Package com.amazon.sqs.javamessaging

Class SQSMessageConsumer

  • All Implemented Interfaces:
    javax.jms.MessageConsumer, javax.jms.QueueReceiver
    public class SQSMessageConsumer
extends Object
implements javax.jms.MessageConsumer, javax.jms.QueueReceiver
    A client uses a MessageConsumer object to receive messages from a destination. A MessageConsumer object is created by passing a Destination object to a message-consumer creation method supplied by a session.

    This message consumer does not support message selectors

    A client may either synchronously receive a message consumer's messages or have the consumer asynchronously deliver them as they arrive via registering a MessageListener object.

    The message consumer creates a background thread to prefetch the messages to improve the receive turn-around times.

    • Field Detail

      • PREFETCH_EXECUTOR_GRACEFUL_SHUTDOWN_TIME

        public static final int PREFETCH_EXECUTOR_GRACEFUL_SHUTDOWN_TIME
        See Also:
        Constant Field Values

      • closed

        protected volatile boolean closed

    • Method Detail

      • getQueue

        public javax.jms.Queue getQueue()
                         throws javax.jms.JMSException
        Gets the queue destination associated with this queue receiver, where the messages are delivered from.
        Specified by:
        getQueue in interface javax.jms.QueueReceiver
        Returns:
        a queue destination
        Throws:
        javax.jms.JMSException

      • getMessageListener

        public javax.jms.MessageListener getMessageListener()
                                             throws javax.jms.JMSException
        Gets the message consumer's MessageListener.
        Specified by:
        getMessageListener in interface javax.jms.MessageConsumer
        Returns:
        a message listener
        Throws:
        javax.jms.JMSException

      • setMessageListener

        public void setMessageListener​(javax.jms.MessageListener listener)
                        throws javax.jms.JMSException
        Sets the message consumer's MessageListener.
        Specified by:
        setMessageListener in interface javax.jms.MessageConsumer
        Parameters:
        listener - a message listener to use for asynchronous message delivery
        Throws:
        javax.jms.JMSException - If the message consumer is closed

      • receive

        public javax.jms.Message receive()
                          throws javax.jms.JMSException
        This call blocks indefinitely until a message is produced or until this message consumer is closed. When ConnectionState is stopped receive is paused.
        Specified by:
        receive in interface javax.jms.MessageConsumer
        Returns:
        the next message produced for this message consumer, or null if this message consumer is closed during the receive call
        Throws:
        javax.jms.JMSException - On internal error

      • receive

        public javax.jms.Message receive​(long timeout)
                          throws javax.jms.JMSException
        This call blocks until a message arrives, the timeout expires, or this message consumer is closed. A timeout of zero never expires, and the call blocks indefinitely.
        Specified by:
        receive in interface javax.jms.MessageConsumer
        Parameters:
        timeout - the timeout value (in milliseconds)
        Returns:
        the next message produced for this message consumer, or null if the timeout expires or this message consumer is closed during the receive call
        Throws:
        javax.jms.JMSException - On internal error

      • receiveNoWait

        public javax.jms.Message receiveNoWait()
                                throws javax.jms.JMSException
        Receives the next message if one is immediately available.
        Specified by:
        receiveNoWait in interface javax.jms.MessageConsumer
        Returns:
        the next message produced for this message consumer, or null if no message is available
        Throws:
        javax.jms.JMSException - On internal error

      • close

        public void close()
           throws javax.jms.JMSException
        Closes the message consumer.

        This will not return until receives and/or message listeners in progress have completed. A blocked message consumer receive call returns null when this consumer is closed.

        Since consumer prefetch threads use SQS long-poll feature with 20 seconds timeout, closing each consumer prefetch thread can take up to 20 seconds, which in-turn will impact the time on consumer close.

        This method may be called from a message listener's onMessage method on its own consumer. After this method returns the onMessage method will be allowed to complete normally, and the callback scheduler thread will be closing the message consumer.

        Specified by:
        close in interface javax.jms.MessageConsumer
        Throws:
        javax.jms.JMSException - On internal error.

      • getMessageSelector

        public String getMessageSelector()
                          throws javax.jms.JMSException
        This method is not supported.
        Specified by:
        getMessageSelector in interface javax.jms.MessageConsumer
        Throws:
        javax.jms.JMSException

      • stopPrefetch

        protected void stopPrefetch()
        This stops the prefetching

      • startPrefetch

        protected void startPrefetch()
        This starts the prefetching