java - Memory management : how to reset a list correctly -

In terms of the effect and effect on the garbage collector, I would like to know what is the difference between those two implementations: Protected List & lt; T & gt; _data = new arreelist & lt; T & gt; (); // I want to reset this list using another. Try first: Public Zero Set (list & lt; T & gt; newData) {_data = newData; } / / I want to reset this list using someone else Second attempt: Public Zero Set (List & lt; T & gt; New Data) {_data.clear (); _data.addAll (newData); }

In addition, if there is a functional difference, please tell me!

Replaces the context of a list with the one provided by the previous caller. If the old list has not been reached from anywhere else, then it is eligible for GC.

Uses the current list of second item, and it copies all the items in the list of the caller's references, if it increases the size of the archive, then assigns a large array internally to it. (Small arrays are collected).

The access to the item itself is not to be changed; In both versions the list has been given the reason for referencing the same item.

The first is slightly faster than usual, because you are changing the single reference, it is less work than copying a bunch of references from one list to another.

The second, however, is generally better than a sign point of view. Imagine ...

  yourThingie.set (myItems); MyItems.add (objectYouNeverWouldHaveAllowed);   
 With the first version,  _data  now