Which implementation of List to use?

Question

In my program I often use collections to store lists of objects. Currently I use ArrayList to store objects. My question is: is this a best choice? May be its better to use LinkedList? Or something else?

Criteria to consider are:

• Memory usage
• Performance

Operations which I need are:

• Add element to collection
• Iterate through the elements

Any thoughts?

Update: my choice is : ArrayList :) Basing on this discussion as well as the following ones:

• When to use LinkedList over ArrayList?
• List implementations: does LinkedList really perform so poorly vs. ArrayList and TreeList?

Answer 1

I always default to ArrayList, and would in your case as well, except when

• I need thread safety (in which case I start looking at List implementations in java.util.concurrent)
• I know I'm going to be doing lots of insertion and manipulation to the List or profiling reveals my usage of an ArrayList to be a problem (very rare)

As to what to pick in that second case, this SO.com thread has some useful insights: List implementations: does LinkedList really perform so poorly vs. ArrayList and TreeList?