Struts 2.3.16 - DefaultActionValidatorManager.loadFile() throws NullPointerException while loading Object-validation.xml

Question

We are upgrading struts from 2.0.11 to 2.3.16.

In our code while trying to get DefaultActionValidatorManager.getValidators(getClass(), null), it throws a NullPointerException from DefaultActionValidatorManager.loadFile() while it tries to load java/lang/Object-validation.xml.

Searching on internet I found a similar issue was reported as WW-3850. It says the issue is fixed in xwork 2.3.7. I took a look at xwork 2.3.7 source and it has the mentioned changed (additional null check fileUrl != null). This check is present till xwork 2.3.14.3 and is removed from 2.3.15 onward.

Any idea if this is a regression and needs to fixed in 2.3.15 onwards? Or there is another way of using DefaultActionValidatorManager.getValidators() starting 2.3.15? How to get around this problem in 2.3.16?

Answer 1

The fix still present in Struts 2.3.16, but moved to the DefaultFileManager::fileNeedsReloading(URL fileUrl).

With respect to ClassLoader::getResource(String name) can return null value. See description of javadoc

A URL object for reading the resource, or null if the resource could not be found or the invoker doesn't have adequate privileges to get the resource.