org.springframework.cloud.stream.binder

Class AbstractMessageChannelBinder<C extends ConsumerProperties,P extends ProducerProperties,PP extends ProvisioningProvider<C,P>>

java.lang.Object

org.springframework.cloud.stream.binder.AbstractBinder<org.springframework.messaging.MessageChannel,C,P>

org.springframework.cloud.stream.binder.AbstractMessageChannelBinder<C,P,PP>

Type Parameters:

C - the consumer properties type

P - the producer properties type

All Implemented Interfaces:

org.springframework.beans.factory.Aware, org.springframework.beans.factory.InitializingBean, Binder<org.springframework.messaging.MessageChannel,C,P>, org.springframework.context.ApplicationContextAware

Direct Known Subclasses:

KafkaMessageChannelBinder, RabbitMessageChannelBinder

public abstract class AbstractMessageChannelBinder<C extends ConsumerProperties,P extends ProducerProperties,PP extends ProvisioningProvider<C,P>>
extends AbstractBinder<org.springframework.messaging.MessageChannel,C,P>

AbstractBinder that serves as base class for MessageChannel binders. Implementors must implement the following methods:

• createProducerMessageHandler(ProducerDestination, ProducerProperties)
• createConsumerEndpoint(ConsumerDestination, String, ConsumerProperties)

Since:

1.1

Author:

Marius Bogoevici, Ilayaperumal Gopinathan, Soby Chacko

Nested Class Summary

Nested classes/interfaces inherited from class org.springframework.cloud.stream.binder.AbstractBinder

AbstractBinder.JavaClassMimeTypeConversion

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.springframework.expression.ExpressionParser	EXPRESSION_PARSER
protected PP	provisioningProvider ProvisioningProvider delegated by the downstream binder implementations.

Fields inherited from class org.springframework.cloud.stream.binder.AbstractBinder

logger

Constructor Summary

Constructors

Constructor and Description
AbstractMessageChannelBinder(boolean supportsHeadersNatively, String[] headersToEmbed, PP provisioningProvider)

Method Summary

Modifier and Type	Method and Description
protected void	afterUnbindConsumer(ConsumerDestination destination, String group, C consumerProperties) Invoked after the unbinding of a consumer.
protected void	afterUnbindProducer(ProducerDestination destination, P producerProperties) Invoked after the unbinding of a producer.
protected abstract org.springframework.integration.core.MessageProducer	createConsumerEndpoint(ConsumerDestination destination, String group, C properties) Creates MessageProducer that receives data from the consumer destination.
protected abstract org.springframework.messaging.MessageHandler	createProducerMessageHandler(ProducerDestination destination, P producerProperties) Creates a MessageHandler with the ability to send data to the target middleware.
Binding<org.springframework.messaging.MessageChannel>	doBindConsumer(String name, String group, org.springframework.messaging.MessageChannel inputChannel, C properties) Binds an inbound channel to a given destination.
Binding<org.springframework.messaging.MessageChannel>	doBindProducer(String destination, org.springframework.messaging.MessageChannel outputChannel, P producerProperties) Binds an outbound channel to a given destination.

Methods inherited from class org.springframework.cloud.stream.binder.AbstractBinder

afterPropertiesSet, applyPrefix, bindConsumer, bindProducer, buildPartitionRoutingExpression, buildRetryTemplate, constructDLQName, deserializePayloadIfNecessary, deserializePayloadIfNecessary, getApplicationContext, getBeanFactory, groupedName, onInit, serializePayloadIfNecessary, serializePayloadIfNecessary, setApplicationContext, setCodec, setIntegrationEvaluationContext

Methods inherited from class java.lang.Object

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

Field Detail

EXPRESSION_PARSER

protected static final org.springframework.expression.ExpressionParser EXPRESSION_PARSER

provisioningProvider

protected final PP extends ProvisioningProvider<C,P> provisioningProvider

ProvisioningProvider delegated by the downstream binder implementations.

