"alesj" wrote : OK, NoCopy speeds things up. | But doing some more profiling, looks like our VirtualFileURLConnection is the cause of it all. :-) | | Creating new VirtualFile for every new connection. Meaning it builds the whole jar structure to get to a single resource. | | Scott, does your url-connection branch deal with this? | Or where/how to plug-in this sore of cache: url --> virtual file? The urlconn branch does not introduce extra caching, it just avoid relying on the URL details. What is calling URL.openStream in this trace? A VirtualFileURLConnection.getInputStream cache might be one cache to introduce. The AbstractURLHandler.openStream would be the other place. The main problem will be making sure these streams are closed to avoid leaks/locks. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4116137#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...