类参数的easymock方法匹配器

Question

I have a method with signature as follows:

    public <T extends S> T foo(final Class<T> clazz){
       .....
       .....
    }

How do I mock this method in easymock?

I tried following two lines in my test class but still the expected object is not returned, so I get NullPointerException.

    Capture<Class<MyClass>> classCapture = new Capture<Class<MyClass>>();
            expect(someObject.foo(EasyMock.capture(classCapture))).andReturn(testObject);

And testObject is initialized in the test class, which I want to get returned when

    foo() 

is called. Where am I doing wrong?

Answer 1

I'm not sure why you want to capture the variable in this instance, but your problem is the way you typed your command means you are looking for a method foo() without any arguments.

You need to you need to use and() to chain the capture and the argument matcher requirements for the method call:

expect(someObject.foo(EasyMock.and(
                            EasyMock.capture(classCapture),
                            anyObject()))
                      )
            .andReturn(testObject);

Then after you call your mock in replay mode you can get the captured argument back with capture.getValue()

    replay(someObject);

    assertSame(testObject, someObject.foo(MyClass.class));

    assertEquals(MyClass.class, classCapture.getValue());