Question

The title speaks for itself. The language is Java.

Answer 1

Yes, there is. This is however a tedious and expensive work. You need to crawl through all class files and all JAR files with help of ClassLoader#getResources() and a shot of java.io.File and load all classes of it with help of Class#forName() and finally check if the method is there by Class#getMethod().

However, there are 3rd party API’s which can take the tedious work from hands, but it is still expensive, because loading a class would cause its static initializers being executed.

A cleaner way is to make use of annotations and annotate the methods in question and then make use of libraries which searches for classes/methods/fields based on the annotations, such as Google Reflections.

On the other hand, if the entire package name or the JAR file name is known beforehand, then the work will be less tedious and expensive (no need to do stuff recursively nor to load the all of the classes of entire classpath).

Update: I remember, I ever wrote sample code to achieve something like that, you can find it here. It’s good to start with, you only need to change it a bit to check the method.