用Java语言帮我写一个可视化的计算器

好的，以下是一个简单的基于Java Swing的可视化计算器的代码：

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

public class Calculator extends JFrame implements ActionListener {

    private static final long serialVersionUID = 1L;
    private JTextField textField;
    private JPanel buttonPanel;

    private double num1, num2;
    private String operator;

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

        textField = new JTextField();
        add(textField, BorderLayout.NORTH);

        buttonPanel = new JPanel(new GridLayout(4, 4));
        addButton("7");
        addButton("8");
        addButton("9");
        addButton("/");
        addButton("4");
        addButton("5");
        addButton("6");
        addButton("*");
        addButton("1");
        addButton("2");
        addButton("3");
        addButton("-");
        addButton("0");
        addButton(".");
        addButton("=");
        addButton("+");

        add(buttonPanel, BorderLayout.CENTER);
    }

    private void addButton(String label) {
        JButton button = new JButton(label);
        button.addActionListener(this);
        buttonPanel.add(button);
    }

    private void calculate() {
        if (operator.equals("+")) {
            num2 = Double.parseDouble(textField.getText());
            textField.setText(Double.toString(num1 + num2));
        } else if (operator.equals("-")) {
            num2 = Double.parseDouble(textField.getText());
            textField.setText(Double.toString(num1 - num2));
        } else if (operator.equals("*")) {
            num2 = Double.parseDouble(textField.getText());
            textField.setText(Double.toString(num1 * num2));
        } else if (operator.equals("/")) {
            num2 = Double.parseDouble(textField.getText());
            if (num2 == 0) {
                textField.setText("Error");
            } else {
                textField.setText(Double.toString(num1 / num2));
            }
        }
    }

    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();
        if (command.equals("+") || command.equals("-") || command.equals("*") || command.equals("/")) {
            num1 = Double.parseDouble(textField.getText());
            operator = command;
            textField.setText("");
        } else if (command.equals("=")) {
            calculate();
            operator = "";
        } else {
            textField.setText(textField.getText() + command);
        }
    }

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

运行后，你将得到一个简单的可视化计算器。希望能够帮到你！