我想为GUI编写测试用例。我想知道如何模拟JButton的单击，或者如何提取JTable的元素。

为此，我构建了一个简单的GUI，如果单击按钮并且JTextfield为空，则将计数增加1，但是如果提供了数字，则计数将被JTextfield中的整数代替。当然，我想使用Regex来确保输入到JTextfield中的文本实际上是整数，但是让我们假设用户不会四处乱逛并输入非整数。另外，当JTable添加新行时，JLabel将更新当前计数。

这是代码：

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.GroupLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;


public class sampleGUI extends JFrame implements ActionListener {
    private Integer previous_count;
    private Integer current_count;
    private JButton Button;
    private JTable table;
    private JTextField text;
    private DefaultTableModel model;
    private JScrollPane scroll;
    private JLabel label;

    public sampleGUI() {
        previous_count = null;
        current_count = 0;
        JFrame frame = new JFrame("Sample");
        JPanel panel = new JPanel();

        GroupLayout layout = new GroupLayout(panel);
        panel.setLayout(layout);

        label = new JLabel("Current Count: " + Integer.toString(current_count));
        text = new JTextField(15);
        Button = new JButton("Change the Count!");
        model = new DefaultTableModel();
        model.addColumn("Previous Count");
        model.addColumn("Current Count");
        table = new JTable(model);
        scroll = new JScrollPane(table);

        layout.setHorizontalGroup(layout
                .createParallelGroup(GroupLayout.Alignment.LEADING)
                .addGroup(
                        layout.createSequentialGroup().addComponent(label)
                                .addComponent(text).addComponent(Button))

                .addComponent(scroll));

        layout.setVerticalGroup(layout
                .createSequentialGroup()
                .addGroup(
                        layout.createParallelGroup(
                                GroupLayout.Alignment.BASELINE)
                                .addComponent(label).addComponent(text)
                                .addComponent(Button)).addComponent(scroll));
        Button.addActionListener(this);

        frame.add(panel);
        frame.pack();
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == Button) {
            if (text.getText().equals("")) {
                previous_count = current_count;
                current_count++;
                label.setText("Current Count: "
                        + Integer.toString(current_count));
                model.addRow(new Object[] { current_count, previous_count });
            } else {
                previous_count = current_count;
                current_count = Integer.parseInt(text.getText());
                label.setText("Current Count: "
                        + Integer.toString(current_count));
                text.setText("");
                model.addRow(new Object[] { current_count, previous_count });
            }
            table.changeSelection(table.getRowCount() - 1, 0, false,
                    false);
        }
    }

    public static void main(final String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                sampleGUI gui = new sampleGUI();
            }
        });
    }
}

假设我要模拟打开GUI，然后单击一次按钮而不输入任何文本，然后输入1234并单击按钮，然后单击按钮而不输入任何文本，JTable应该具有3列：{{1,0
}，{1234、1}，{1235、1234}}。我该如何编写测试？谢谢！