How to write web Application

A web application programmer must understand concepts related to distributed applications and services, the HTTP protocol, Common Gateway Interface (CGI) programming, HTML/JavaScript programming, user authentication and authorization, session management, data exchange from disparate sources and so on. This column explains the concepts you need to know to write a web application and outlines the steps for writing a simple web application. A typical web application starts when a user clicks a link in an HTML page and causes the browser to instigate an HTTP request transaction with a web server, CGI program and web application server. The targeted server must perform other functions as following:

• Execute business logic
• Retrieve data according to query parameters
• Authenticate and authorize users
• Exchange data with legacy systems

Build the HTML response page dynamically to be passed back to the serverA web application has an accompanying configuration called web.xml. This file contains all the configuration information of the application that web container needs to know in order to deploy and run the application properly. Understanding the web.xml file is important since you are going to have to construct web.xml file as a part of development of your web application. A web application is defined as a series of directories and files in a standard layout. Such a hierarchy can be accessed in its unpacked form, where each directory and file exists in the file system separately, or in a packed form known as a Web Application Archive or WAR file. The former format is more useful during development while the latter is used when you distribute your application to the target platform.

• COMMON TOOLS USED IN WEB APPLICATION

ASP.NET CSS JavaScript CGI Django WebSphere Administrative Console WebSphere Studio VisualAge for Java Developing a web application is a meticulous and a methodical process. Techniques and process of web application development constantly change with advancement of technologies. Apart from this, diversified demands also influence the style and tools to be used in development of web application. Discussion on this topic can't be wrapped in a single post. Shortly we will map a series of posts on "Writing a web application"