Content Filter

Camel supports the Content Filter from the EIP patterns using one of the following mechanisms in the routing logic to transform content from the inbound message.

Using a Message Translator
Invoking a Bean with the filtering programmed in Java
Using a Processor with the filtering programmed in Java
Using an Expression

Message Content filtering using a Processor

In this example we add our own Processor using explicit Java to filter the message:

from("direct:start")
    .process(new Processor() {
        public void process(Exchange exchange) {
            String body = exchange.getMessage().getBody(String.class);
            // do something with the body
            // and replace it back
            exchange.getMessage().setBody(body);
        }
    })
    .to("mock:result");

Message Content filtering using a Bean EIP

we can use Bean EIP to use any Java method on any bean to act as content filter:

from("activemq:My.Queue")
    .bean("myBeanName", "doFilter")
    .to("activemq:Another.Queue");

And in XML DSL:

<route>
    <from uri="activemq:Input"/>
    <bean ref="myBeanName" method="doFilter"/>
    <to uri="activemq:Output"/>
</route>

Message Content filtering using expression

Some languages like XPath, and XQuery can be used to transform and filter content from messages.

In the example we use xpath to filter a XML message to select all the <foo><bar> elements:

from("activemq:Input")
  .setBody().xpath("//foo:bar")
  .to("activemq:Output");

And in XML DSL:

<route>
  <from uri="activemq:Input"/>
  <setBody><xpath>//foo:bar</xpath></setBody>
  <to uri="activemq:Output"/>
</route>