CODEWITHSUNDEEP
javagenerics
j.doe
j.doe

Reputation: 87

Generic Return type for collections

Is is possible to have a generic return type such that collection can built with interface as well as implementation.

public static void main(String[] args) {
    List<Test1> list = ImmutableList.of(new Test1());
    List<ITest> test_return_1 = buildIntRange(list);
    List<Test1> test_return_2 = buildIntRange(list); //error
}

private static <K extends ITest> List<ITest> buildIntRange(List<K> test) {
    return ImmutableList.copyOf(test);
}

Upvotes: 3

Views: 71

Answers (1)

Louis Wasserman
Louis Wasserman

Reputation: 198471

Sure. Use the same signature as ImmutableList.copyOf, or just use ImmutableList.copyOf directly:

static <T> List<T> copyOf(Iterable<? extends T> collection)

Upvotes: 4

Related Questions