docs/user-manual/modules/ROOT/pages/processor.adoc

[[Processor-Processor]]
= Processor

The
http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/Processor.html[Processor]
interface is used to implement consumers of message exchanges or to
implement a xref:message-translator.adoc[Message Translator].

[[Processor-Usingaprocessorinaroute]]
== Using a processor in a route

Once you have written a class which implements processor like this...

[source,java]
----
public class MyProcessor implements Processor {
    public void process(Exchange exchange) throws Exception {
        // do something...
    }
}
----

You can then easily use this inside a route by declaring the bean in
Spring, say via the XML (or registering it in JNDI if that is your
xref:registry.adoc[Registry]):

[source,xml]
----
<bean id="myProcessor" class="com.acme.MyProcessor"/>
----

Then in Camel you can do:

[source,java]
----
from("activemq:myQueue").to("myProcessor");
----

[[Processor-UsingtheprocessDSL]]
=== Using the process DSL

In your route you can also use the `process` DSL syntax for invoking a
processor.

[source,java]
----
Processor myProcessor = new MyProcessor();
...
from("activemq:myQueue").process(myProcessor);
----

If you need to lookup the processor in the xref:registry.adoc[Registry]
then you should use the `processRef` DSL:

[source,java]
----
from("activemq:myQueue").processRef("myProcessor");
----

[[Processor-Whyuseprocesswhenyoucanusetoinstead]]
== Why use process when you can use to instead?

The process can be used in routes as an anonymous inner class such:

[source,java]
----
    from("activemq:myQueue").process(new Processor() {
        public void process(Exchange exchange) throws Exception {
            String payload = exchange.getIn().getBody(String.class);
            // do something with the payload and/or exchange here
           exchange.getIn().setBody("Changed body");
       }
    }).to("activemq:myOtherQueue");
----

This is usable for quickly whirling up some code. If the code in the
inner class gets a bit more complicated it is of course advised to
refactor it into a separate class.

[[Processor-TurningyourprocessorintoafullComponent]]
== Turning your processor into a full Component

There is a base class called
http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/impl/ProcessorEndpoint.html[ProcessorEndpoint]
which supports the full xref:endpoint.adoc[Endpoint] semantics given a
Processor instance.

So you just need to create a xref:component.adoc[Component] class by
deriving from
http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/impl/DefaultComponent.html[DefaultComponent]
which returns instances of ProcessorEndpoint. For more details see
xref:writing-components.adoc[Writing Components]