Package org.apache.qpid.protonj2.client

Interface Receiver

All Superinterfaces:

AutoCloseable, Link<Receiver>

All Known Implementing Classes:

ClientReceiver

public interface Receiver
extends Link<Receiver>

AMQP Receiver that provides an interface to receive complete Deliveries from a remote peer. Deliveries that are returned from the receive() methods will be complete and can be read immediately without blocking waiting for additional delivery data to arrive.

See Also:

StreamReceiver

Method Summary

Modifier and Type	Method	Description
Receiver	addCredit(int credits)	Adds credit to the Receiver link for use when there receiver has not been configured with a credit window.
Future<Receiver>	drain()	Requests the remote to drain previously granted credit for this Receiver link.
long	queuedDeliveries()	Returns the number of Deliveries that are currently held in the Receiver delivery queue.
Delivery	receive()	Blocking receive method that waits forever for the remote to provide a Delivery for consumption.
Delivery	receive(long timeout, TimeUnit unit)	Blocking receive method that waits the given time interval for the remote to provide a Delivery for consumption.
Delivery	tryReceive()	Non-blocking receive method that either returns a message is one is immediately available or returns null if none is currently at hand.

Methods inherited from interface org.apache.qpid.protonj2.client.Link

address, client, close, close, closeAsync, closeAsync, connection, desiredCapabilities, detach, detach, detachAsync, detachAsync, offeredCapabilities, openFuture, properties, session, source, target

Method Detail

addCredit

Receiver addCredit(int credits)
            throws ClientException

Adds credit to the Receiver link for use when there receiver has not been configured with a credit window. When credit window is configured credit replenishment is automatic and calling this method will result in an exception indicating that the operation is invalid.

If the Receiver is draining and this method is called an exception will be thrown to indicate that credit cannot be replenished until the remote has drained the existing link credit.

Parameters:

credits - The number of credits to add to the Receiver link.

Returns:

this Receiver instance.

Throws:

ClientException - if an error occurs while attempting to add new Receiver link credit.

receive

Delivery receive()
          throws ClientException

Blocking receive method that waits forever for the remote to provide a Delivery for consumption.

Receive calls will only grant credit on their own if a credit window is configured in the ReceiverOptions which is done by default. If the client application has configured no credit window than this method will not grant any credit when it enters the wait for new incoming messages.

Returns:

a new Delivery received from the remote.

Throws:

ClientException - if the Receiver or its parent is closed when the call to receive is made.

receive

Delivery receive(long timeout,
                 TimeUnit unit)
          throws ClientException

Blocking receive method that waits the given time interval for the remote to provide a Delivery for consumption. The amount of time this method blocks is based on the timeout value. If timeout is equal to -1 then it blocks until a Delivery is received. If timeout is equal to zero then it will not block and simply return a Delivery if one is available locally. If timeout value is greater than zero then it blocks up to timeout amount of time.

Receive calls will only grant credit on their own if a credit window is configured in the ReceiverOptions which is done by default. If the client application has not configured a credit window or granted credit manually this method will not automatically grant any credit when it enters the wait for a new incoming Delivery.

Parameters:

timeout - The timeout value used to control how long the receive method waits for a new Delivery.

unit - The unit of time that the given timeout represents.

Returns:

a new Delivery received from the remote.

Throws:

ClientException - if the Receiver or its parent is closed when the call to receive is made.

tryReceive

Delivery tryReceive()
             throws ClientException

Non-blocking receive method that either returns a message is one is immediately available or returns null if none is currently at hand.

Returns:

a new Delivery received from the remote or null if no pending deliveries are available.

Throws:

ClientException - if the Receiver or its parent is closed when the call to try to receive is made.

drain

Future<Receiver> drain()
                throws ClientException

Requests the remote to drain previously granted credit for this Receiver link.

Returns:

a Future that will be completed when the remote drains this Receiver link.

Throws:

ClientException - if an error occurs while attempting to drain the link credit.

queuedDeliveries

long queuedDeliveries()
               throws ClientException

Returns the number of Deliveries that are currently held in the Receiver delivery queue. This number is likely to change immediately following the call as more deliveries arrive but can be used to determine if any pending Delivery work is ready.

Returns:

the number of deliveries that are currently buffered locally.

Throws:

ClientException - if an error occurs while attempting to fetch the queue count.