How do I join two lists in Java?

Question

Conditions: do not modify 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:

List<String> newList = new ArrayList<String>(); newList.addAll(listOne); newList.addAll(listTwo); 

Answer 1

In Java 8:

List<String> newList = Stream.concat(listOne.stream(), listTwo.stream())                              .collect(Collectors.toList());