Question

Say I have the following generic class:

public class Foo<T extends Bar> {
   // stuff
}

Is it possible to specify a default type(Baz, for instance), which would act as T if no T were passed in?

Answer 1

No. See “Type Variables” in the Java Language Specification.

That said, you can provide subclasses which accomplish a similar purpose:

public class Foo<T extends Bar> { ... }

public class FooDefault extends Foo< Baz > { ... }