Java编写一个应用程序，有一个FlowLayout布局的窗口，实现加、减、乘、除、乘方、开方。

下面是 Java 代码实现的示例：

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

public class Calculator extends JFrame {
    private JTextField resultField;
    private JButton addButton, subtractButton, multiplyButton, divideButton, powerButton, sqrtButton;

    public Calculator() {
        setTitle("计算器");
        setSize(250, 200);
        setDefaultCloseOperation(EXIT_ON_CLOSE);

        resultField = new JTextField(20);
        resultField.setEditable(false);
        add(resultField, BorderLayout.NORTH);

        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new FlowLayout());

        addButton = new JButton("+");
        subtractButton = new JButton("-");
        multiplyButton = new JButton("*");
        divideButton = new JButton("/");
        powerButton = new JButton("^");
        sqrtButton = new JButton("√");

        addButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 加法实现
            }
        });

        subtractButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 减法实现
            }
        });

        multiplyButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 乘法实现
            }
        });

        divideButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 除法实现
            }
        });

        powerButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 乘方实现
            }
        });

        sqrtButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                // 开方实现
            }
        });

        buttonPanel.add(addButton);
        buttonPanel.add(subtractButton);
        buttonPanel.add(multiplyButton);
        buttonPanel.add(divideButton);
        buttonPanel.add(powerButton);
        buttonPanel.add(sqrtButton);
        add(buttonPanel, BorderLayout.CENTER);
    }

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

这是一个利用 FlowLayout 布局的简单计算器，可以实现加、减、乘、除、乘方和开方等操作。代码中给出了每个操作的