WAS / WSAD / RAD - Interview Questions and Answers

1. What is deployment descriptor ?

Ans. Deployment descriptor is an XML file that describes how to deploy a module or application by specifying configuration and container options. For example, an EJB deployment descriptor passes information to an EJB container about how to manage and control an enterprise bean. 

2. Which file is used as deployment descriptor in your application ?

Ans. web.xml

3. Difference between web and application server ?


Webserver takes care of http request and then pass the request if required to application server. Webserver keep tracks of the requesting client , may render the complete page / media from the cache or its repository. 

Application server holds the applicatiton logic, communication with DB , services etc. 

4. Is WAS a web server or Application server ?

Ans. Its both application as well as web server.

5. What is the relation between WAS and Eclipse ?

Ans. WSAD is an IDE thats built using Eclipse technology.

6. What is the difference between JAR , WAR and EAR ?


JAR only contains compiles Java files or classes.
WAR contains servlet class files and the web components ( html , JSP , CSS , Media )
EAR contains all of the above.

7. How to add an External Jar to the project ?

Ans. Right click the project and click properties-> Java build path -> Libraries tab -> Add External Jar.

8. How to change the default class file folder for the project ?

Ans. Right click the project and click properties -> Java build path -> Source Tab -> Browse and set the Default Output folder.

9. How to disable XML validation ?

Ans.  Right click the project and click properties -> Validation -> uncheck XML and XML Schema Validator.

10. How to change the workspace JDK compiler compliance level ?

Ans. Access Windows -> Preferences -> Compliance and Class Files 

Change Compiler Compliance level

11. What is JDBC ?

Ans.  JDBC technology is an API (included in both J2SE and J2EE releases) that provides cross-DBMS connectivity to a wide range of SQL databases and access to other tabular data sources, such as spreadsheets or flat files.

12. What is EJB ?

Ans. EJB or Enterprise Java Beans is the server-side component architecture for the Java 2 Platform, Enterprise Edition (J2EE) platform. EJB technology enables rapid and simplified development of distributed, transactional, secure and portable applications based on Java technology.

13. What is the purpose of changing the compiler compliance level ?

Ans. Application may have code or JARs that work good with earlier version of Java but not the latest version. In such case we may have to use earlier compiler version to build it.

14. What is the role of .metadata file ?

Ans. .metadata holds the project references in workspace. Its an important file that bind the imported projects.

15. How to set the target runtime for the project ?


1. Right click the project, and then select Properties.

2. Click Server in the left navigation in the properties window.

3. Select the target runtime.

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