Java で独自の Jar のマニフェストにアクセスするにはどうすればよいですか?

Enumeration<URL> resources = getClass().getClassLoader()
   .getResources("META-INF/MANIFEST.MF");
while (resources.hasMoreElements()) {
     try {
       Manifest manifest = new Manifest(resources.nextElement().openStream());
       // check that this is your manifest and do what you need or get the next one
       ...
     } catch (IOException E) {
       // handle
     }
}

URLClassLoader cl = (URLClassLoader) getClass().getClassLoader();
try {
   URL url = cl.findResource("META-INF/MANIFEST.MF");
   Manifest manifest = new Manifest(url.openStream());
   // do stuff with it
   ...
} catch (IOException E) {
   // handle
}