Why is java.util.TreeSet not seen in applet under IE5.5?

Hi,
I developed an applet to read a serialized file and tested on JBuilder; it worked fine. However, when I tested on IE5.5, an error message displayed: "ClassNotFoundException: class java.util.TreeSet is not found".
I used TreeSet to store data.
Anyone has any ideas of how to fix this?
Thanks,
Tom

This is what I did:
import java.awt.*;
import java.applet.*;
public class BookmarkApplet extends Applet {
   public void init() {
          //String fileName = this.getParameter("gx26187") + ".ser";
          String fileName = "gx26187" + ".ser";
          Bookmark bookmark = new Bookmark(fileName);
          LinkHolder linkHolder = new LinkHolder();
          for(int i = 0; i < 10; i++) {
               linkHolder.add(new Link("url"+i, "link"+i));
          if(bookmark.save(linkHolder)) {
               linkHolder = bookmark.retrieve();
               Link[] retreivedLinks = linkHolder.getLinks();
               if(retreivedLinks != null && retreivedLinks.length > 0) {
                    Link [] trimmedLinks = new Link[linkHolder.getSize()];
                    System.arraycopy(retreivedLinks, 0, trimmedLinks, 0, trimmedLinks.length);
                    for(int i = 0; i < trimmedLinks.length; i++) {
                         add(new Button(trimmedLinks.getDescription()));
LinkHolder is a wrapper class in which I used Link[] to store objects.
Link is a class that stores 2 strings: links and description.
I tested this on JBuilder ==> worked fine.
I tested on IE ==> applet is running but nothing shown up.
Thanks if any ideas.
Tom
Yeah I do.
If its anything like my problems you will find Treeset
is from JDK 1.2+
IE's virtual machine runs using the == of jdk 1.1
This means with out using plugins you HAVE to use
features of 1.1 Im sure you could use another
datastructure instead.
Hope this helps.
U can extract the Treeset files from rt.jar but im
still unable to determine if thats legal

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LinkHolder is a wrapper class in which I used Link[] to store objects.
Link is a class that stores 2 strings: links and description.
I tested this on JBuilder ==> worked fine.
I tested on IE ==> applet is running but nothing shown up.
Thanks if any ideas.
Tom
Yeah I do.
If its anything like my problems you will find Treeset
is from JDK 1.2+
IE's virtual machine runs using the == of jdk 1.1
This means with out using plugins you HAVE to use
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Hope this helps.
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