[[Processor-Processor]]
= Processor

The
https://www.javadoc.io/doc/org.apache.camel/camel-api/current/org/apache/camel/Processor.html[Processor]
interface is used to implement consumers of message exchanges or to
implement a xref:{eip-vc}:eips: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:

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

Then in Camel you can do:

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

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 can do:

[source,java]
----
from("activemq:myQueue").process("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. This approach is better if you do not want to use this processor again.
From reusability perspective, it is not recommended to follow this approach.

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

There is a base class called
https://www.javadoc.io/doc/org.apache.camel/camel-support/current/org/apache/camel/support/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
https://www.javadoc.io/doc/org.apache.camel/camel-support/current/org/apache/camel/support/DefaultComponent.html[DefaultComponent]
which returns instances of ProcessorEndpoint. For more details see
xref:writing-components.adoc[Writing Components]

