用Java写一个程序，实现如下图形用户界面，点击加法按钮，将两个文本框数值进行加法运算显示在最后一个标签中

很高兴为您解答。以下是使用Java Swing编写的程序代码，实现您所描述的GUI。

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

public class CalculatorGUI extends JFrame implements ActionListener {
    private JLabel label1, label2, resultLabel;
    private JTextField textField1, textField2;
    private JButton addButton;

    public CalculatorGUI() {
        setTitle("Calculator");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(400, 150);
        setResizable(false);

        // create labels
        label1 = new JLabel("Number 1:");
        label2 = new JLabel("Number 2:");
        resultLabel = new JLabel("Result:");

        // create text fields
        textField1 = new JTextField(10);
        textField2 = new JTextField(10);

        // create add button
        addButton = new JButton("Add");
        addButton.addActionListener(this);

        // create panels
        JPanel panel1 = new JPanel(new GridLayout(3, 2));
        JPanel panel2 = new JPanel(new FlowLayout(FlowLayout.CENTER));

        // add components to panel1
        panel1.add(label1);
        panel1.add(textField1);
        panel1.add(label2);
        panel1.add(textField2);
        panel1.add(resultLabel);

        // add components to panel2
        panel2.add(addButton);

        // add panels to frame
        add(panel1, BorderLayout.NORTH);
        add(panel2, BorderLayout.CENTER);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == addButton) {
            try {
                double num1 = Double.parseDouble(textField1.getText());
                double num2 = Double.parseDouble(textField2.getText());
                double result = num1 + num2;
                resultLabel.setText("Result: " + result);
            } catch (NumberFormatException ex) {
                resultLabel.setText("Result: Invalid input");
            }
        }
    }

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

运行该程序后，将会显示一个带有两个文本框和一个加法按钮的GUI界面。用户可以在文本框中输入数字，然后单击“Add”按钮执行加法操作，并将结果显示在标签中。