Arrays.asList()

Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception. If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Arrays.asList().

new ArrayList(Arrays.asList(myArray)) copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Collections.addAll(myList, myStringArray) is essentially the same as new ArrayList(Arrays.asList(myArray)) .