title: jar file gets corrupted while building with maven
body: <p>while building a war file i am copying a set of jars from a location to a folder inside the war. While the files do get copied , however i think they get corrupted because the same class files of the jar when taken outside the war opens with a debugger while it does not open after taking from war file . </p>
  
  <p>This is a part of my war pom.xml where i  copy the jars </p>
  
  <pre><code>&lt;execution&gt; 
      &lt;id&gt;copy-jars&lt;/id&gt; 
      &lt;phase&gt;process-resources&lt;/phase&gt; 
      &lt;goals&gt; 
          &lt;goal&gt;copy-resources&lt;/goal&gt; 
      &lt;/goals&gt; 
      &lt;configuration&gt; 
          &lt;outputDirectory&gt;${basedir}/target/${project.artifactId}-${buildNumber}/somefolder&lt;/outputDirectory&gt; 
           &lt;resources&gt; 
              &lt;resource&gt; 
                  &lt;directory&gt;SomeSourceDirectory&lt;/directory&gt; 
                  &lt;filtering&gt;true&lt;/filtering&gt; 
                  &lt;includes&gt; 
                      &lt;include&gt;**/**&lt;/include&gt; 
                  &lt;/includes&gt;
              &lt;/resource&gt;
          &lt;/resources&gt; 
      &lt;/configuration&gt; 
  &lt;/execution&gt;
  </code></pre>
  
  <p><em>SomeSourceDirectory</em> has some jars and some other files
  The result is:
  myWar/somefolder/a.jar   but when i open the classes inside this jar in a debugger..i get error in WinZip that </p>
  
  <pre><code>Invalid compressed data to extract.
  Severe Error:  Compressed data is invalid
  </code></pre>
  
  <p>However the same class file can be viewed when i view it in original folder i.e outside the war.
  So is there a mistake while copying the jars?
  Thanks.</p>