Java Servlets

One way to create the interface between the server and client machines is by using Java servlets. A Java servlet is simply a specialized type of Java program that does all of the work of implementing the web-based application. The servlet extracts the input arguments from the client request, runs the application, and sends the output back to the client. Java servlets can take advantage of the built-in security features of the Java language and give the developer access to the enormous code libraries in the Java API.

Servlets work in conjunction with a Java web server that is running on the server machine. When a Java web server detects a request from a client machine, it invokes the servlet. In this chapter we will discuss servlets that respond to the seven HTTP commands ” DELETE , GET , HEAD , OPTIONS , POST , PUT , and TRACE.

In addition to supporting the concept of a servlet, Java is a particularly well-suited language for developing web-based applications. Java can handle all of the data transfer between client and server and can be used for all of the other server-side code as well. Being able to do everything with a single programming language is a great advantage when developing web-based applications.