The validate pattern provides a convenient syntax to check whether the content of a message is valid. The validate DSL command takes a predicate expression as its sole argument: if the predicate evaluates to true, the route continues processing normally; if the predicate evaluates to false, a PredicateValidationException is thrown.

The following route validates the body of the current message using a regular expression:

from("jms:queue:incoming")
  .validate(body(String.class).regex("^\\w{10}\\,\\d{2}\\,\\w{24}$"))
  .to("bean:MyServiceBean.processLine");

You can also validate a message header—for example:

from("jms:queue:incoming")
  .validate(header("bar").isGreaterThan(100))
  .to("bean:MyServiceBean.processLine");

And you can use validate with the simple expression language:

from("jms:queue:incoming")
  .validate(simple("${in.header.bar} == 100"))
  .to("bean:MyServiceBean.processLine");

To use validate in the XML DSL, the recommended approach is to use the simple expression language:

<route>
  <from uri="jms:queue:incoming"/>
  <validate>
    <simple>${body} regex ^\\w{10}\\,\\d{2}\\,\\w{24}$</simple>
  </validate>
  <beanRef ref="myServiceBean" method="processLine"/>
</route>

<bean id="myServiceBean" class="com.mycompany.MyServiceBean"/>

You can also validate a message header—for example:

<route>
  <from uri="jms:queue:incoming"/>
  <validate>
    <simple>${in.header.bar} == 100</simple>
  </validate>
  <beanRef ref="myServiceBean" method="processLine"/>
</route>

<bean id="myServiceBean" class="com.mycompany.MyServiceBean"/>