Difference between getClass().getClassLoader().getResource() and getClass.getResource()?

Question

What is the difference between getClass().getClassLoader().getResource() and getClass.getResource()?

When retrieving files from resources, which one should I use in what circumstances?

Answer 1

The second one calls the first one. The difference is described in the javadoc.

The first one takes paths that don't start with a /, and always starts at the root of the classpath.

The second one takes path that can start with a /. If it does, it starts at the root of the classpath. If not, it starts at the package of the class on which the method is called.

So getClass().getClassLoader().getResource("foo/bar.txt") is equivalent to getClass().getResource("/foo/bar.txt").

And, assuming getClass() returns a class that is in the package foo, getClass().getResource("bar.txt") is equivalent to getClass().getClassLoader().getResource("foo/bar.txt")

Answer 2

which one should I use in what circumstances?

Neither. You should call Thread.currentThread().getContextClassLoader().

This has the benefit of not needing to be changed depending on whether you're calling from a static or instance method.

And more important, it will properly handle classloader delegation inside a container. If you don't use it, you might find that an "application" resource isn't found because the class that's loading it was loaded by a classloader higher up the delegation hierarchy.