Getting automatic updates from database

Hi,

Not sure if this is the correct place to post this, but here goes, please let me know if there is a better place for questions like this.

I currently have a servlet based server using http comm's to a flash movie client, everything is currently working fine, I now need to push data from an oracle database to the client.

I have 2 questions:

1:

Using Oracle, does anyone know the best way to get Oracle to let me know in the Java of a data change? Triggers? I am currently only using Servlets and would like to keep it as simple as possible, only using EJB's etc... if it's the only way.

2:

I have looked into 2 ways of pushing this data to the flash client, one is the standard socket architecture, this is fairly standard and easy to implement and understand, but it needs a port to be open for this comm's, in an internet situation this might be a problem. The other idea is to use a ServletAdapter and keep the http connection from the Flash to the a Servlet open pushing data to the client as needed. Does anyone have any opinions on these 2 ideas?

Any help/discussion on these 2 questions would be greatly appreciated.

Thanks in advance.

Phil Maskell

1. Not unless you are using JServer (and so running you Java application in Oracle). JDBC is inherently pull in design - so there is no way to use it with a push based architecture.

2. "ServletAdapter"? Not sure what you mean by this. But:

keep the http connection from the Flash to the a Servlet open pushing data to the client as needed

This isn't how HTTP works. You have the same problem with it, and therefore HTTPServlets: they are inherently pull, not push. A servlet is not going to be able to update anything client side (like a Flash object) without a request. What you need (as you've realised) is possibly some sort of client side code which opens a socket to a serverside component which possible polls the DB for changes. I've no idea if your Flash components can do this (I've never had any use for Flash) - you suggest its not a problem so I'll take your word for it.