Swing tree java code

[bibingigin]

My java code is as follows

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
public class jtrexp extends JFrame
{
JTree jt;
DefaultMutableTreeNode top,ff,df,ff1,ff2,ff3,df1,df2,df3;
JTextField f1;
	public jtrexp()
	{
		
		setLayout(new BorderLayout());		
		top=new DefaultMutableTreeNode("Fruits");
		ff=new DefaultMutableTreeNode("Fresh Fruits");
		df=new DefaultMutableTreeNode("Dry Fruits");
		ff1=new DefaultMutableTreeNode("Apple");
		ff2=new DefaultMutableTreeNode("Orange");
		ff3=new DefaultMutableTreeNode("Grapes");
		df1=new DefaultMutableTreeNode("Strawberry");
		df2=new DefaultMutableTreeNode("Dates");
		df3=new DefaultMutableTreeNode("Beaches");
		ff.add(ff1);
		ff.add(ff2);
		ff.add(ff3);
		df.add(df1);
		df.add(df2);
		df.add(df3);
		top.add(ff);
		top.add(df);
		jt=new JTree(top);
		jt.setFont(new Font("Times New Roman",Font.BOLD,20));
		jt.setRowHeight(40);
		add(jt);
		f1=new JTextField(20);
		add(f1,"south");
		jt.addMouseListener(new MouseAdapter()
		{
			public void mouseClicked(MouseEvent me)
			{
			TreePath tp=jt.getPathForLocation(me.getX(),me.getY());
			if(tp!=null)
				f1.setText(tp.toString());
			else
				f1.setText("");
		
			}
		});
		

	}
	public static void main(String arg[])
	{
		jtrexp jj=new jtrexp();
		jj.setSize(400,400);
		jj.setVisible(true);
	
	}
}

When i run the code it shows,

Exception in thread "main" java.lang.ErrorDo not use jtrexp.setLayout()  use jtrexp.setLayout().getContentPane().setLayout() instead
         at javax.swing.JFrame.createRootPaneException(JFrame.java.406)
         at javax.swing.JFrame.setLayout(JFrame.java.472)
         at jtrexp.<init>(jtrexp.java.13)
         at jtrexp.main(jtrexp.java.54)

[DarrylBurke]

Use the code tags to post code. Since you're new here, I've added them for you this time round.

What's your Java version? and how exactly are you running the code?

db

[DarrylBurke]

And if you're running GNU Java aka GCJ, get rid of all traces of it from your computer and install a Sun/Oracle JDK.

db