Advanced Uses

Bridging Topics

It is possible to 'bridge' data from the Data Feeds platforms to your own ActiveMQ server. You may want to do this if:

• You need to store messages for longer than the durable subscription TTL of 5 minutes
• You want to have multiple consumers connected over a slow network connection

If you do this, please don't simply re-publish data for other people or organisations. Usage of the Data Feeds platforms is monitored, and more users equals better opportunity for making further data available!

Be warned - this example assumes knowledge of ActiveMQ, and is community-supported only.

Configuration

Download ActiveMQ and add the following configuration to conf/activemq.xml before the end of the beans tag:

<import resource="camel.xml"/>

Create the file conf/camel.xml with the following:

<?xml version="1.0"?>
<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-2.0.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd">

  <camelContext xmlns="http://camel.apache.org/schema/spring" id="camel">
  </camelContext>

  <bean id="amq" class="org.apache.activemq.camel.component.ActiveMQComponent">
    <property name="brokerURL" value="tcp://localhost:61616"/>
  </bean>
</beans>

This sets up a Camel Context in which you can configure routes.

To connect to an ActiveMQ service, add the following bean outside the camelContext tag:

  <bean id="$NAME$" class="org.apache.activemq.camel.component.ActiveMQComponent">
    <property name="brokerURL" value="tcp://$HOSTNAME$:$PORT$"/>
    <property name="userName" value="$USERNAME$"/>
    <property name="password" value="$PASSWORD"/>
  </bean>

Replace $NAME$ with the name of the bean, e.g. "darwin" or "networkrail". Replace $HOSTNAME$:$PORT$ with either publicdatafeeds.networkrail.co.uk:61619 or datafeeds.nationalrail.co.uk:61616, and $USERNAME$ and $PASSWORD$ with the username/password as appropriate.

To route data from a queue on the National Rail Enquiries service, add the following within the camelContext tag:

<route>
  <from uri="$NAME$:queue:$QUEUE$"/>
  <to uri="amq:topic:$TOPIC$"/>
</route>

To route data from a topic on the Network Rail service, add the following within the camelContext tag:

<route>
  <from uri="$NAME$:topic:$TOPIC$?clientId=$CLIENT_ID$&amp;durableSubscriptionName=$SUBSCRIPTION_NAME$"/>
  <to uri="amq:topic:$TOPIC$"/>
</route>

Replace $CLIENT_ID$ with a client ID which start with the email address you use to subscribe, followed by the name of the feed e.g. "user@example.com-td" for the TD feed. Set a sensible name for the $SUBSCRIPTION_NAME$ setting, for example, your email address.

Finally, start ActiveMQ, and check the web interface to ensure your data is being routed.