JDBC PROGRAMS

Comments

Post a Comment

Popular posts from this blog

Servlet Advantages and Disadvantages

Servlet Advantage 1.      Servlets provide a way to generate dynamic documents that is both easier to write and faster to run. 2.      provide all the powerfull features of JAVA, such as Exception handling and garbage collection. 3.      Servlet enables easy portability across Web Servers. 4.      Servlet can communicate with different servlet and servers. 5.      Since all web applications are stateless protocol, servlet uses its own API to maintain  session Servlet Disadvantage 1.      Designing in servlet is difficult and slows down the application. 2.      Writing complex business logic makes the application difficult to understand. 3.      You need a Java Runtime Environment on the server to run servlets. CGI is a completely language independent protocol, so you can write CGIs in whatever languages you have available (including Java if you want to). Advantages over CGI The advantages of using Servlets are their fast performance and ease of use combined
Read more

The Deployment Descriptor: web.xml

Image
Before I explain what a deployment descriptor is, we should first understand the web application directory structure WEB APPLICATION DIRECTORY STRUCTURE: A Web application contains a structure hierarchy 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 filesystem separately(This  format is more useful during development) , or in its "packed" WAR file(This format is used  when you distribute your application to be installed) . Any Web Application that is to be deployed in Tomcat has to conform to this directory structure. The format of the structure can be seen in the figure below: Web Application Directory Structure Application Root Directory   - This is the root directory of the Web Application. The name of this directory is named by the developer - for example the default context we created for this module was called "stud
Read more

Session Management

What is a session? A session is pretty much what it sounds, when a user makes a page request to the server, the server creates a temporary session to identify that user. So when that same user goes to another page on that site, the server identifies that user. So a session is a small and temporary unique connection between a server and the user enabling it to identify that user across multiple page requests or visits to that site. Why should a session be maintained? When there is a series of continuous request and response from a same client to a server, the server cannot identify from which client it is getting requests. Because HTTP is a stateless protocol. When there is a need to maintain the conversational state, session tracking is needed. For example, in a shopping cart application a client keeps on adding items into his cart using multiple requests. When every request is made, the server should identify in which client’s cart the item is to be added. So in this sc
Read more