To determine the class of an object simply call:
someObject.getClass()
You can abbreviate this to someObject.class in most cases. However, if you use this on a Map it will try to retrieve the value with key 'class'. Because of this, I always use getClass() even though it's a little longer.
If you want to check if an object implements a particular interface or extends a particular class (e.g. Date) use:
(somObject instanceof Date)
or to check if the class of an object is exactly a particular class (not a subclass of it), use:
(somObject.getClass() == Date)
Just to add another option to Dónal's answer, you can also still use the good old java.lang.Object.getClass() method.
You can use the Membership Operator isCase() which is another groovy way:
assert Date.isCase(new Date())
somObject instanceof Date
should be
somObject instanceOf Date
Simple groovy way to check object type:
somObject in Date
Can be applied also to interfaces.
Source: Stackoverflow.com