import java.awt.Dimension;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
public class Main {
public static void main(String args[]) {
JTable table = new JTable(22, 5);
table.setPreferredScrollableViewportSize(new Dimension(400, 300));
final JScrollPane scrollPane = new JScrollPane(table);
JButton cornerButton = new JButton("#");
scrollPane.setCorner(JScrollPane.UPPER_TRAILING_CORNER, cornerButton);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
JFrame frame = new JFrame();
frame.add(scrollPane);
frame.pack();
frame.setVisible(true);
}
}