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

Almost of answers suggest to use an ArrayList.

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

Prefer to use a LinkedList for efficient add operations.

ArrayList add is O(1) amortized, but O(n) worst-case since the array must be resized and copied. While LinkedList add is always constant O(1).

more infos https://stackoverflow.com/a/322742/311420