java ee - authenticate users using servlets

I just started learning java, and ha开发者_如何转开发ve not worked with java ee. I need to authenticate users using servlets. Advise, please, sample code and technical literature. Thank you!

1. create a html form that accept username / password.

2. post these data to a servlet.

3. in doPost() read these data from request check them against database.

4. set some parameter in session that will show your system that this user is authenticated and logged in.

Also See

• Document
• A Simple step by step example + tutorial

Very simple Servlet/JSP related code to get you started. And here is a fine example of Form Based Authentication Using Servlet.