Manoj Sahu,CITE,Bangalore

Hi dear 
I have a problem, please solve it,please give me solution within 1-2 days.I am a Student,MCA. ie I want to pass a list to a method and within method definition i removed the duplicate elements and when i returned the list to the calling method.when i compiled the code ,an  errors occurs that is:
 removeDuplicateFromArraListByMethod.java:21:<identifier> expected public String showNonDuplicateElements(list1)
---------------Below is my code, I tried---------------------

import java.util.*;
public class removeDuplicateFromArraListByMethod 
{
public static void main(String args[]) throws Exception
{
        nonDuplicateFound  ob=new nonDuplicateFound();
        ArrayList<String>list=new ArrayList<String>();
        list.add("A");
        list.add("A");
        list.add("A");
        list.add("B");
        list.add("B");
        list.add("C");

      ArrayList list3= ob.showNonDuplicateElements(list); 
        for(Object item:List3)
        System.out.println(item);
 }
 }   class nonDuplicateFound
      {
          public String showNonDuplicateElements(list1)
          {
        HashSet set=new HashSet(list1);

        ArrayList newList=new ArrayList(set);

        Collections.sort(newList);
        return newList;
        }
}   
 kindly solve my problem and send to <[email protected]>
                             Thanks & Regards
                                Manoj