Example analysis of Tree and scrollbar usage in swing

This article illustrates the use of Tree and scrollbars in swing. Share with you for your reference. The details are as follows:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
public class test extends JApplet{
  JTree tree;
  JTextField jtf;
  public void init(){
    Container contentPane = getContentPane();
    contentPane.setLayout(new BorderLayout());
    DefaultMutableTreeNode top = new DefaultMutableTreeNode("Options");
    DefaultMutableTreeNode a = new DefaultMutableTreeNode("A");
    top.add(a);
    DefaultMutableTreeNode a1 = new DefaultMutableTreeNode("A1");
    a.add(a1);
    DefaultMutableTreeNode a2 = new DefaultMutableTreeNode("A2");
    a.add(a2);
    DefaultMutableTreeNode b = new DefaultMutableTreeNode("B");
    top.add(b);
    DefaultMutableTreeNode b1 = new DefaultMutableTreeNode("B1");
    b.add(b1);
    DefaultMutableTreeNode b2 = new DefaultMutableTreeNode("B2");
    b.add(b2);
    tree = new JTree(top);
    int v = ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED;
    int h = ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED;
    JScrollPane jsp = new JScrollPane(tree,v,h);
    contentPane.add(jsp, BorderLayout.CENTER);
    jtf = new JTextField("", 20);
    contentPane.add(jtf, BorderLayout.SOUTH);
    tree.addMouseListener(new MouseAdapter(){
      public void mouseClicked(MouseEvent me){
        doMouseclicked(me);
      }
    });
  }
  void doMouseclicked(MouseEvent me){
    TreePath tp = tree.getPathForLocation(me.getX(), me.getY());
    if(tp !=null)
      jtf.setText(tp.toString());
    else
      jtf.setText("");
  }
}

I hope this article has been helpful to your Java programming.