");
        btnClear = new JButton("C");

        panel.add(btn7);
        panel.add(btn8);
        panel.add(btn9);
        panel.add(btnPlus);
        panel.add(btn4);
        panel.add(btn5);
        panel.add(btn6);
        panel.add(btnMinus);
        panel.add(btn1);
        panel.add(btn2);
        panel.add(btn3);
        panel.add(btnMultiply);
        panel.add(btn0);
        panel.add(btnClear);
        panel.add(btnEqual);
        panel.add(btnDivide);

        add(panel);

        // Add event listeners
        btn0.addActionListener(this);
        btn1.addActionListener(this);
        btn2.addActionListener(this);
        btn3.addActionListener(this);
        btn4.addActionListener(this);
        btn5.addActionListener(this);
        btn6.addActionListener(this);
        btn7.addActionListener(this);
        btn8.addActionListener(this);
        btn9.addActionListener(this);
        btnPlus.addActionListener(this);
        btnMinus.addActionListener(this);
        btnMultiply.addActionListener(this);
        btnDivide.addActionListener(this);
        btnEqual.addActionListener(this);
        btnClear.addActionListener(this);
    }

    // Handle button click events
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == btn0) {
            textField.setText(textField.getText() + "0");
        } else if (e.getSource() == btn1) {
            textField.setText(textField.getText() + "1");
        } else if (e.getSource() == btn2) {
            textField.setText(textField.getText() + "2");
        } else if (e.getSource() == btn3) {
            textField.setText(textField.getText() + "3");
        } else if (e.getSource() == btn4) {
            textField.setText(textField.getText() + "4");
        } else if (e.getSource() == btn5) {
            textField.setText(textField.getText() + "5");
        } else if (e.getSource() == btn6) {
            textField.setText(textField.getText() + "6");
        } else if (e.getSource() == btn7) {
            textField.setText(textField.getText() + "7");
        } else if (e.getSource() == btn8) {
            textField.setText(textField.getText() + "8");
        } else if (e.getSource() == btn9) {
            textField.setText(textField.getText() + "9");
        } else if (e.getSource() == btnPlus) {
            num1 = Double.parseDouble(textField.getText());
            operator = "+";
            textField.setText("");
        } else if (e.getSource() == btnMinus) {
            num1 = Double.parseDouble(textField.getText());
            operator = "-";
            textField.setText("");
        } else if (e.getSource() == btnMultiply) {
            num1 = Double.parseDouble(textField.getText());
            operator = "*";
            textField.setText("");
        } else if (e.getSource() == btnDivide) {
            num1 = Double.parseDouble(textField.getText());
            operator = "/";
            textField.setText("");
        } else if (e.getSource() == btnEqual) {
            num2 = Double.parseDouble(textField.getText());
            switch (operator) {
                case "+":
                    result = num1 + num2;
                    break;
                case "-":
                    result = num1 - num2;
                    break;
                case "*":
                    result = num1 * num2;
                    break;
                case "/":
                    result = num1 / num2;
                    break;
            }
            textField.setText(Double.toString(result));
        } else if (e.getSource() == btnClear) {
            textField.setText("");
        }
    }

    public static void main(String[] args) {
        Calculator calc = new Calculator();
        calc.setVisible(true);
    }
}

该计算器实现了一个 `JTextField` 用于显示输入和计算结果，以及多个 `JButton` 用于表示数字、运算符和清除按钮。其中，数字按钮和运算符按钮都绑定了 `ActionListener` 监听器，通过判断事件源的不同来实现不同的操作。计算器的核心计算逻辑在 `actionPerformed` 方法中实现，根据不同的运算符执行不同的计算操作，并将结果显示在文本框中。

注意，在计算过程中需要将字符串转换成浮点数进行计算，最后再将结果转换回字符串显示在文本框中。

完整代码：https://github.com/JackieLin0328/calculator-java