title: What causes "duplicate entry" warnings when JAR'ing with Eclipse?
body: <p>I am <code>jar</code>ing my Java Swing application which also uses <code>joda.time</code>, <code>apache.commons</code> and a few other external <code>jar</code>s.</p>
  
  <p>The output <code>jar</code> runs, however, Eclipse did report some warnings while producing the <code>jar</code> via Export > Java > Runnable Jar.  I am choosing the "repackage" option for dealing with the external <code>jar</code>s.  Here's the top of the listing of about 146 lines of warnings.</p>
  
  <pre><code>  JAR export finished with warnings. See details for additional information.
  
    Details:
    duplicate entry: allclasses-frame.html
    duplicate entry: allclasses-frame.html
    duplicate entry: allclasses-noframe.html
    duplicate entry: allclasses-noframe.html
    duplicate entry: constant-values.html
    duplicate entry: constant-values.html
    duplicate entry: deprecated-list.html
    duplicate entry: deprecated-list.html
    duplicate entry: help-doc.html
    duplicate entry: help-doc.html
    duplicate entry: index-all.html
    duplicate entry: index-all.html
    duplicate entry: index.html
    duplicate entry: index.html
    duplicate entry: overview-frame.html
    duplicate entry: overview-frame.html
    duplicate entry: overview-summary.html
    duplicate entry: overview-summary.html
    duplicate entry: overview-tree.html
    duplicate entry: overview-tree.html
    duplicate entry: package-list
    duplicate entry: package-list
    duplicate entry: resources/inherit.gif
    duplicate entry: resources/inherit.gif
  </code></pre>
  
  <p>As this is a Swing application for the desktop, warnings about <code>html</code> and <code>css</code> (not shown) are quite unexpected.  Advice?</p>