Java isInstance vs instanceOf operator

Question

The whole generics thing is kinda throwing me for a loop, and more so the RTT.

Specificis? Ah well here\'s the gist:

enum QueryHelper {
  query1,
           


        

Answer 1

Class.isInstance() doesn't work like your code expects. It tests whether the object you pass to it is an instance of the class. In you code:

expectedReturn.isInstance(SomeRelatedClass.class)

The object you're passing is a Class object. Try this instead, which returns true:

Class.class.isInstance(SomeRelatedClass.class);

What you're probably looking for is Class.isAssignableFrom(), e.g.:

Object.class.isAssignableFrom(Class.class);

Means you can do this:

Class klass = ...;
Object o = klass;