title: Adding manifest properties to existing jar files with ant
body: <p>Since the latest java release (7u45), I'm getting tons of errors on third part jar libraries that my webstart application uses, due to newly required manifest attributes being missing:</p>
  
  <pre><code>Missing Application-Name: manifest attribute for: http://site/lib/jh.jar
  Missing Permissions manifest attribute for: http://site/lib/jh.jar
  Missing Codebase manifest attribute for: http://lib/jh.jar
  </code></pre>
  
  <p>So, I need to run a batch ant task to update the manifest files in each of the 30 or so required libraries before I can use them for distribution.</p>
  
  <p>How can I do this in ant? (preferably without ant-contrib)</p>
  
  <p>PS: I've already fixed all the other 7u45 update crap (code signing, JNLP attribs, etc).</p>