how to remove arraylist duplicate values

Question

I am performing some maintenance tasks on an old system. I have an arraylist that contains following values:

a,b,12
c,d,3
b,a,12
d,e,3
a,b,12

Answer 1

Create a class to wrap around a row string (triplet) to provide your equality semantics. Implement the equals() and hashCode() methods. Then use the HashSet method to remove duplicates.