Please need code, Don't resend the ones on cheggs, as they were incorrect, Java mars

Question#3: 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: 1-Source code. 2-Screenshots of the output