Java tutorial
//package com.java2s; //it under the terms of the GNU Affero General Public License as published by import java.util.ArrayList; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Set; public class Main { public static <T> List<T> copyWithoutDublicates(List<T> l) { final List<T> result = new ArrayList<T>(); final Set<T> set = new HashSet<T>(); for (Iterator<T> it = l.iterator(); it.hasNext();) { final T t = it.next(); if (set.add(t)) { result.add(t); } } return result; } }