Oracle/Java application, recommended architectures_问答_开发者

I am working on a desktop Java application that is supposed to connect to an Oracle database via a proxy which can be a Servlet or an EJB or something else that you can suggest.

My question is that what archit开发者_运维百科ecture should be used?

Simple Servlets as proxy between client and database, that connects to the database and sends results back to the client.
An enterprise application with EJBs and remote interfaces to access the database
Any other options that I haven't thought of.

Thanks

Depending on how scalable you want the solution to be, you can make a choice.

EJB (3) can make a good choice but then you need a full blown app server.
You can connect directly using jdbc but that will expose url of db (expose as in every client desktop app will make a connection to the DB. you can not pool, and lose lot of flexibilities). I would not recommend going this path unless your app is really a simple one.
You can create a servlet to act as proxy but its tedious and not as scalable. You will have to write lot of code at both ends
What i would recommend is creating a REST based service that performs desired operations on the DB and consume this in your desktop app.

Start off simple. I would begin with a simple servlet/JDBC-based solution and get the system working end-to-end. From that point, consider:

do you want to make use of conenction pooling (most likely). Consider C3P0 / Apache DBCP
do you want to embrace a framework like Spring ? You can migrate to this gradually, and start with using the servlet MVC capabilities, IoC etc. and use more complex solutions as you require
Do you want to use an ORM ? Do you have complex object graphs that you're persisting/querying, and will an ORM simplify your development ?

If you do decide to take this approach, make sure your architecture is well-layered, so you can swap out (say) raw JDBC in favour of an ORM, and that your development is test-driven, such that you have sufficient test cases to confirm that your solution works whilst you're performing the above migrations.

Note that you may never finalise on a solution. As your requirements change, and your application scales, you'll likely want to swap in/out the technology most suitable for your current requirements. Consequently the architecture of your app is more important than the particular toolset that you choose.

Direct usage of JDBC through some ORM (Hibernate for example) ?

If you're developing a stand-alone application, better keep it simple. In order to use ORM or other frameworks you don't need a J2EE App Server (and all the complexity it takes with it).

If you need to exchange huge amounts of data between the DB and the application, just forget about EJBs, Servlets and Web Services, and just go with Hibernate (or directly with plain old JDBC).

A REST based Web Services solution may be good, as long as you don't have complex data, and high numbers (try to profile how long does it takes to actually unmarshal SOAP messages back and to java objects).

I have had a great deal of success with using Spring-remoting and a servlet based approach. This is a great setup for development as well, since you can easily test your code without deploying to an web container.

You start by defining a service interface to retrieve/store your data (POJO's).
Create the implementation, which can use ORM, straight JDBC or some pooling library (container provided or 3rd party). This is irrelevant to the remote deployment.
Develop your application which uses this service directly (no deployment to a server).
When you are satisfied with everything, wrap your implementation in a war and deploy with the Spring DispatcherServlet. If you use maven, it can be done via the war plugin
Configure the desktop to use the service via Spring remoting.

I have found the ability to easily develop the code by running the service as part of the application to be a huge advantage over developing/debugging something running on a server. I have used this approach both with and without an EJB, although the EJB was still accessed via the servlet in our particular case. Only service to service calls used the EJB directly (also using Spring remoting).