CODEWITHSUNDEEP
javaannotations
Prasad
Prasad

Reputation: 529

Getting annotation value of calling method

I want to get a value in annotation from method that is calling another method and that needs to be used with annotation used in called method.

Example

@MyAnnotation(id="method-invoker")
public void invoker(){
     executor();
}

@ChildMethod
public void executor(){
}

In above example I want to get value set in id field in @MyAnnotation when handling @ChildMethod annotation.

How can I do this?

Upvotes: 1

Views: 1518

Answers (1)

AlexR
AlexR

Reputation: 115328

First you have to get the stack trace, then extract caller's name from it, then get the Method and get its annotation:

String id = getClass().getMethod(new Throwable().getStackTrace()[1].getMethodName()).getAnnotation(MyAnnotation.class).id();

(obviously it is a bad style to perform so many calls sequentially in one line, but it is ok for example).

But this method is limited. It does not support methods overloading. For example if you have 2 methods called invoker() that have different signature in one class you cannot distinguish between them using pure reflection API.

Fortunately I implemented library named CallStack that can do this: https://github.com/alexradzin/callstack

Using CallStack you can say:

CallStack.getCallStack().getFunction().getAnnotation(MyAnnotation.class).id()

Upvotes: 4

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