OGNL
Since Camel 1.1
Camel allows OGNL (Apache Commons OGNL) to be used as an Expression or Predicate in Camel routes.
For example, you can use MVEL in a Predicate with the Content Based Router EIP.
You can use OGNL dot notation to invoke operations. If you for instance
have a body that contains a POJO that has a getFamilyName method then
you can construct the syntax as follows:
request.body.familyNameOr use similar syntax as in Java:
getRequest().getBody().getFamilyName()Variables
| Variable | Type | Description |
|---|---|---|
this |
Exchange |
the Exchange is the root object |
context |
CamelContext |
the CamelContext |
exchange |
Exchange |
the Exchange |
exchangeId |
String |
the exchange id |
exception |
Throwable |
the Exchange exception (if any) |
request |
Message |
the message |
message |
Message |
the message |
headers |
Map |
the message headers |
header(name) |
Object |
the message header by the given name |
header(name, type) |
Type |
the message header by the given name as the given type |
properties |
Map |
the exchange properties |
property(name) |
Object |
the exchange property by the given name |
property(name, type) |
Type |
the exchange property by the given name as the given type |
Example
For example, you could use OGNL inside a Message Filter
from("seda:foo")
.filter().ognl("request.headers.foo == 'bar'")
.to("seda:bar");And in XML:
<route>
<from uri="seda:foo"/>
<filter>
<ognl>request.headers.foo == 'bar'</ognl>
<to uri="seda:bar"/>
</filter>
</route>Loading script from external resource
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",
e.g. to refer to a file on the classpath you can do:
.setHeader("myHeader").ognl("resource:classpath:myognl.txt")Dependencies
To use OGNL in your camel routes you need to add the dependency on camel-ognl which implements the OGNL 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-ognl</artifactId>
<version>x.x.x</version>
</dependency>Spring Boot Auto-Configuration
When using ognl with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-ognl-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>The component supports 2 options, which are listed below.