When overriding can comparing object ever be null?

Question

When overriding equals method for an object can obj below ever be null , if so what are the circumstances?

@Override
 public boolean equals(Object obj) {

Answer 1

Yes, equals() should handle null and in that case it should return false as documented in Object.equals() :

For any non-null reference value x , x.equals(null) should return false .

Of course if x is null x.equals(null) won't return true but it will throw NullPointerException . If you need to compare two possibly null references look at Objects.equals(Object, Object) :

Objects.equals(x, x);

The above is always true , even if x == null .

Answer 2

It's a public method. It can be null whenever a caller passes a null value into it. You have to handle that case appropriately.