jar文件位置-耳文件或服务器lib文件夹？

Question

When deploying an application to JBoss server, for a JAR like ojdbc14.jar (Oracle JDBC), is it better to include this jar in the ear file of the deployment, or should it be deployed to JBoss's server/default/lib folder?

The argument I've been given is that the application needs to support global transactions, hence the datasource must be defined at the application server level (eg copied to server/default/lib folder) so it can talk to other app servers, and for that to happen you need the drivers at the app server level.

I'd like to hear what is the correct approach here. Thanks.

Answer 1

I believe this is the correct approach.

You will typically define your datasource outside of your application (outside of your EAR/WAR) using the appropriate configuration files depending upon the application server you are using. Whereas on JBoss, you usually add your configuration to XML files, with WebLogic, you can create a datasource directly using the Admin console.

Given that this datasource will be created on server startup, the necessary libraries (in your case, ojdbc14.jar) must be available on the classpath of the application server.

I have also come across licensing issues where the use of a 3rd party library prevents you from bundling it within your application.

Also, defining your datasource outside of your application means you do not have to perform a rebuild when the datasource configuration needs to change.

Answer 2

So many time I have done that...

I will always put the jar inside the server/default/lib folder if it has something to have about JDBC.

Because your database driver is loaded one time as soon as the server is started, and not each time you deploy/undeploy the webapplication your are working on.

Your datasources will be availiable for any others sub-projects too, and it will be a great advantage when you have a specific project for integration testing purpose.