ServletContainerInitializer Doesn't Find @HandlesTypes Classes Unless Directly Extended (Doc ID 1665019.1)

Last updated on JUNE 03, 2024

Applies to:

Symptoms

Using the Servlet 3.0 feature of creating a javax.servlet.ServletContainerInitializer,the javax.servlet.annotation.HandlesTypes annotation allows you to indicate which classes on the classpath to pass into the public void onStartup(final Set<Class> c, final ServletContext ctx) method. If we specify @HandlesType(MyHandledInterface.class),any class that directly implements MyHandledInterface will be provided to onStartup(c, ctx).

However,if we introduce an abstract class named AbstractHandledClass (for example) that implements MyInterface, and then create another class named MyHandledClass that extends AbstractHandledClass, MyHandledClass will not be provided in the set of classes given to onStartup(c, ctx). The set of classes (named c) will contain AbstractMyHandledClass, but it will not contain MyHandledClass.

Ideally we would expect MyHandledClass to be included in the set of classes because it does, in fact, implement MyInterface. It just does not implement it directly.But we notice on WLS 12.1.2 that MyHandledClass is not being provided in the set of classes given to onStartup(c, ctx).

Cause

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