Handling application stop event in tomcat based red5 compilations

As you would know red5 is a media server package, which runs on top or other server cores  like Tomcat and Jetty.  There are few minor differences , hence in the way both compilations handle events and behaviors. The one we will be talking about here is specifically the “appStop” event. The “appStop” is suppose to fire off whenever the application stops/shuts down. The anomaly here is that on a tomcat based red5 compilations (which is the default one) the “appStop” does not fire up. This is because the is no straight forward  “hook” / “point of entry” to determine when the server core stops. Hence we need to create a “Shutdown Hook” to handle the server/application shutdown by ourself.

The best way to do this is to create a internal / private class in your Application class source.  Sample:

/* ShutDown Hook for Red5 Application */
class ShutdownHook extends Thread
{
Application app;

public ShutdownHook(Application app)
{
this.app = app;
}

public void run()
{
// do something here
}
}

Next we relate it to our Application class by the “addShutdownHook” method. This method is not something for red5 only. Its the most common way to intercept and handle your java application shutdown. So in the Application class appStart() method we can add:

public boolean appStart(IScope app)
{

Runtime.getRuntime().addShutdownHook(new ShutdownHook(this));

return true;
}

We add it to the appStart() method to make sure it is called only once.
Note how we pass the reference to the Application class itself to the constructor “ShutdownHook”. Now by defining the properties as “protected” or “public” you can access then when the application/server is shutting down and do any cleanup jobs that you may have.

SwfMetaDataInjector – a flash SEO tool

swfmetadatainjector

I have always found it very difficult to understand and build java applications. Hence i always used to run away from the sound of it. But believe it or not now i find, a person who has worked well with flash/flex will find java to be very understandable. You can say flash added a expression to java over the few years.  So anyway to quench my thirst i decided to work on a java GUI application this week. And here it is –  “SwfMetaDataInjector”. Flash has supported metadata even before Google  / Yahoo started indexing swfs wit their  special algorithms. This meta data is stored as a markup, in RDF (Resource Description Framework) format. To know more about this you can read a very intuitive article by Robert Reinhardt

SwfMetaDataInjector lets you write back meta information into swf files even without their fla sources. currently it supports swfs published for flash player 8 and below. i hope to do better with it over time. The application will require you to have the latest java runtime. I this works out forthcoming versions will have batch processing capabilities and better UI. Currently this application is at version 0.01 .

You can download the application here