Determine if a Class implements a interface in Java

Question

I have a Class object. I want to determine if the type that the Class object represents implements a specific interface. I was wondering how this could be achieved?

I have the following code. Basically what it does is gets an array of all the classes in a specified package. I then want to go through the array and add the Class objects that implement an interface to my map. Problem is the isInstance() takes an object as a parameter. I can't instantiate an interface. So I am kind of at a loss with this. Any ideas?

Class[] classes = ClassUtils.getClasses(handlersPackage); for(Class clazz : classes) {     if(clazz.isInstance(/*Some object*/)) //Need something in this if statement     {         retVal.put(clazz.getSimpleName(), clazz);     } } 

Answer 1

You should use isAssignableFrom:

if (YourInterface.class.isAssignableFrom(clazz)) {     ... }