How to sort an arraylist of objects java?

Question

So I want an arraylist of objects in java.

I have object1.number and object2.number, object3.number, etc... but those objects

Answer 1

To manipulate the entries of an ArrayList like that of a traditional array, use ArrayList.set(int, E).

http://docs.oracle.com/javase/1.5.0/docs/api/java/util/ArrayList.html#set%28int,%20E%29