Java BoxLayout PAGE_AXIS

public static final int PAGE_AXIS

import java.awt.BorderLayout;
// w w w .j  a  v  a 2s. c  om
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main {

  public static void main(String[] a) {
    JFrame frame = new JFrame("Alignment Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    String labels[] = { "--", "----", "--------", "------------" };

    JPanel container = new JPanel();
    BoxLayout layout = new BoxLayout(container, BoxLayout.PAGE_AXIS);
    container.setLayout(layout);

    for (int i = 0; i < labels.length; i++) {
      JButton button = new JButton(labels[i]);
      container.add(button);
    }

    frame.add(container, BorderLayout.CENTER);

    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}