Red Hat Summit Red Hat SummitSuporteConsoleDesenvolvedoresComeçar um testeContato

Este conteúdo não está disponível no idioma selecionado.

6.2. Publish-Subscribe Channel

Overview
Copiar o link

A publish-subscribe channel, shown in Figure 6.2, “Publish Subscribe Channel Pattern”, is a message channel that enables multiple subscribers to consume any given message. This is in contrast with a point-to-point channel. Publish-subscribe channels are frequently used as a means of broadcasting events or notifications to multiple subscribers.

Figure 6.2. Publish Subscribe Channel Pattern

Publish subscribe channel pattern
View larger image
Publish subscribe channel pattern

Components that support publish-subscribe channel
Copiar o link

The following Apache Camel components support the publish-subscribe channel pattern:
  • JMS
  • ActiveMQ
  • XMPP
  • SEDA for working with SEDA in the same CamelContext which can work in pub-sub, but allowing multiple consumers.
  • see VM in the Apache Camel Component Reference Guide as SEDA, but for use within the same JVM.

JMS
Copiar o link

In JMS, a publish-subscribe channel is represented by a topic. For example, you can specify the endpoint URI for a JMS topic called StockQuotes as follows: 
jms:topic:StockQuotes
Copy to Clipboard Toggle word wrap
See Jms in the Apache Camel Component Reference Guide for more details.

ActiveMQ
Copiar o link

In ActiveMQ, a publish-subscribe channel is represented by a topic. For example, you can specify the endpoint URI for an ActiveMQ topic called StockQuotes, as follows: 
activemq:topic:StockQuotes
Copy to Clipboard Toggle word wrap
See ActiveMQ in the Apache Camel Component Reference Guide for more details.

XMPP
Copiar o link

The XMPP (Jabber) component supports the publish-subscribe channel pattern when it is used in the group communication mode. See Xmpp in the Apache Camel Component Reference Guide for more details.

Static subscription lists
Copiar o link

If you prefer, you can also implement publish-subscribe logic within the Apache Camel application itself. A simple approach is to define a static subscription list, where the target endpoints are all explicitly listed at the end of the route. However, this approach is not as flexible as a JMS or ActiveMQ topic.

Java DSL example
Copiar o link

The following Java DSL example shows how to simulate a publish-subscribe channel with a single publisher, seda:a, and three subscribers, seda:b, seda:c, and seda:d: 
from("seda:a").to("seda:b", "seda:c", "seda:d");
Copy to Clipboard Toggle word wrap
Note
This only works for the InOnly message exchange pattern.

XML configuration example
Copiar o link

The following example shows how to configure the same route in XML: 
<camelContext id="buildStaticRecipientList" xmlns="http://camel.apache.org/schema/spring">
  <route>
    <from uri="seda:a"/>
    <to uri="seda:b"/>
    <to uri="seda:c"/>
    <to uri="seda:d"/>
  </route>
</camelContext>
Copy to Clipboard Toggle word wrap
Voltar ao topo
Red Hat logoGithubredditYoutubeTwitter

Aprender

Experimente, compre e venda

Comunidades

Sobre a documentação da Red Hat

Ajudamos os usuários da Red Hat a inovar e atingir seus objetivos com nossos produtos e serviços com conteúdo em que podem confiar. Explore nossas atualizações recentes.

Tornando o open source mais inclusivo

A Red Hat está comprometida em substituir a linguagem problemática em nosso código, documentação e propriedades da web. Para mais detalhes veja o Blog da Red Hat.

Sobre a Red Hat

Fornecemos soluções robustas que facilitam o trabalho das empresas em plataformas e ambientes, desde o data center principal até a borda da rede.

Theme

© 2025 Red Hat