Constructor Detail

AbstractMessageChannelBinder

public AbstractMessageChannelBinder(boolean supportsHeadersNatively,
                                    String[] headersToEmbed,
                                    PP provisioningProvider)

Method Detail

doBindProducer

public final Binding<org.springframework.messaging.MessageChannel> doBindProducer(String destination,
                                                                                  org.springframework.messaging.MessageChannel outputChannel,
                                                                                  P producerProperties)
                                                                           throws BinderException

Binds an outbound channel to a given destination. The implementation delegates to ProvisioningProvider.provisionProducerDestination(String, ProducerProperties) and createProducerMessageHandler(ProducerDestination, ProducerProperties) for handling the middleware specific logic. If the returned producer message handler is an InitializingBean then InitializingBean.afterPropertiesSet() will be called on it. Similarly, if the returned producer message handler e ndpoint is a Lifecycle, then Lifecycle.start() will be called on it.

Specified by:

doBindProducer in class AbstractBinder<org.springframework.messaging.MessageChannel,C extends ConsumerProperties,P extends ProducerProperties>

Parameters:

destination - the name of the destination

outputChannel - the channel to be bound

producerProperties - the ProducerProperties of the binding

Returns:

the Binding for the channel

Throws:

BinderException - on internal errors during binding

createProducerMessageHandler

protected abstract org.springframework.messaging.MessageHandler createProducerMessageHandler(ProducerDestination destination,
                                                                                             P producerProperties)
                                                                                      throws Exception

Creates a MessageHandler with the ability to send data to the target middleware. If the returned instance is also a Lifecycle, it will be stopped automatically by the binder.

In order to be fully compliant, the MessageHandler of the binder must observe the following headers:

• BinderHeaders.PARTITION_HEADER - indicates the target partition where the message must be sent

Parameters:

destination - the name of the target destination

producerProperties - the producer properties

Returns:

the message handler for sending data to the target middleware

Throws:

Exception

afterUnbindProducer

protected void afterUnbindProducer(ProducerDestination destination,
                                   P producerProperties)

Invoked after the unbinding of a producer. Subclasses may override this to provide their own logic for dealing with unbinding.

Parameters:

destination - the bound destination

producerProperties - the producer properties

doBindConsumer

public final Binding<org.springframework.messaging.MessageChannel> doBindConsumer(String name,
                                                                                  String group,
                                                                                  org.springframework.messaging.MessageChannel inputChannel,
                                                                                  C properties)
                                                                           throws BinderException

Binds an inbound channel to a given destination. The implementation delegates to ProvisioningProvider.provisionConsumerDestination(String, String, ConsumerProperties) and createConsumerEndpoint(ConsumerDestination, String, ConsumerProperties) for handling middleware-specific logic. If the returned consumer endpoint is an InitializingBean then InitializingBean.afterPropertiesSet() will be called on it. Similarly, if the returned consumer endpoint is a Lifecycle, then Lifecycle.start() will be called on it.

Specified by:

doBindConsumer in class AbstractBinder<org.springframework.messaging.MessageChannel,C extends ConsumerProperties,P extends ProducerProperties>

Parameters:

name - the name of the destination

group - the consumer group

inputChannel - the channel to be bound

properties - the ConsumerProperties of the binding

Returns:

the Binding for the channel

Throws:

BinderException - on internal errors during binding

createConsumerEndpoint

protected abstract org.springframework.integration.core.MessageProducer createConsumerEndpoint(ConsumerDestination destination,
                                                                                               String group,
                                                                                               C properties)
                                                                                        throws Exception

Creates MessageProducer that receives data from the consumer destination. will be started and stopped by the binder.

Parameters:

group - the consumer group

destination - reference to the consumer destination

properties - the consumer properties

Returns:

the consumer endpoint.

Throws:

Exception

afterUnbindConsumer

protected void afterUnbindConsumer(ConsumerDestination destination,
                                   String group,
                                   C consumerProperties)

Invoked after the unbinding of a consumer. The binder implementation can override this method to provide their own logic (e.g. for cleaning up destinations).

Parameters:

destination - the consumer destination

group - the consumer group

consumerProperties - the consumer properties