Java tutorial
import java.awt.BorderLayout; import javax.swing.BoxLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTextArea; public class Main { JFrame testFrame = new JFrame(); JTextArea firstTextArea, secondTextArea; JButton copyTextButton; public Main() { JPanel textPanel = new JPanel(); textPanel.setLayout(new BoxLayout(textPanel, BoxLayout.PAGE_AXIS)); firstTextArea = new JTextArea(10, 50); secondTextArea = new JTextArea(10, 50); textPanel.add(new JScrollPane(firstTextArea)); textPanel.add(new JScrollPane(secondTextArea)); testFrame.add(textPanel, BorderLayout.CENTER); copyTextButton = new JButton("Copy text"); copyTextButton.addActionListener(e -> copyText()); testFrame.add(copyTextButton, BorderLayout.SOUTH); } public JFrame getFrame() { return testFrame; } private void copyText() { secondTextArea.setText(firstTextArea.getText()); } public static void main(String[] args) { JFrame frame = new Main().getFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.pack(); frame.setVisible(true); } }