org.springframework.integration.handler
Class MessageHandlerChain

java.lang.Object
  org.springframework.integration.context.IntegrationObjectSupport
      org.springframework.integration.handler.AbstractMessageHandler
          org.springframework.integration.handler.MessageHandlerChain

All Implemented Interfaces:

BeanFactoryAware, BeanNameAware, InitializingBean, Ordered, NamedComponent, MessageHandler, MessageProducer, TrackableComponent

public class MessageHandlerChain
extends AbstractMessageHandler
implements MessageProducer, Ordered

A composite MessageHandler implementation that invokes a chain of MessageHandler instances in order.

Each of the handlers except for the last one must implement the MessageProducer interface. The last handler must also if the chain itself has an output channel configured. No other assumptions are made about the type of handler.

It is expected that each handler will produce reply messages and send them to its output channel, although this is not enforced. It is possible to filter messages in the middle of the chain, for example using a MessageFilter. A MessageHandler returning null will have the same effect, although this option is less expressive.

This component can be used from the namespace to improve the readability of the configuration by removing channels that can be created implicitly.

 <chain>
     <filter ref="someFilter"/>
     <bean class="SomeMessageHandlerImplementation"/>
     <transformer ref="someTransformer"/>
     <aggregator ... />
 </chain>
 

Author:

Mark Fisher, Iwein Fuld

Field Summary

Fields inherited from class org.springframework.integration.handler.AbstractMessageHandler

logger

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

MessageHandlerChain()

Method Summary

String	getComponentType() Subclasses may implement this method to provide component type information.
int	getOrder()
protected void	handleMessageInternal(Message<?> message)
protected void	onInit() Subclasses may implement this for initialization logic.
void	setHandlers(List<MessageHandler> handlers)
void	setOrder(int order)
void	setOutputChannel(MessageChannel outputChannel) Specify the MessageChannel to which produced Messages should be sent.
void	setSendTimeout(long sendTimeout)

Methods inherited from class org.springframework.integration.handler.AbstractMessageHandler

handleMessage, setShouldTrack

Methods inherited from class org.springframework.integration.context.IntegrationObjectSupport

afterPropertiesSet, getBeanFactory, getComponentName, getConversionService, getRequiredMetadataPersister, getTaskScheduler, setBeanFactory, setBeanName, setComponentName, setConversionService, setTaskScheduler, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.integration.context.NamedComponent

getComponentName

Constructor Detail

MessageHandlerChain

public MessageHandlerChain()

Method Detail

setHandlers

public void setHandlers(List<MessageHandler> handlers)

setOutputChannel

public void setOutputChannel(MessageChannel outputChannel)

Description copied from interface: MessageProducer

Specify the MessageChannel to which produced Messages should be sent.

Specified by:

setOutputChannel in interface MessageProducer

setSendTimeout

public void setSendTimeout(long sendTimeout)

setOrder

public void setOrder(int order)

Overrides:

setOrder in class AbstractMessageHandler

getOrder

public int getOrder()

Specified by:

getOrder in interface Ordered

Overrides:

getOrder in class AbstractMessageHandler

getComponentType

public String getComponentType()

Description copied from class: IntegrationObjectSupport

Subclasses may implement this method to provide component type information.

Specified by:

getComponentType in interface NamedComponent

Overrides:

getComponentType in class AbstractMessageHandler

onInit

protected void onInit()
               throws Exception

Description copied from class: IntegrationObjectSupport

Subclasses may implement this for initialization logic.

Overrides:

onInit in class IntegrationObjectSupport

Throws:

Exception

handleMessageInternal

protected void handleMessageInternal(Message<?> message)
                              throws Exception

Specified by:

handleMessageInternal in class AbstractMessageHandler

Throws:

Exception