Java - Use annotations and intercept methods?

Question

Is there a simple way to intercept methods in java. I need to add an annotation to required methods so that a piece of logic gets called before going through the method.

public void verifyActivity() {
   // Asset if you are on a wrong page
}

@VerifyActivity
public void testLogin() {
   // Login for my automate test
}

@VerifyActivity
public void testSomethingElse() {
   // Test some other UI Automation stuff
}

EDIT:

The recommended guice library for android apps does not contain AOP. Is it possible to achieve this using reflection without adding any libraries?

Answer 1

Guice provides easy way of implementing annotations. Check this out.

http://code.google.com/p/google-guice/wiki/AOP

http://code.google.com/p/google-guice/

Answer 2

As sid malani said Google Guice is great for this. In general you want to read up on aspect oriented programming tutorials ... There is a nice tool called JMangler that may be of use as well

Answer 3

You can use reflection if you've coded to interfaces through dynamic proxies.

Answer 4

I doubt that it can be nicely done without any 3rd party libs.

There is a library called cglib, which is capable of such things.

Basically it will create a subclass of the intercepted class at runtime. You'll be able to "override" methods by implementing an InvocationHandler, which will act as a proxy when any of the superclass methods being called.