ml?is-external=true" title="class or interface in java.net">URL</a>&nbsp;getPersistenceUnitRootUrl()</pre>
<div class="block">Returns the URL for the jar file or directory that is the
 root of the persistence unit. (If the persistence unit is
 rooted in the WEB-INF/classes directory, this will be the 
 URL of that directory.)
 The URL will either be a file: URL referring to a jar file 
 or referring to a directory that contains an exploded jar
 file, or some other URL from which an InputStream in jar
 forma