Validate - 6.3

Talend ESB Mediation Developer Guide

EnrichVersion
6.3
EnrichProdName
Talend Data Fabric
Talend Data Services Platform
Talend ESB
Talend MDM Platform
Talend Open Studio for ESB
Talend Real-Time Big Data Platform
task
Design and Development
EnrichPlatform
Talend ESB

Validate uses an expression or predicates to validate the contents of a message. It is useful for ensuring that messages are valid before attempting to process them.

You can use the validate DSL with all kind of Predicates and Expressions. Validate evaluates the Predicate/Expression and if it is false a PredicateValidationException is thrown. If it is true message processing continues.

Using from Java DSL

The route below will read the file contents and validate them against a regular expression.

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

Validate is not limited to the message body. You can also validate the message header.

from("file://inbox")
  .validate(header("bar").isGreaterThan(100))
.to("bean:MyServiceBean.processLine");

You can also use validate together with simple.

from("file://inbox")
  .validate(simple("${in.header.bar} == 100"))
.to("bean:MyServiceBean.processLine");

Using from Spring DSL

To use validate in the Spring DSL, the easiest way is to use simple expressions.

<route>
  <from uri="file://inbox"/>
  <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"/>

The XML DSL to validate the message header would looks like this:

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

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