import java.awt.Container;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.text.Document;
public class MainClass {
public static void main(String args[]) {
JFrame frame = new JFrame("Sharing Sample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container content = frame.getContentPane();
JTextArea textarea1 = new JTextArea();
Document document = textarea1.getDocument();
JTextArea textarea2 = new JTextArea(document);
JTextArea textarea3 = new JTextArea(document);
content.setLayout(new BoxLayout(content, BoxLayout.Y_AXIS));
content.add(new JScrollPane(textarea1));
content.add(new JScrollPane(textarea2));
content.add(new JScrollPane(textarea3));
frame.setSize(300, 400);
frame.setVisible(true);
}
}