QueTwo's Blog

Ok, lets dive right into a really geeky topic… destinations in BlazeDS and LiveCycle Data Services.

For one of my customers, I was given the requirement to create a runtime destination in BlazeDS.  BlazeDS, along with its bigger brother LiveCycle allow you to create destinations in one of two ways — via the configuration XML files (services-config.xml, and related files), or via Java calls.  I won’t talk about the XML file method because it is extremely well documented.  However, the biggest disadvantage of the XML file method of creating destinations is that you usually have to reload or reboot your server in order for the changes to take affect. 

Runtime Destinations are not permanent — they do not persist during restarts.  They are also not magically added to the XML documents either.  Their creation is also often blocked on shared hosting servers as well.  But besides that, they act and smell just like ones created by the XML documents.  Why would you want to use them?   There are quite a few reasons for wanting them — for example to help secure your server by only exposing your destinations on demand, or by providing private destinations to clients so there is no way that data can be shared (in that case you COULD use subtopics, but that is controlled by the client).  In my case I was asked to provide a solution where the client would not have to change any configuration files when they installed our application.  We were using ColdFusion 9 as our back-end server, but these techniques work for Java based solutions too (you would just have to change the Syntax a bit).

I’ll start off by saying that the documentation is extremely poor (I wish Adobe would make this stuff clearer one day!), but with the help of two people, Sven Ramuschkat and Marko Simic, I was able to get to the point where reading the source code made sense.

The first step in creating the dynamic destination was getting the instance of the Message Broker.  The Message Broker in BlazeDS/LCDS is the guy who does all the work for remoting, messaging, data services and proxying.  You can access it in ColdFusion with the following commands

this.blazeDSClass = createObject("java", "flex.messaging.MessageBroker");
this.blazeDS = this.blazeDSClass.getMessageBroker(javacast("null", ""));

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