Murali wrote:
> 
> how do i embedd servlets/jsp code into html or viceversa

You don't embed servlets into html. A Servlet is a java class that runs in a web
server and provides server-side processing. A JSP is java code embedded into
html. The page is compiled into a java servlet (which runs in the server); the
html in the page is translated into code in the servlet that sends the html to
the client.

If you can, check out these resources from Wrox for detailed explanations about
how to write servlets and JSPs:
http://www.wrox.com/Books/Book_Details.asp?sub_section=1&isbn=1861004656&subject=Java&subject_id=13
http://www.wrox.com/Books/Book_Details.asp?sub_section=1&isbn=1861002777&subject=Java&subject_id=13

For online resources check:
http://java.sun.com/products/servlet/technical.html
http://www.apl.jhu.edu/~hall/java/Servlet-Tutorial/

> how can i retreive data from any database(sql/oracle..)
> how to write database connection.

http://java.sun.com/docs/books/tutorial/jdbc/index.html