EJB interview questions Part7

17. How to deploy in J2EE (i.e Jar, War file) ?

Each web application should be contained in a war (web archive) file. War files are nothing but a jar file containing atleast one descriptor called web.xml. The file structure of war file is:

/--
|
| WEB-INF
| |
| |-- WEB.XML (Deployment descriptor)
| |-- classes (Folder containing servlets and JSPs
|
| META-INF
| |
| |-- MANIFEST.MF
|
| all utility files and resources like error pages etc.

Each enterprise bean is stored in a jar file. The jar file contains all standard files like manifest and atleast one additional file called ejb-jar.xml. The structure of a jar file is:

/--
|
| META-INF
| |
| |-- MANIFEST.MF
| |-- ejb-jar.xml
|
| all classes as in a normal jar file.

Both jar and war files are placed inside a ear (enterprise archive) file. The structure of an ear file is

/--
|
| META-INF
| |
| |-- MANIFEST.MF
| |-- application.xml
|
| jar and war files.

TODO may be we should add the structure of all the deployment descriptors here as well.

18. Types of transaction ?

19. What is bean managed transaction ?

20. What are transaction attributes ?

21. What is JTS ?

22. What are the Isolation level in JDBC transaction ?

23. What is Connection pooling? Is it advantageous?

24. Method and class used for Connection pooling ?

************************* SERVLET QUESTIONS ************************************

25. What methods do u use in Servlet - Applet communication ?

TODO don't know