do in java and make sure to test the code with some inputs

Write a simple class called ArrayListSubject that maintains an arraylist of objects. It provides two operations void append(Object obj); //append the object to the end of the arraylist void delete(Object obj); /remove the object from the arraylist Use the observer pattern to define an observer that simply prints "an item being deleted" when the delete operation is called on ArrayListSubject. For all these questions, test your code with some inputs. You have to submit the following to the blackboard