实验目的：练习swing布局和事件处理 。实验要求：通过java制作计算器的界面和简单功能

好的，这个实验要求你使用Java Swing布局和事件处理来制作一个简单的计算器。下面是一个简单的示例代码，演示了如何创建计算器的界面和实现加法操作：

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

public class Calculator extends JFrame implements ActionListener {

    private JTextField textField;
    private JButton button1, button2, button3, button4, button5, button6, button7, button8, button9, button0;
    private JButton buttonAdd, buttonMinus, buttonMultiply, buttonDivide, buttonEqual, buttonClear;

    private double firstNumber = 0;
    private String operator = "";
    
    public Calculator() {

        setTitle("Calculator");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 300);
        setResizable(false);
        setLocationRelativeTo(null);

        textField = new JTextField();
        textField.setEditable(false);

        button1 = new JButton("1");
        button2 = new JButton("2");
        button3 = new JButton("3");
        button4 = new JButton("4");
        button5 = new JButton("5");
        button6 = new JButton("6");
        button7 = new JButton("7");
        button8 = new JButton("8");
        button9 = new JButton("9");
        button0 = new JButton("0");

        buttonAdd = new JButton("+");
        buttonMinus = new JButton("-");
        buttonMultiply = new JButton("*");
        buttonDivide = new JButton("/");
        buttonEqual = new JButton("=");
        buttonClear = new JButton("C");

        button1.addActionListener(this);
        button2.addActionListener(this);
        button3.addActionListener(this);
        button4.addActionListener(this);
        button5.addActionListener(this);
        button6.addActionListener(this);
        button7.addActionListener(this);
        button8.addActionListener(this);
        button9.addActionListener(this);
        button0.addActionListener(this);

        buttonAdd.addActionListener(this);
        buttonMinus.addActionListener(this);
        buttonMultiply.addActionListener(this);
        buttonDivide.addActionListener(this);
        buttonEqual.addActionListener(this);
        buttonClear.addActionListener(this);

        JPanel panel1 = new JPanel(new GridLayout(4, 3));
        panel1.add(button1);
        panel1.add(button2);
        panel1.add(button3);
        panel1.add(button4);
        panel1.add(button5);
        panel1.add(button6);
        panel1.add(button7);
        panel1.add(button8);
        panel1.add(button9);
        panel1.add(button0);
        panel1.add(buttonClear);
        panel1.add(buttonEqual);

        JPanel panel2 = new JPanel(new GridLayout(4, 1));
        panel2.add(buttonAdd);
        panel2.add(buttonMinus);
        panel2.add(buttonMultiply);
        panel2.add(buttonDivide);

        JPanel panel3 = new JPanel(new GridLayout(2, 1));
        panel3.add(textField);
        panel3.add(panel2);

        setLayout(new BorderLayout());
        add(panel1, BorderLayout.CENTER);
        add(panel3, BorderLayout.EAST);

        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {

        if (e.getSource() == buttonClear) {
            textField.setText("");
            firstNumber = 0;
            operator = "";
        } else if (e.getSource() == buttonAdd) {
            firstNumber = Double.parseDouble(textField.getText());
            textField.setText("");
            operator = "+";
        } else if (e.getSource() == buttonMinus) {
            firstNumber = Double.parseDouble(textField.getText());
            textField.setText("");
            operator = "-";
        } else if (e.getSource() == buttonMultiply) {
            firstNumber = Double.parseDouble(textField.getText());
            textField.setText("");
            operator = "*";
        } else if (e.getSource() == buttonDivide) {
            firstNumber = Double.parseDouble(textField.getText());
            textField.setText("");
            operator = "/";
        } else if (e.getSource() == buttonEqual) {
            double secondNumber = Double.parseDouble(textField.getText());
            double result = 0;
            if (operator.equals("+")) {
                result = firstNumber + secondNumber;
            } else if (operator.equals("-")) {
                result = firstNumber - secondNumber;
            } else if (operator.equals("*")) {
                result = firstNumber * secondNumber;
            } else if (operator.equals("/")) {
                result = firstNumber / secondNumber;
            }
            textField.setText(String.valueOf(result));
            firstNumber = 0;
            operator = "";
        } else {
            textField.setText(textField.getText() + e.getActionCommand());
        }
    }

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

这个代码创建了一个名为Calculator的类，继承了JFrame类，并实现了ActionListener接口。它创建了一个文本框和一些按钮，并使用GridLayout和BorderLayout来布局它们。它还实现了ActionListener接口的actionPerformed方法，以响应按钮的单击事件。通过这个程序，你可以练习使用Swing布局和事件处理来制作计算器这样的简单应用程序。