Java tutorial
//package com.java2s; import java.util.*; public class Main { public static Collection or(Collection collection1, Collection collection2) { Vector completeList = new Vector(collection1); if (collection2 == null) return collection1; Iterator i = collection2.iterator(); // Do the long way tro make sure no dups while (i.hasNext()) { Object addlItem = i.next(); if (collection1.contains(addlItem) == false) { completeList.addElement(addlItem); } } return completeList; } }