Configure JNDI for BlazeDS

Question

Hi everybody, I'm having some problems.
Actualy I have a Flex project, configured with BlazeDS that will work as a dashboard for a system.
The system is a java web project that need send messages to the dashboard.
The main idea is to configure blazeDS in a server and run the java web aplication and the flex dashboard in another one.
How could I configure flex application and java web application to consume and produce messages using the blazeDS that is hosted in another server?
Some people told me that I need to use JNDI but I didn´t understand very well. Could anybody help to config the tomcat´s context.xml file and the configurations flex file from flex application and java web application?
Thanks,
Paulo Fabiano Langer

Answer 1

>>How could I configure flex application and java web application to consume and produce messages using the blazeDS that is hosted in another server?
Configuring a Flex application to use BlazeDS when the Flex application and BlazeDS are hosted on different servers is pretty easy. You just need to make sure when you compile your Flex application that the services-config.xml file that you compile against contains all the correct information to connect to the BlazeDS server. For example if you have a channel definition in your services-config.xml file that uses tokens you would need to replace the tokens with hardcoded values that pointed to your BlazeDS server.
<channel-definition id="my-amf" class="mx.messaging.channels.AMFChannel">
    <endpoint url="http://{server.name}:{server.port}/{context.root}/messagebroker/amf" class="flex.messaging.endpoints.AMFEndpoint"/>
    <properties>
        <polling-enabled>false</polling-enabled>
     </properties>
</channel-definition>
If you plan on deploying your Flex application on ServerA but BlazeDS is running on ServerB the above code won't work because {server.name} will be replaced at runtime by ServerA because this is where the Flex application will be loaded from. You'd need to replace {server.name} with ServerB so that when the Flex application got loaded from ServerA it would know to connect to the BlazeDS server at ServerB.
Also, when deploying your Flex application and BlazeDS on separate servers you will need a cross-domain.xml file on the BlazeDS server to allow the Flex application to communicate with it. This is because of the way that security works in the Flash player. For more information on security in the Flash player and cross-domain.xml files take a look at the following chapter in the Programming ActionScript 3.0 guide.
http://livedocs.adobe.com/flex/2/docs/wwhelp/wwhimpl/js/html/wwhelp.htm?href=00001950.html
If you want your Flex application and your Java web application to both produce and consume messages using BlazeDS you are going to need to use JMS. The following article on using BlazeDS and JMS should help you.
http://www.joshuaostrom.com/2008/08/01/tunkey-blazeds-jms-activemq/
Basically, your Flex application would send a message to a JMS messaging destination in BlazeDS. BlazeDS would send this message into the JMS messaging system. Your Java application would be subscribed to the same JMS topic/queue that BlazeDS was configured to use and so would receive the message the Flex application sent to BlazeDS. Sending messages from the Java application to be received by the Flex application would basically work the same way in reverse.
Hope that helps.
-Alex