"alesj" wrote : | While you can easily rename file, you probably cannot fix it. | But how many .jar files did you see that were not actually jars, opposed to broken zips. ;-) You mean besides directories being unpacked jars? ;-) I guess we could add an extra check that tries to open the raw stream and see whether it contains the magic PK at the start: http://en.wikipedia.org/wiki/Magic_number_(programming) If it does then throw an IOException about the broken archive. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4135938#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...