Java.lang.Void and Void

java.lang.Voidis analogous to java.lang.Integer . is Integer A-a-boxing values of the primitive type. is int A-a-on-the- Void boxing values of the Primitive type void .

"But wait, void doesn ' t has any possible values!"

right! That's what makes java.lang.Void "uninstantiable".:)

It's a nice feature of the Java type system, every primitive type has a boxed equivalent. int Integer has, long have Long , has ... and byte Byte void Void has. It would be weird and asymmetrical if Void didn ' t exist.

"So what's the difference between and java.lang.Void void ?"

Easy. is void a primitive type. Void is a reference type that inherits from Object . They ' re similar in that neither of them have any possible values; But nevertheless they is the very different types, from the type system's point of view.

"But I don ' t has any with for in Void my programs."

and I don ' t has any with the in GarbageCollectorMXBean mine. Some features don ' t have non-obscure uses. That ' s okay.

The only point Void Void.TYPE was to hold and which is the sort of void.class . If you had a reflective reference to a method, then returns void , and you get the its return type, it ' ll return Void.TYPE .

Java.lang.Void and Void