Skip to main content

Java Servlet

Servlet technology is used to create a web application (resides at server side and generates a dynamic web page).

Servlet technology is robust and scalable because of java language. Before Servlet, CGI (Common Gateway Interface) scripting language was common as a server-side programming language. However, there were many disadvantages to this technology. We have discussed these disadvantages below.

There are many interfaces and classes in the Servlet API such as Servlet, GenericServlet, HttpServlet, ServletRequest, ServletResponse, etc.

What is a Servlet?

Servlet can be described in many ways, depending on the context.

  • Servlet is a technology which is used to create a web application.
  • Servlet is an API that provides many interfaces and classes including documentation.
  • Servlet is an interface that must be implemented for creating any Servlet.
  • Servlet is a class that extends the capabilities of the servers and responds to the incoming requests. It can respond to any requests.
  • Servlet is a web component that is deployed on the server to create a dynamic web page.
Servlet

What is a web application?

A web application is an application accessible from the web. A web application is composed of web components like Servlet, JSP, Filter, etc. and other elements such as HTML, CSS, and JavaScript. The web components typically execute in Web Server and respond to the HTTP request.

CGI (Common Gateway Interface)

CGI technology enables the web server to call an external program and pass HTTP request information to the external program to process the request. For each request, it starts a new process.

CGI vs., Servlet

Disadvantages of CGI

There are many problems in CGI technology:

  1. If the number of clients increases, it takes more time for sending the response.
  2. For each request, it starts a process, and the web server is limited to start processes.
  3. It uses platform dependent language e.g. C, C++, perl.

Advantages of Servlet

Advantages of Servlet

There are many advantages of Servlet over CGI. The web container creates threads for handling the multiple requests to the Servlet. Threads have many benefits over the Processes such as they share a common memory area, lightweight, cost of communication between the threads are low. The advantages of Servlet are as follows:

  1. Better performance: because it creates a thread for each request, not process.
  2. Portability: because it uses Java language.
  3. Robust: JVM manages Servlets, so we don't need to worry about the memory leak, garbage collection, etc.
  4. Secure: because it uses java language.



Anurag Rana

Comments

Post a Comment

Popular posts from this blog

Standard and Formatted Input / Output in C++

The C++ standard libraries provide an extensive set of input/output capabilities which we will see in subsequent chapters. This chapter will discuss very basic and most common I/O operations required for C++ programming. C++ I/O occurs in streams, which are sequences of bytes. If bytes flow from a device like a keyboard, a disk drive, or a network connection etc. to main memory, this is called   input operation   and if bytes flow from main memory to a device like a display screen, a printer, a disk drive, or a network connection, etc., this is called   output operation . Standard Input and Output in C++ is done through the use of  streams . Streams are generic places to send or receive data. In C++, I/O is done through classes and objects defined in the header file  <iostream> .  iostream  stands for standard input-output stream. This header file contains definitions to objects like  cin ,  cout , etc. /O Library Header Files There are...
Post a Comment
Read more

Genetic Algorithm: Population, Fitness Function, Parent Selection, Cross over, Mutation

Genetic Algo Population Population is a subset of solutions in the current generation. It can also be defined as a set of chromosomes. There are several things to be kept in mind when dealing with GA population − The diversity of the population should be maintained otherwise it might lead to premature convergence. The population size should not be kept very large as it can cause a GA to slow down, while a smaller population might not be enough for a good mating pool. Therefore, an optimal population size needs to be decided by trial and error. The population is usually defined as a two dimensional array of –  size population, size x, chromosome size . Population Initialization There are two primary methods to initialize a population in a GA. They are − Random Initialization  − Populate the initial population with completely random solutions. Heuristic initialization  − Populate the initial population using a known heuristic for the problem. It has been observed that the e...
Post a Comment
Read more

C++ (Object and Class)

The major purpose of C++ programming is to introduce the concept of object orientation to the C programming language. Object Oriented Programming is a paradigm that provides many concepts such as  inheritance, data binding, polymorphism etc. The programming paradigm where everything is represented as an object is known as truly object-oriented programming language.  Smalltalk  is considered as the first truly object-oriented programming language. OOPs (Object Oriented Programming System) Object  means a real word entity such as pen, chair, table etc.  Object-Oriented Programming  is a methodology or paradigm to design a program using classes and objects. It simplifies the software development and maintenance by providing some concepts: Object Class Inheritance Polymorphism Abstraction Encapsulation C++ Object In C++, Object is a real world entity, for example, chair, car, pen, mobile, laptop etc. In other words, object is an ent...
Post a Comment
Read more