Why scan the classpath? There are various patterns that are often used in enterprise Java applications that require scanning of classpath and getting the list of all classes that are present in the application.
For example, if you want to discover all classes with a certain annotation (such as @Component in Spring Framework) to process them in a special way, you need a way to go over all classes in your application and select some of them based on which annotations they have.
However, neither Java SE nor Android have built-in facilities to safely get the list of all classes in your application in runtime. The reason for that is the theory behind classloaders in Java – the ability to go over all classes is neither needed in classic OOP nor feasible for all theoretically possible classloader implementations. However, in practice, scanning classpath and discovering the classes you need is quite possible in most cases, both in your web app and on Android. This is always going to be more or less a hack, but if it has been useful in web applications, it can also be useful in Android apps – with some caution, of course.
Thus, in this article I will show and explain a piece of code that does exactly that – scans your classpath and gives you the ability to go over all classes in your app.