JXPath

Since Camel 1.3

Camel supports JXPath to allow XPath expressions to be used on beans in an Expression or Predicate to be used in the DSL or Xml Configuration. For example you could use JXPath to create an Predicate in a Message Filter or as an Expression for a Recipient List.

You can use XPath expressions directly using smart completion in your IDE as follows

from("queue:foo").filter().
  jxpath("/in/body/foo").
  to("queue:bar")

JXPath Options

The JXPath language supports 2 options, which are listed below.

Name Default Java Type Description

lenient

false

Boolean

Allows to turn lenient on the JXPathContext. When turned on this allows the JXPath expression to evaluate against expressions and message bodies which may be invalid / missing data. This option is by default false

trim

true

Boolean

Whether to trim the value to remove leading and trailing whitespaces and line breaks

Spring Boot Auto-Configuration

When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-jxpath-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 3 options, which are listed below.

Name Description Default Type

camel.language.jxpath.enabled

Enable jxpath language

true

Boolean

camel.language.jxpath.lenient

Allows to turn lenient on the JXPathContext. When turned on this allows the JXPath expression to evaluate against expressions and message bodies which may be invalid / missing data. This option is by default false

false

Boolean

camel.language.jxpath.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks

true

Boolean

Variables

Variable Type Description

this

Exchange

the Exchange object

in

Message

the exchange.in message

out

Message

the exchange.out message

Options

Option Type Description

lenient

boolean

Camel 2.11/2.10.5: Allows to turn lenient on the JXPathContext. When turned on this allows the JXPath expression to evaluate against expressions and message bodies which may be invalid / missing data. See more details at the JXPath Documentation This option is by default false.

Using XML configuration

If you prefer to configure your routes in your Spring XML file then you can use JXPath expressions as follows

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd">

  <camelContext id="camel" xmlns="http://activemq.apache.org/camel/schema/spring">
    <route>
      <from uri="activemq:MyQueue"/>
      <filter>
        <jxpath>in/body/name = 'James'</xpath>
        <to uri="mqseries:SomeOtherQueue"/>
      </filter>
    </route>
  </camelContext>
</beans>

Examples

Here is a simple example using a JXPath expression as a predicate in a Message Filter

JXPath injection

You can use Bean Integration to invoke a method on a bean and use various languages such as JXPath to extract a value from the message and bind it to a method parameter.

For example

public class Foo {

    @MessageDriven(uri = "activemq:my.queue")
    public void doSomething(@JXPath("in/body/foo") String correlationID, @Body String body) {
        // process the inbound message here
    }
}

Loading script from external resource

Since Camel 2.11

You can externalize the script and have Camel load it from a resource such as "classpath:", "file:", or "http:".

 This is done using the following syntax: `"resource:scheme:location"`,
eg to refer to a file on the classpath you can do:
.setHeader("myHeader").jxpath("resource:classpath:myjxpath.txt")

Dependencies

To use JXpath in your camel routes you need to add the a dependency on camel-jxpath which implements the JXpath language.

If you use maven you could just add the following to your pom.xml, substituting the version number for the latest & greatest release (see the download page for the latest versions).

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-jxpath</artifactId>
  <version>x.x.x</version>
</dependency>

Otherwise, you’ll also need Commons JXPath.

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