Package de.digitalcollections.workflow.engine.messagebroker

Class MessageBroker

java.lang.Object

de.digitalcollections.workflow.engine.messagebroker.MessageBroker

public class MessageBroker
extends Object

A MessageBroker provides a high level API to interact with an MessageBroker like RabbitMQ and provides the framework engines logic for message operations like sending, retrieving or rejecting for messages.

Method Summary

Modifier and Type	Method	Description
void	ack(Message message)	Acknowledges a message to remove it from the queue.
void	fail(Message message)
MessageBrokerConfig	getConfig()
Message	receive()	Gets one message from the input queue but does not acknowledge it.
Message	receive(String queueName)	Gets one message from the queue but does not acknowledge it.
boolean	reject(Message message)	Rejects a messaging and takes care of proper dead lettering, retries and, if the message failed too often, routing to the failed queue.
void	send(Message message)	Sends a message to the default output queue as JSON document.
void	send(String routingKey, Message message)	Sends a message to a certain queue as JSON document.
void	send(String routingKey, Collection<Message> messages)	Sends multiple messages to a certain queue as JSON documents.

Methods inherited from class java.lang.Object

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

Method Detail

send

public void send(Message message)
          throws IOException

Sends a message to the default output queue as JSON document.

Parameters:

message - the message to send.

Throws:

IOException - if sending the message fails.

send

public void send(String routingKey,
                 Message message)
          throws IOException

Sends a message to a certain queue as JSON document.

Parameters:

routingKey - the routing key for the queue to send the message to (usually the queue name).

message - the message to send.

Throws:

IOException - if sending the message fails.

send

public void send(String routingKey,
                 Collection<Message> messages)
          throws IOException

Sends multiple messages to a certain queue as JSON documents. The messages are sent in the same order as returned by the iterator over messages.

Parameters:

routingKey - the routing key for the queue to send the message to (usually the queue name).

messages - the messages to send.

Throws:

IOException - if sending a message fails.

receive

public Message receive(String queueName)
                throws IOException

Gets one message from the queue but does not acknowledge it. To do so, use ack(Message).

Parameters:

queueName - the queue to receive.

Returns:

the received message.

Throws:

IOException - if communication with RabbitMQ failed.

receive

public Message receive()
                throws IOException

Gets one message from the input queue but does not acknowledge it. To do so, use ack(Message).

Returns:

the received message.

Throws:

IOException - if communication with RabbitMQ failed.

ack

public void ack(Message message)
         throws IOException

Acknowledges a message to remove it from the queue.

Parameters:

message - the message to acknowledge.

Throws:

IOException - if communication with RabbitMQ failed.

reject

public boolean reject(Message message)
               throws IOException

Rejects a messaging and takes care of proper dead lettering, retries and, if the message failed too often, routing to the failed queue.

Parameters:

message - the message to reject

Throws:

IOException - if communication with RabbitMQ failed

fail

public void fail(Message message)
          throws IOException

Throws:

IOException

getConfig

public MessageBrokerConfig getConfig()