The problem with the current JBVFS-59 FileVFSUnitTestCase.testWarLinkUpdate failures is that the test is rapidly modifying the underlying test-link.war.vfslink.properties file, but the resolution of the URLConnection.getLastModified() is >1000 microseconds on some systems. We need a better implementation of the VirtualFileHandler.hasBeenModified for each URL type. We had dropped our override of the file: URL handler because what we were overriding had been implemented in later jdk versions. I assume this resolution limitation is coming from the java.io.File implementation, so I don't know what we can do about it at this point.