I am trying to understand what is the correct way of usage JNI from Servlet.
As I understand there are several problems:
- If native DLL crashes, it will bring down whole app server
- If DLL is loaded by one class loaded, than another class loader won't be able to load and use it.
I searched internet and found couple of possible solution
- Create standalone JMS enabled application and use JMS in Servlet to communicate with it.
- Run standalone server, load in it JNI and talk to it through RMI
- Use Java Connector architecture
I would appreciate any information on this subject, what is best practice in this case?
P.S. I am not sure whether it's important, but the application which needs to use native DLL runs on JBoss.
I would absolutely not run a JNI-based tool in a Java EE app server. Your suggestion for using JMS is a good one. You could create a service around message based Beans to respond to messages dispatched by your external service:
http://oreilly.com/catalog/entjbeans3/chapter/ch13.html
Here is the link to the Oracle Java EE documentation on Message-driven beans:
http://download.oracle.com/javaee/5/tutorial/doc/bnbpk.html
I would suggest getting two JBoss servers to talk to one another over JMS is easier than writing a JCA adapter, and that JMS message-driven beans are a cleaner interface. JCA doesn't seem to be evolving at all - there doesn't seem to be any great implementation tutorials (that's just my perception).
