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nodeList.put(tokens[0], new SetLeaf(tokens[1], tokens[2])); //Nodelist<String, SetLeaf(String, String)>


Look at your code: you are calling "put" method, but also you are calling a constructor...

That code does not compile, but even fixing it.... your event listeners do nothing. The only method implemented is:

public void actionPerformed(ActionEvent ev) {
midgui.append(nounbox1.getText()...

Look Name should implements equals(Object o) method, overriding the Object.equals(...) one.
See
http://java.sun.com/javase/6/docs/api/java/util/Vector.html#indexOf(java.lang.Object) and...

Name should implements equals(Object o) method, overriding the Object.equals(...) one.
See
http://java.sun.com/javase/6/docs/api/java/util/Vector.html#indexOf(java.lang.Object) and...

Pay attention to dlorde post: 130 is "out" of cached integers, so a new Integer is created. So, i3 and i4 are different objects.

I pasted your JSP to my "Hello world" Struts (2.1.5) example and it worked.
The only diffecence I've found is in my web.xml file:


<?xml version="1.0" encoding="UTF-8"?>
<web-app id="person"...