I think the official documentation
gives you the answer to this one (albeit in a fairly nonspecific way):
This method is the dynamic equivalent of the Java language instanceof
operator.
I take that to mean that isInstance() is primarily
intended for use in code dealing with type reflection at runtime. In
particular, I would say that it exists to handle cases where you might not
know in advance the type(s) of class(es) that you want to check for
membership of in advance (rare though those cases probably are).
For instance, you can use it to write a method that checks to see if
two arbitrarily typed objects are assignment-compatible, like:
publicboolean areObjectsAssignable(Object left,Object right){return left.getClass().isInstance(right);}In general, I‘d say that using instanceof should be
preferred whenever you know the kind of class you want to check against in
advance. In those very rare cases where you do not, use
isInstance() instead.
For instanceof you need to know the exact class at compile
time.
if(foo instanceofThisClassIKnowRightNow)...For isInstance the class is decided at run time. (late
binding) e.g.
if(someObject.getClass().isInstance(foo))...When to use Class.isInstance() & when to use instanceof
operator?,布布扣,bubuko.com
When to use Class.isInstance() & when to use instanceof
operator?