"sacha.labourey(a)jboss.com" wrote : What about using the same class from the Apache Java implementation? I doubt they have the same bug. Because it uses native code. But more importantly, even if we use org.apache.xxx.JarFile or org.jboss.xxx.JarFile that doesn't mean everybody will. e.g. Hibernate opens jar files to scan for annotations. Of course if this causes locking problems then we can use Ales's new unpack option to give them a temporary copy. But ideally we want to be minimizing the number of cases where this is required. i.e. by finding other workarounds that don't require the unpacking. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4145813#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...