Is there a concurrent List in Java's JDK?

There is a concurrent list implementation in java.util.concurrent. CopyOnWriteArrayList in particular.

ConcurrentLinkedQueue

If you don't care about having index-based access and just want the insertion-order-preserving characteristics of a List, you could consider a java.util.concurrent.ConcurrentLinkedQueue. Since it implements Iterable, once you've finished adding all the items, you can loop over the contents using the enhanced for syntax:

Queue<String> globalQueue = new ConcurrentLinkedQueue<String>();

//Multiple threads can safely call globalQueue.add()...

for (String href : globalQueue) {
    //do something with href
}

You can very well use Collections.synchronizedList(List) if all you need is simple invocation synchronization:

 List<Object> objList = Collections.synchronizedList(new ArrayList<Object>());