Friends

please try to answer the following questions.
1.what are design patterns? How are they applicable to java
programming?
2.What is custom tag in JSP? give an example on how to build a custom tag using tag library?
3.Have you done any performance tuning in your last project? state them.
4.Can a method be declared as both final and abstract?
5.How do u invoke entity bean from a servlet?
6.What are different ways of communicating between Servlet and JSP? Which one would you recommend?
7. Where do you deploy the class files in weblogic container?