Where is it documented that getResource() will find data in the jar?

Question

Hello, if I package data in the .jar that is different than .class, then it was posted here a while ago by atomguy, that the following code will work
URL url = getClass().getResource("/Your/Filepath/inthe/Jar");
My question is, where does it say so? The rationale for my question is, this may work now, but if it is an undocumented feature, then one day when my customer downloads some future Java version, it might not work anymore. So I want to know that this is a documented feature before I use it, as such features are far less likely to be changed by Sun (backwards compatibility).
I read the documentation on getResource(), ultimately this seems to be delegated to ClassLoader instance getResource(), I read that doc too, and I don't see where it implies that it will produce a URL that I can then use to access the data file in the jar, for sure.
Please point me where in the docs it follows from.
Thank you,
Mark

Answer 1

I'm no expert, but I would say it is a documented feature that a classloader searches for and loads classes that the JVM needs - it's in the JLS and Sun JVM specs. It's documented that getResource() calls the object's classloader getSystemResource() and returns the URL for the named resource.
If you put resources in places where the classload finds classes, then those resources will be found by the same classloader. Any jar (or any directory) that contains classes that have been loaded MUST be in the search path of the classloader. (I am assuming the bootstrap classloader - if a custom classloader is used, then it might not behave the same.)
Edited by: atmguy on Mar 1, 2009 9:38 AM