A Brief Introduction to Servlets and JSP

In this article we will discuss only HTTP servlets and hence when we mention servlet we mean HTTP Servlet.

A Servlet, in simple terms, is a Java program running under a web server taking a 'request' object as an input and responding back by a 'response' object.

Typically a web browser will send the request in HTTP format. The servlet container will convert that into a request object. Similarly the response object - populated by the servlet is converted into an HTTP response by the servlet container.

This mechanism makes the browser - web server interaction very easy.

You can check the Advantages of Servlets at JavaBoutique: What are the Advantages of Servlets over Traditional CGI?

A Java Server Page (JSP) is syntactically very similar to ASP except for the programming language / Script which is Java in case of JSP.

So similar to ASP one can embed the java code within <% and %> tags with rest of your HTML code , in the same file. The code within <% and %> tags: the Java code is executed on the server and the HTML part with evaluated java code (result) is passed to the requesting client.

You can check advantages of JSP at  What are the Advantages of JSP?

Here are the links to parts of Sun web site about Servlet, Java Servlet API and JavaServer Pages (JSP).

Building Web Applications Using Servlets and JSP
Building Web Applications Using Servlets and JSP
Servlet