Why does this Java method appear to have two return types?

Question

public <E extends Foo> List<E> getResult(String s);

where Foo is my own class.

What is the return type of this method? Why does it seem to have two return types?

Answer 1

No, you don't have two return types. It's a generic method you are seeing.

• <E extends Foo> → You are declaring a generic type for your method;
• List<E> → This is your return type.

Your method can have a generic type E which is a subclass of Foo. The return type of the method is a List<Foo-or-any-subtype-of-Foo>.

Answer 2

The return type is List<E>. The clause <E extends Foo> is not a return type; it is a generic type declaration, specifying that the particular type E must be a Foo (or a subclass of Foo). This is standard syntax for declaring a generic method.

Answer 3

Take a look at the Java documentation pertaining to generics.

<E extends Foo> // declares the bounds for the generic type `E`
List<E> // declares the return value

The return type of the method is List<E>.