title: Is java.util.Observable used anywhere?
body: <p>Was chatting to a colleague about the design of Javas libraries. I mentioned I'd always found it funny that the AWT/Swing classes called that essentially provide an Observable interface on a UI widget were actually called "listeners".</p>
  
  <p>Whereupon he floored me by pointing out that there would have been a name clash with <a href="http://java.sun.com/j2se/1.4.2/docs/api/java/util/Observer.html" rel="noreferrer">java.util.Observer</a> and <a href="http://java.sun.com/j2se/1.4.2/docs/api/java/util/Observable.html" rel="noreferrer">java.util.Observable</a>, which have been around since JDK 1.0. I'd never heard of them before.</p>
  
  <p>There are no usages listed in the JavaDocs and google/<a href="http://www.google.com/codesearch?q=extends+Observable+lang%3AJava&amp;hl=en&amp;btnG=Search+Code" rel="noreferrer">googlecode</a> don't come up with much, so does anyone know if they are used somewhere in the JDK? They don't seem to have received any Generic love, so presumably they're not "popular". Has anyone found them useful?</p>