Scrollbar is not appearing in a JPanel

Question

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.*;
import java.awt.Dimension;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JScrollPane;
import javax.swing.border.LineBorder;

class Test
{
public Test()
{
    JFrame f = new JFrame();
    f.setSize(800,800);
    f.setLayout(new FlowLayout());

    JPanel s = new JPanel();
    s.setLayout(new BoxLayout(s,BoxLayout.PAGE_AXIS));

    JLabel m = new JLabel("D");
    JLabel m1 = new JLabel("D1");
    JLabel m2 = new JLabel("D1");
    JLabel m3 = new JLabel("D1");
    JLabel m4 = new JLabel("D1");
    JLabel m5 = new JLabel("D1");
    JLabel m6 = new JLabel("D1");
    JLabel m7 = new JLabel("D1");
    JLabel m8 = new JLabel("D1");

    s.add(m);
    s.add(m1);
    s.add(m2);
    s.add(m3);
    s.add(m4);
    s.add(m5);
    s.add(m6);
    s.add(m7);
    s.add(m8);

    JScrollPane scroll = new JScrollPane(s);

    //scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
    scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
    scroll.setViewportBorder(new LineBorder(Color.RED));

    f.add(scroll);

    f.setVisible(true);
}

public static void main(String args[])
{
    Test t = new Test();
}
}

Everything is ok,but the Scroll is not showing (JScollPane is appearing) .. and is there a better way to do this ? I mean - the proper way to show a JScrollPane in a panel ...... ?

It's showing like this

Answer 1

Scrollbars appear when the preferred size of the component added to the scollpane is greater than the size of the scrollpane.

JScrollPane scroll = new JScrollPane(s);
scroll.setPreferredSize(new Dimension(100, 50));

Scroll pane will expand its height as you add elements into it, unless you set the preferred size.