怎样消除JTree在展开和合闭时的闪烁？（付代码）

[thresh1]

package test;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
import javax.swing.tree.*;

public class Applet1 extends Applet {


public void init(){
try{
DefaultMutableTreeNode root = new DefaultMutableTreeNode("root");
DefaultMutableTreeNode one = new DefaultMutableTreeNode("one");
DefaultMutableTreeNode two = new DefaultMutableTreeNode("two");
DefaultMutableTreeNode three = new DefaultMutableTreeNode("three");
one.add(new DefaultMutableTreeNode("1"));
one.add(new DefaultMutableTreeNode("2"));
one.add(new DefaultMutableTreeNode("3"));
one.add(new DefaultMutableTreeNode("4"));
one.add(new DefaultMutableTreeNode("5"));
one.add(new DefaultMutableTreeNode("6"));
one.add(new DefaultMutableTreeNode("7"));
root.add(one);
root.add(two);
root.add(three);
root.add(new DefaultMutableTreeNode("4"));
root.add(new DefaultMutableTreeNode("5"));
root.add(new DefaultMutableTreeNode("6"));
root.add(new DefaultMutableTreeNode("7"));
root.add(new DefaultMutableTreeNode("8"));
root.add(new DefaultMutableTreeNode("9"));
two.add(new DefaultMutableTreeNode("4"));
two.add(new DefaultMutableTreeNode("5"));
two.add(new DefaultMutableTreeNode("6"));
two.add(new DefaultMutableTreeNode("7"));
two.add(new DefaultMutableTreeNode("8"));
two.add(new DefaultMutableTreeNode("9"));


this.add(new JScrollPane().add(new JTree(new DefaultTreeModel(root))));

}
catch(Exception e) {
e.printStackTrace();
}

}

}

[肖尧19]

不会再有闪烁了：
/*
*<Applet code=Applet1 width=400 height=400>
*</Applet>
*/
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
import javax.swing.tree.*;

public class Applet1 extends Applet {


public void init(){
try{
DefaultMutableTreeNode root = new DefaultMutableTreeNode("root");
DefaultMutableTreeNode one = new DefaultMutableTreeNode("one");
DefaultMutableTreeNode two = new DefaultMutableTreeNode("two");
DefaultMutableTreeNode three = new DefaultMutableTreeNode("three");
one.add(new DefaultMutableTreeNode("1"));
one.add(new DefaultMutableTreeNode("2"));
one.add(new DefaultMutableTreeNode("3"));
one.add(new DefaultMutableTreeNode("4"));
one.add(new DefaultMutableTreeNode("5"));
one.add(new DefaultMutableTreeNode("6"));
one.add(new DefaultMutableTreeNode("7"));
root.add(one);
root.add(two);
root.add(three);
root.add(new DefaultMutableTreeNode("4"));
root.add(new DefaultMutableTreeNode("5"));
root.add(new DefaultMutableTreeNode("6"));
root.add(new DefaultMutableTreeNode("7"));
root.add(new DefaultMutableTreeNode("8"));
root.add(new DefaultMutableTreeNode("9"));
two.add(new DefaultMutableTreeNode("4"));
two.add(new DefaultMutableTreeNode("5"));
two.add(new DefaultMutableTreeNode("6"));
two.add(new DefaultMutableTreeNode("7"));
two.add(new DefaultMutableTreeNode("8"));
two.add(new DefaultMutableTreeNode("9"));
setLayout(new BorderLayout());
JPanel jpanel=new JPanel();
jpanel.add(new JScrollPane().add(new JTree(new DefaultTreeModel(root))));

add(jpanel,BorderLayout.CENTER);

//this.add();

}
catch(Exception e) {
e.printStackTrace();
}

}

}