how to store a file n retrieve a file from mysql database using jsp

Hello, you would need to create a field in your database for that.
MySQL has BLOB field type  which is used for storing files.

A blob will work but you should consider the performance impact and space requirements over time. Another option could be to write the file to the file system and then store the file path and information about the file (if you want) in the My SQL tables.
The drawback to using the file system and tables together would be when you need to clean up the files. You will need a process that reads the table then deletes the file from the file system.

is there any source code available to display the file content which is retrieved from the database in jsp/java

I don't thinks so because you can store there any type of file, meanwhile the browser can display only some specific types of files. I would dare to say that the best you can find is a code that would return the file as a file-stream(so you can download the file).

Following link contains a very good example...

http://idevelopment.info/data/Programming/java/jdbc/LOBS/BLOBFileExample.java

Shorter programs...

Write: http://www.kodejava.org/examples/279.html
Read: http://forums.sun.com/thread.jspa?threadID=5212571

is there any code available to  store a file into mysql db?