FastSet in java 8 which replaces? ArrayList?

Depends what's the container is supposed to do. If the order of insertion must be kept, it can be also a LinkedList. If it must be concurrent and ordered, ConcurrentSkipListSet.

 

If it's only concurrent, then CopyOnWriteArrayList got shitty performance, avoid to use it at any cost. Use ConcurrentHashMap.newKeySet() instead (which feed one column with boolean) in order to benefit from performance boost of CHMap.

 

All in one, it can be replaced in most of cases by a simple ArrayList (it's pretty rare to need concurrent or order, and even rarer to need both).

 

Once again, it depends what does your container.

Edited December 1, 20178 yr by Tryskell

Could use HashSet as well :p