title: Java merge 2 collections in O(1)
body: <p>I need to be able to merge 2 large collections into 1. Which collection type can I use best? I don't need random access to the individual elements. Usually I'd go for a linkedlist, however I can't merge 2 linkedlist in Java with a runtime of O(1), which could be done in many other languages, since I'll have to copy each element to the new list.</p>
  
  <p>Edit: Thank you for all your answers. Your answers were all very helpful, and I managed to get the job done. Next time I will use my own implementation of a linked list to begin with. </p>