Java – EasyMock: How to create a mock of a genericized class without a warning

easymockgenericsjavamocking

The code

private SomeClass<Integer> someClass;
someClass = EasyMock.createMock(SomeClass.class);

gives me a warning "Type safety: The expression of type SomeClass needs unchecked conversion to conform to SomeClass<Integer>".

Best Answer

AFAIK, you can't avoid the unchecked warning when a class name literal is involved, and the SuppressWarnings annotation is the only way to handle this.

Note that it is good form to narrow the scope of the SuppressWarnings annotation as much as possible. You can apply this annotation to a single local variable assignment:

public void testSomething() {

    @SuppressWarnings("unchecked")
    Foo<Integer> foo = EasyMock.createMock(Foo.class);

    // Rest of test method may still expose other warnings
}

or use a helper method:

@SuppressWarnings("unchecked")
private static <T> Foo<T> createFooMock() {
    return (Foo<T>)EasyMock.createMock(Foo.class);
}

public void testSomething() {
    Foo<String> foo = createFooMock();

    // Rest of test method may still expose other warnings
}
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