The java.util.concurrent package includes a number of additions to the Java Collections Framework. These are most easily categorized by the collection interfaces provided:
Java Concurrent Collection Classes
BlockingQueue – an interface that is at the base of all Queue based concurrent collections. While adding an element to a BlockingQueue, if there is no space it can wait till it becomes available and when retrieving, it will wait till an element is available if it is empty.
ArrayBlockingQueue – a blocking queue class based on bounded Java Array. Once instantiated, cannot be resized.
SynchronousQueue – a blocking queue class with capacity of zero always.
PriorityBlockingQueue – a priority queue based blocking queue. It is an unbounded concurrent collection.
LinkedBlockingQueue – an optionally bounded Java concurrent collection. Orders elements based on FIFO order.
DelayQueue – a queue where only delay expired elements can be taken out. Its an unbounded concurrent collection.
BlockingDeque – an interface that extends BlockingQueue and adds the operations of Deque.
LinkedBlockingDeque – an implementation class of BlockingDequeue.
TransferQueue – a Java concurrent collection interface that extends BlockingQueue and adds method where the producer will wait for the consumer to receive elements.
LinkedTransferQueue – an implementation class of TransferQueue.
ConcurrentMap – a Java concurrent collection interface and a type of Map which provides thread safety and atomicity guarantees.
ConcurrentHashMap – an implementation class of ConcurrentMap.
ConcurrentNavigableMap – a Java concurrent collection interface that extends ConcurrentMap and adds operations of NavigableMap.
ConcurrentSkipListMap – an implementation class of ConcurrentNavigableMap.
