Question

I created a class and overridden the equals() method. When I use assertTrue(obj1.equals(obj2)), it will pass the test; however, assertEquals(obj1, obj2) will fail the test. Could someone please tell the reason why?

Answer 1

My guess is that you haven’t actually overridden equals – that you’ve overloaded it instead. Use the @Override annotation to find this sort of thing out at compile time.

In other words, I suspect you’ve got:

public boolean equals(MyClass other)

where you should have:

@Override // Force the compiler to check I'm really overriding something
public boolean equals(Object other)

In your working assertion, you were no doubt calling the overloaded method as the compile-time type of obj1 and obj2 were both MyClass (or whatever your class is called). JUnit’s assertEquals will only call equals(Object) as it doesn’t know any better.