How to merge two ArrayLists without duplicates? [duplicate]

Question

I have two arrayLists

ArrayList one = {A, B, C, D, E} ArrayList two = {B, D, F, G}   

I want to have my final ArrayList which will have All the elements of one and the elements which are only in two and not in one.

So ArrayList final = {A, B, C, D, E, F, G}.

How can I do this?

Answer 1

Either:

Set<Foo> fooSet = new LinkedHashSet<>(one); fooSet.addAll(two); List<Foo> finalFoo = new ArrayList<>(fooSet); 

or

List<Foo> twoCopy = new ArrayList<>(two); twoCopy.removeAll(one); one.addAll(twoCopy); 

Answer 2

for (Object x : two){    if (!one.contains(x))       one.add(x); } 

assuming you don't want to use the set suggested in the comment. If you are looking for something fancier than this please clarify your question.