Need Help : compare element in list

Question

Hi all,
I have a list of set : [[abc] [ac] [abc] [a]]
I want to compare a set with each other. For example:[abc] with [ac] = [ac] // result is [ac] and newSet will hold the result
[ac] with [ac] = [ac] 
[ac] with [abc] = [ac]
[ac] with = [ac][b]
[ac][b] with [a] = [c][b]
My problem is how to hold the result to compare another set.
Below is my code…I’m stuck here for one day…please show me what should I do..
     public static void intersect(List listSet2) {  // listSet2 ; [[abc] [ac] [abc] [a]]
          TreeSet set = new TreeSet(((Set)listSet2.get(0)));          
          for (int i=1; i < listSet2.size(); i++) {
               TreeSet newSet = new TreeSet();
               Iterator it = ((Set) listSet2.get(i)).iterator();
                    while (it.hasNext()){
                         Object o = it.next();
                         if(set.contains( o ) ){// I want set hold the latest set
                              newSet.add( o );
          System.out.println("Intersection : " + newSet);

Answer 1

Hi..
I had settle my first problem to hold the latest result but I have the problem when the result find to next set which contains different value...it will return [ ]...actually I want it do union if find different value...I have no idea to settle it....can anyone give me some idea....tq very much
[abc] with [ac] = [ac]
will hold the result
[ac] with [ac] = [ac]
[ac] with [abc] = [ac]three above are settle
[ac] with = [ac][b]
it return [ ]
[ac] with [a] = [c][b]
Below is my code :     public static void intersect(List listSet2) {
          Set inter = new HashSet((Set)listSet2.get(0));
          Set union = new HashSet();
          for (int i=1; i < listSet2.size(); i++){
               inter.retainAll((Set)listSet2.get(i));
               System.out.println("Inter " + inter);