How do I join two lists in Java?

Question

Conditions: do not modifiy the original lists; JDK only, no external libraries. Bonus points for a one-liner or a JDK 1.3 version.

Is there a simpler way than:

Answer 1

You could do it with a static import and a helper class

nb the generification of this class could probably be improved

public class Lists {

   private Lists() { } // can't be instantiated

   public static List join(List... lists) {
      List result = new ArrayList();
      for(List list : lists) {
         result.addAll(list);
      }
      return results;
   }

}

Then you can do things like

import static Lists.join;
List result = join(list1, list2, list3, list4);