Red Hat Summit Red Hat SummitSupportoConsoleSviluppatoriInizia una provaContatti

Questo contenuto non è disponibile nella lingua selezionata.

8.12. Composed Message Processor

Composed Message Processor
Copia collegamento

The composed message processor pattern, as shown in Figure 8.11, “Composed Message Processor Pattern”, allows you to process a composite message by splitting it up, routing the sub-messages to appropriate destinations, and then re-aggregating the responses back into a single message.

Figure 8.11. Composed Message Processor Pattern

Composed Message Processor Pattern
View larger image
Composed Message Processor Pattern

Java DSL example
Copia collegamento

The following example checks that a multipart order can be filled, where each part of the order requires a check to be made at a different inventory: 
// split up the order so individual OrderItems can be validated by the appropriate bean
from("direct:start")
    .split().body()
    .choice() 
        .when().method("orderItemHelper", "isWidget")
            .to("bean:widgetInventory")
        .otherwise()
            .to("bean:gadgetInventory")
    .end()
    .to("seda:aggregate");

// collect and re-assemble the validated OrderItems into an order again
from("seda:aggregate")
    .aggregate(new MyOrderAggregationStrategy())
    .header("orderId")
    .completionTimeout(1000L)
    .to("mock:result");
Copy to Clipboard Toggle word wrap

XML DSL example
Copia collegamento

The preceding route can also be written in XML DSL, as follows: 
 <route>
   <from uri="direct:start"/>
   <split>
     <simple>body</simple>
     <choice>
       <when>
         <method bean="orderItemHelper" method="isWidget"/>
 	<to uri="bean:widgetInventory"/>
       </when>
       <otherwise>
 	<to uri="bean:gadgetInventory"/>
       </otherwise>
     </choice>
     <to uri="seda:aggregate"/>
   </split>
 </route>
 
 <route>
   <from uri="seda:aggregate"/>
   <aggregate strategyRef="myOrderAggregatorStrategy" completionTimeout="1000">
     <correlationExpression>
       <simple>header.orderId</simple>
     </correlationExpression>
     <to uri="mock:result"/>
   </aggregate>
 </route>
Copy to Clipboard Toggle word wrap

Processing steps
Copia collegamento

Processing starts by splitting the order, using a Splitter. The Splitter then sends individual OrderItems to a Content Based Router, which routes messages based on the item type. Widget items get sent for checking in the widgetInventory bean and gadget items get sent to the gadgetInventory bean. Once these OrderItems have been validated by the appropriate bean, they are sent on to the Aggregator which collects and re-assembles the validated OrderItems into an order again.
Each received order has a header containing an order ID. We make use of the order ID during the aggregation step: the .header("orderId") qualifier on the aggregate() DSL command instructs the aggregator to use the header with the key, orderId, as the correlation expression.
For full details, check the example source here:
Torna in cima
Red Hat logoGithubredditYoutubeTwitter

Formazione

Prova, acquista e vendi

Community

Informazioni sulla documentazione di Red Hat

Aiutiamo gli utenti Red Hat a innovarsi e raggiungere i propri obiettivi con i nostri prodotti e servizi grazie a contenuti di cui possono fidarsi. Esplora i nostri ultimi aggiornamenti.

Rendiamo l’open source più inclusivo

Red Hat si impegna a sostituire il linguaggio problematico nel codice, nella documentazione e nelle proprietà web. Per maggiori dettagli, visita il Blog di Red Hat.

Informazioni su Red Hat

Forniamo soluzioni consolidate che rendono più semplice per le aziende lavorare su piattaforme e ambienti diversi, dal datacenter centrale all'edge della rete.

Theme

© 2025 Red Hat