Can we load only those classes which we have annotated with our custom annotation?

Question

I came across one question regarding custom annotation. Question :- Suppose we have created a custom annotation, and we applied it to some classes(Suppose in our application/module we have total of 10 classes, and we have applied custom annotation only on 5 classes, rest 5 are annotated with normal inbuilt annotation like @Autowiring, @COmponent and many more) in our app.

Now, when I load the whole application, will it be possible to load or we can say instantiate only those classes which I have annotated with my custom annotation.

Will it be possible?

Answer 1

Assuming

@MyAnnotation
public class MyClass {
   ...
}

Then

if (MyClass.class.isAnnotationPresent(MyAnnotation.class)) {
   MyClass myObj = MyClass.newInstance();
}

Will conditionally instantiate an annotated class.

Answer 2

using entryClass.getAnnotation() we can load the class which we custom annotated. String jarFile = "path/to/jarfile.jar"; DexClassLoader classLoader = new DexClassLoader( jarFile, "/tmp", null, getClass().getClassLoader()); Class<?> myClass = classLoader.loadClass("MyClass");