Hi I'm planning to build a JSP - Servlet Online banking application. All I need to know I mean every single thing for providing the security to the application. like sql injection n all..!! please help me with this.
Don't waste your time with anything on roseindia.net. You'll just learn bad habits and pick up bad code.
As for the security issue, you're asking for a two year education in a forum post. I don't mean to sound harsh, but without an extensive background in security I can pretty much guarantee that anything you design will be so full of holes that a 12 year old could hack it in less than 30 minutes.
"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." -- Ted Nelson
As the others here have mentioned, security isn't trivial. It takes time, research, and experience (and patience!) to master. I recommend that you start by taking a look at the reference materials available at the Open Web Application Security Project (OWASP). Here are some examples: