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I need advice as to the best way to implement database access from a Swing Rich Client app to a remote MySQL database using Hibernate and a DAO Factory Structure.

The MySQL database will be running behind a firewall, so I was thinking that straight JDBC access from the Swing app would not be wise. One option I was considering was using JMX, exposing the DAO functions from an MBean which would run on a box behind the same firewall where the database server resides. Using basic RMI calls, this should work fairly well. But is it necessary?

Any recommendations?

Thanks!

M

I do not think that exposing your mysql database to the internet is wise, even if using https as a transport.

A middle layer has lots of advantages including some very basic ones like:

1. enforce login using user scheme that is not dependent on mysql and you can define privileges that make sense to your application
2. caching
3. database data modified in consistent way
4. very likely less chatty protocol
5. ability to add more mid tier servers if some of the API becomes CPU bound
6. ability to add more database servers (possibly read-only) if one server cannot take the load

There are multiple possibilities to do remoting, Spring's capabilities are pretty nice and you can use some of the third party libraries standalone. Those are pretty light in terms of configuration and usage.

http://www.springframework.org/docs/ref ... oting.html

You can also define your own XML, json or go for some of the heavier stuff SOAP and so on ... lots of good stuff out there.


Marius

Thanks Marius. I was actually considering Spring also and will take a look at the link you mentioned. What do you think about JMX as a solution?

Mark

Mark,

I think JMX is great for management/monitoring ... where would you use this in your application? All the way to the Swing client? This seems appropriate if the application is mostly a monitoring application, but I do not know if it's worth using as a general communication protocol.

In my experience remoting itself is not as big of an issue as selecting API with the proper granularity given the bandwidth, client hardware, transaction requirements and other.

It's hard to give good advice, even more so if not enough details are known :)

Good luck,

Marius

Marius:

A friend and I recently had a discussion regarding remote access from a Rich Client app, Swing in this case, and JMX came up as a viable solution. Based on my experience w/JBoss, which is basically just a big MBean server, the JMX approach seemed worth investigating.

However, I have not found any references to anyone using JMX outside of the Management context. So, based on your suggestion, I did a little research into a Spring solution and believe that the Http invoker remoting solution shows promise.

In my situation, it seems unlikely that the majority of the customers using the Swing client to access a database behind their firewall would be willing to open up the necessary ports to allow RMI access, so it looks like the Http invoker approach seems like a good idea. It was suggested to me that a direct JDBC connection to, in this case, a MySQL instance at, say, port 3306, may be acceptable based on the use of someting like IpSEC to provide security. But I find it hard to believe that any fortune 100 company would allow this. That is why I am pushing the web services approach, i.e. Http invoker.

I usually don't develop systems where Rich Clients access central databases in this manner. Usually it is in the form of a Web/J2EE app. Any suggestions or experience you have would be appreciated.

Regards,

Mark

Mark,

All your experience from J2EE applies in this scenario to. You still have a web/j2ee server. It's just that instead of displaying information in html,xml,pdf format you are sending objects to a custom (and probably more complex) browser. One plus is that you can and should have stateless interactions between the rich client and the web server, this will allow you to scale.

Good luck :)

Marius

Actually, a web/j2ee component on the server is not a requirement. However, w/Spring Remoting, whether I use Hessian/Burlap or Http Invoker, I was thinking that setting up a Tomcat or Resin server, or even Jetty, and deal with it that way.

Another option presented was using RDBMS specific SSL/SSH wrappers around the connection. MySQL, for instance, has built in yaSSL in v.5.0.10 and above, but I am not sure this would work using Hibernate. And, again, would exposing the db directly to the internet, SSL/SSH included, be more practical or secure than the Spring Remoting implementation? I would say no.

Mark