com.sap.cds.services.utils.messaging.service

Class AbstractMessagingService

java.lang.Object

com.sap.cds.services.ServiceDelegator

com.sap.cds.services.utils.messaging.service.AbstractMessagingService

All Implemented Interfaces:

MessagingService, Service

public abstract class AbstractMessagingService
extends ServiceDelegator
implements MessagingService

Implementation of the MessagingService interface.

Field Summary

Fields

Modifier and Type	Field and Description
protected MessageQueue	queue
protected CdsRuntime	runtime
protected CdsProperties.Messaging.MessagingServiceConfig	serviceConfig

Fields inherited from interface com.sap.cds.services.messaging.MessagingService

COMPOSITE_NAME

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractMessagingService(CdsProperties.Messaging.MessagingServiceConfig serviceConfig, CdsRuntime runtime)

Method Summary

Modifier and Type	Method and Description
protected boolean	createOrUpdateQueuesAndSubscriptions() Performs the initialization of the messaging service, by initializing the queues and registering the topic subscriptions.
protected abstract void	createQueue(String name, Map<String,String> properties) Request the broker for creating a queue with the specified queue name.
protected abstract void	createQueueSubscription(String queue, String topic) Requests the broker for creating a queue topic subscription.
void	emit(EventContext context)
void	emit(String topic, Map<String,Object> message)
void	emit(String topic, String message)
protected abstract void	emitTopicMessage(String topic, String message) Performs the message emit on the messaging broker.
void	init() Performs the initialization of the messaging service, by initializing the queues and registering the topic subscriptions.
void	on(String[] events, String[] entities, int order, Handler handler)
protected abstract void	registerQueueListener(String queue, MessagingBrokerQueueListener listener) Registers the MessagingBrokerQueueListener implementation to the specified queue of the message broker.
protected abstract void	removeQueue(String name) Request the broker for queue deletion with all its subscriptions.
protected void	sendMessageEvent(TopicMessageEventContext context)
protected String	toFullyQualifiedQueueName(MessageQueue queue) Translates the queue name corresponding the broker queue name specification.
protected String	toFullyQualifiedTopicName(String topic) Translates the given topic definition to the broker environment specific name (in the enterprise messaging this could be extended by the client name space)
protected String	toTopicName(com.sap.cds.reflect.CdsEvent event) Translates the specified CDS event into the broker topic structure.

Methods inherited from class com.sap.cds.services.ServiceDelegator

after, after, before, before, getDelegatedService, getName, on

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.sap.cds.services.Service

after, after, after, after, after, before, before, before, before, before, create, getName, on, on, on, on

Field Detail

serviceConfig

protected final CdsProperties.Messaging.MessagingServiceConfig serviceConfig

runtime

protected final CdsRuntime runtime

queue

protected final MessageQueue queue

Constructor Detail

AbstractMessagingService

protected AbstractMessagingService(CdsProperties.Messaging.MessagingServiceConfig serviceConfig,
                                   CdsRuntime runtime)

Method Detail

init

public void init()

Performs the initialization of the messaging service, by initializing the queues and registering the topic subscriptions.

createOrUpdateQueuesAndSubscriptions

protected boolean createOrUpdateQueuesAndSubscriptions()

Performs the initialization of the messaging service, by initializing the queues and registering the topic subscriptions.

Returns:

true, if the initialization created queues and/or subscriptions

emit

public void emit(EventContext context)

Specified by:

emit in interface Service

Overrides:

emit in class ServiceDelegator

emit

public void emit(String topic,
                 String message)

Specified by:

emit in interface MessagingService

emit

public void emit(String topic,
                 Map<String,Object> message)

Specified by:

emit in interface MessagingService

sendMessageEvent

@HandlerOrder(value=-9900)
protected void sendMessageEvent(TopicMessageEventContext context)

on

public void on(String[] events,
               String[] entities,
               int order,
               Handler handler)

Specified by:

on in interface Service

Overrides:

on in class ServiceDelegator

toTopicName

protected String toTopicName(com.sap.cds.reflect.CdsEvent event)

Translates the specified CDS event into the broker topic structure.

Parameters:

event - CDS declared event

Returns:

broker agnostic topic specification

toFullyQualifiedQueueName

protected String toFullyQualifiedQueueName(MessageQueue queue)

Translates the queue name corresponding the broker queue name specification.

Parameters:

queue - queue specification

Returns:

broker environment specific queue name

toFullyQualifiedTopicName

protected String toFullyQualifiedTopicName(String topic)

Translates the given topic definition to the broker environment specific name (in the enterprise messaging this could be extended by the client name space)

Parameters:

topic - broker specific topic definition

Returns:

the topic name corresponding the broker environment.

removeQueue

protected abstract void removeQueue(String name)
                             throws IOException

Request the broker for queue deletion with all its subscriptions.

Parameters:

name - queue name

Throws:

IOException - In case an error occurs while creating the queue

createQueue

protected abstract void createQueue(String name,
                                    Map<String,String> properties)
                             throws IOException

Request the broker for creating a queue with the specified queue name.

Parameters:

name - queue name

properties - queue configuration properties

Throws:

IOException - In case an error occurs while creating the queue

createQueueSubscription

protected abstract void createQueueSubscription(String queue,
                                                String topic)
                                         throws IOException

Requests the broker for creating a queue topic subscription. The method returnstrue only when the queue topic subscription was successfully created or already available. Otherwise false is returned.

Parameters:

queue - the queue name

topic - the topic the queue should subscribe to

Throws:

IOException - In case an error occurs during the subscription

registerQueueListener

protected abstract void registerQueueListener(String queue,
                                              MessagingBrokerQueueListener listener)
                                       throws IOException

Registers the MessagingBrokerQueueListener implementation to the specified queue of the message broker.

Parameters:

queue - the queue name

listener - implementation of the MessagingBrokerQueueListener interface

Throws:

IOException - In case when any errors occurs while registering the listener to the broker

emitTopicMessage

protected abstract void emitTopicMessage(String topic,
                                         String message)

Performs the message emit on the messaging broker.

Parameters:

topic - the message topic

message - the raw string message