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 can create your generic Java 8 utility method to concat any number of lists.

@SafeVarargs
public static  List concat(List... lists) {
    return Stream.of(lists).flatMap(List::stream).collect(Collectors.toList());
}