java - Avoid Duplicate Records - HashSet -

i'm trying multiple objetcs of dto arraylist through for loop. once objects added, avoiding duplicates i'm converting arraylist hashset avoid duplicate records.

code snippet -

....  arraylist list = new arraylist();  for( .... ){    class factory = dto.getclass();   object bean = factory.newinstance();   list.add(bean); }  return new arraylist(new hashset(list)); 

but returned arraylist has duplicates, want avoid.

even if 2 instances of dto contain same values, considered different hashset. considered equal, dto1.equals(dto2) (and dto2.equals(dto1)) must return true. must override object.equals() method in dto in order specify when 2 dto instances equal. , when override equals(), must override hashcode(). 2 equal objects must have same hashcode.

read documentation of 2 methods, , use ide generate 2 methods if don't know how implement them.