Question

I want to store different types in a Map like this:

public Map< String, Void > common;
MyClass object = new MyClass();
common.put( "Object1", object );

and then use it like this:

Void object = common.get( "Object1" );
( ( MyClass )object ).runAnyFunction();

This only works if I create my own empty class named Void and extends all classes I will put in the Map with Void. So problem solved, unless…

Isn’t there already a Void in Java? If I don’t create my own Void class is still works. Until I get to the casting where I try to .runAnyFunction(). Maybe if I tried to extend my classes with Void – but that only works with the Void I create, not Java’s Void.

It really comes down to if I really need to create my own empty Void class. Or if I can use Java’s own Void?

Answer 1

Why you don’t use Object? All Java classes a directly or indirectly subclasses from Object.

public Map< String, Object > common;