java.net.URL cache when reading from files
file, io, java
Solution
Because of the `jar` protocol used in your URL, the connection is an instance of sun.net.www.protocol.jar.JarURLConnection which takes benefit from a cache implemented in sun.net.www.protocol.jar.JarFileFactory
Source code confirms a `setUseCache(false)` on `URLConnection` implementation will prevent the use of that cache.
My hypothesis about the Linux/Windows behavior difference: the close event notification from URLJarFileCloseController interface is triggered faster on Windows because it does not appreciate to keep file handles opened for a too long period...
Problem
It seems like java is holding some kind of a cache to URL (& files). e.g. I have a file "resourcs.txt" in a jar file in my classpath. The content of this file is: "Version 1" ``` new java.io.BufferedReader (new java.io.InputStreamReader( new URL("jar", "", "file:test.jar!/resourcs.txt").openConnection().getInputStream())).readLine() ``` returns "Version 1" (as expected) I change the file content to be "Version 2" and call again to this code. And I still get "Version 1" How can I clear this "cache". Notice: I found out it only happens on Linux.