More Servlets and JavaServer Pages™

Chapter 2. A Fast Introduction to Basic Servlet Programming

Topics in This Chapter

• The advantages of servlets over competing technologies

• The basic servlet structure and life cycle

• Servlet initialization parameters

• Access to form data

• HTTP 1.1 request headers, response headers, and status codes

• The servlet equivalent of the standard CGI variables

• Cookies in servlets

• Session tracking

Servlets are Java technology’s answer to Common Gateway Interface (CGI) programming. They are programs that run on a Web server, acting as a middle layer between a request coming from a Web browser or other HTTP client and databases or applications on the HTTP server. Their job is to perform the following tasks, as illustrated in Figure 2-1.

Figure 2-1. The role of Web ...