# MQTT Interceptor Example

    To run the example, simply type mvn verify from this directory,
    or mvn -PnoServer verify if you want to start and create the server manually.

This example shows you how to implement and configure a simple incoming, server-side MQTT interceptor with ActiveMQ Artemis.

ActiveMQ Artemis allows an application to use an interceptor to hook into the messaging system. All that needs to do is to implement the Interceptor interface, as defined below:

             public interface Interceptor
             {
                boolean intercept(final MqttMessage mqttMessage, RemotingConnection connection);
             }

Once you have your own interceptor class, add it to the broker.xml, as follows:

            <configuration>
            ...
               <remoting-incoming-interceptors>
                  <class-name>org.apache.activemq.artemis.mqtt.example.SimpleMQTTInterceptor</class-name>
               </remoting-incoming-interceptors>
            ...
            </configuration>

With interceptor, you can handle various events in message processing. In this example, a simple interceptor, SimpleMQTTInterceptor, is implemented and configured. When the example is running, the interceptor will modify the payload of a sample MQTT message.

With our interceptor we always return `true` from the `intercept` method. If we were to return `false` that signifies that no more interceptors are to run. Throw an exception to abort processing of the packet.