Description Robert M. Fuhrer 2005-04-14 15:26:00 EDT

IMethodBinding.getJavaElement() produces an IMethod that in the debugger looks like:

 unmodifiableList(java.util.List) (not open) [in Collections [in
Collections.class [in java.util [in
...\org.eclipse.jdt.ui.tests\testresources\rtstubs15.jar [in UnmodifiableList]]]]]

Note the "(not open)" indication.

The odd thing is that this IMethod is an intermediate result of a call to
ITypeBinding.getJavaElement(). The scenario: in analyzing

 <T> List<T> Collections.unmodifiableList(List<? extends T> list);

which has a method type parameter, the following method is called, passing an
IMethodBinding for Collections.unmodifiableList():

 void foo(IMethodBinding method) {
     ITypeBinding[] parmBindings= method.getTypeParameters();

     for(int idx= 0; idx < parmBindings.length; idx++) {
         ITypeBinding pb= parmBindings[idx];
         ITypeParameter tp= (ITypeParameter) pb.getJavaElement();
         // ...
     }
 }

In particular, a call is made to getJavaElement() on the ITypeBinding for the
method type parameter, namely, <T>. This call throws a JavaModelException, since
at some level JDT/Core claims that the method doesn't exist. Obviously, since
I'm starting with an IMethodBinding, the method *does* exist.

In case you're wondering, the IMethodBinding in question was returned by
IMethodBinding.getMethodDeclaration(), so it refers to the original generic
declaration, not some instantiation.

============================================================================
An easier way to reproduce is this:
- select the type parameter of Collections#unmodifiableList(..) in the editor
and open the ASTView
- set a breakpoint in JavaUI.revealInEditor(..) 
- expand the type binding for T and doubleclick the java element in the ASTView
(the last, green child)