Remove duplicates in array

import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.List; 
import java.util.Set;

public class ArrayListDuplicateDemo{
  public static void main(String args[]){
    List<Integer> primes = new ArrayList<Integer>();
    
        primes.add(2);
        primes.add(3);
        primes.add(5);
        primes.add(7);  //duplicate
        primes.add(7);
        primes.add(11);
        
        System.out.println("list of prime numbers : " + primes);
        
        Set<Integer> primesWithoutDuplicates = new LinkedHashSet<Integer>(primes);
        primes.clear();
        
        primes.addAll(primesWithoutDuplicates);
         
        System.out.println("list of primes without duplicates : " + primes);
   }
}