Package org.apache.curator.framework.recipes.queue

Class BlockingQueueConsumer<T>

  • All Implemented Interfaces:
    QueueConsumer<T>, org.apache.curator.framework.state.ConnectionStateListener
    public class BlockingQueueConsumer<T>
extends java.lang.Object
implements QueueConsumer<T>
    Utility - a queue consumer that provides behavior similar to a BlockingQueue

    • Constructor Summary

      Constructors 
      Constructor Description
      BlockingQueueConsumer​(org.apache.curator.framework.state.ConnectionStateListener connectionStateListener)
      Creates with capacity of Integer.MAX_VALUE
      BlockingQueueConsumer​(org.apache.curator.framework.state.ConnectionStateListener connectionStateListener, int capacity)  
      BlockingQueueConsumer​(org.apache.curator.framework.state.ConnectionStateListener connectionStateListener, java.util.concurrent.BlockingQueue<T> queue)
      Wrap the given blocking queue

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void consumeMessage​(T message)
      Process a message from the queue
      int drainTo​(java.util.Collection<? super T> c)
      Removes all available elements from this queue and adds them to the given collection.
      java.util.List<T> getItems()
      Return any currently queued items without removing them from the queue
      int size()
      Returns the number of currently queue items
      void stateChanged​(org.apache.curator.framework.CuratorFramework client, org.apache.curator.framework.state.ConnectionState newState)  
      T take()
      Take the next item from the queue, blocking until there is an item available
      T take​(int time, java.util.concurrent.TimeUnit unit)
      Take the next item from the queue, waiting up to the specified time for an available item.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

      • Methods inherited from interface org.apache.curator.framework.state.ConnectionStateListener

        doNotDecorate

    • Constructor Detail

      • BlockingQueueConsumer

        public BlockingQueueConsumer​(org.apache.curator.framework.state.ConnectionStateListener connectionStateListener)
        Creates with capacity of Integer.MAX_VALUE
        Parameters:
        connectionStateListener - listener for connection state changes

      • BlockingQueueConsumer

        public BlockingQueueConsumer​(org.apache.curator.framework.state.ConnectionStateListener connectionStateListener,
                             int capacity)
        Parameters:
        capacity - max capacity (i.e. puts block if full)
        connectionStateListener - listener for connection state changes

      • BlockingQueueConsumer

        public BlockingQueueConsumer​(org.apache.curator.framework.state.ConnectionStateListener connectionStateListener,
                             java.util.concurrent.BlockingQueue<T> queue)
        Wrap the given blocking queue
        Parameters:
        queue - queue to use
        connectionStateListener - listener for connection state changes

    • Method Detail

      • consumeMessage

        public void consumeMessage​(T message)
                    throws java.lang.Exception
        Description copied from interface: QueueConsumer
        Process a message from the queue
        Specified by:
        consumeMessage in interface QueueConsumer<T>
        Parameters:
        message - message to process
        Throws:
        java.lang.Exception - any errors

      • getItems

        public java.util.List<T> getItems()
        Return any currently queued items without removing them from the queue
        Returns:
        items (can be empty)

      • size

        public int size()
        Returns the number of currently queue items
        Returns:
        currently queue item count or 0

      • take

        public T take()
       throws java.lang.InterruptedException
        Take the next item from the queue, blocking until there is an item available
        Returns:
        the item
        Throws:
        java.lang.InterruptedException - thread interruption

      • take

        public T take​(int time,
              java.util.concurrent.TimeUnit unit)
       throws java.lang.InterruptedException
        Take the next item from the queue, waiting up to the specified time for an available item. If the time elapses, null is returned.
        Parameters:
        time - amount of time to block
        unit - time unit
        Returns:
        next item or null
        Throws:
        java.lang.InterruptedException - thread interruption

      • drainTo

        public int drainTo​(java.util.Collection<? super T> c)
        Removes all available elements from this queue and adds them to the given collection. This operation may be more efficient than repeatedly polling this queue. A failure encountered while attempting to add elements to collection c may result in elements being in neither, either or both collections when the associated exception is thrown. Attempts to drain a queue to itself result in IllegalArgumentException. Further, the behavior of this operation is undefined if the specified collection is modified while the operation is in progress.
        Parameters:
        c - the collection to transfer elements into
        Returns:
        the number of elements transferred
        Throws:
        java.lang.UnsupportedOperationException - if addition of elements is not supported by the specified collection
        java.lang.ClassCastException - if the class of an element of this queue prevents it from being added to the specified collection
        java.lang.NullPointerException - if the specified collection is null
        java.lang.IllegalArgumentException - if the specified collection is this queue, or some property of an element of this queue prevents it from being added to the specified collection

      • stateChanged

        public void stateChanged​(org.apache.curator.framework.CuratorFramework client,
                         org.apache.curator.framework.state.ConnectionState newState)
        Specified by:
        stateChanged in interface org.apache.curator.framework.state.ConnectionStateListener