Basic of Web
What is a web application?
What is a Servlet?
Figure:
Advantages of 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.
What is a Servlet?
- Servlet technology is used to create a web application.
- It is run at server side and generates a dynamic web page.
- Servlet technology is robust and scalable because of java language.
- Servlet is an API that provides many interfaces and classes.
- 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.
Figure:
- Before Servlet, CGI (Common Gateway Interface) scripting language was common as a server-side programming language.
- However, there were many disadvantages to this technology.
- Disadvantages of CGI
- If the number of clients increases, it takes more time for sending the response.
- For each request, it starts a process, and the webserver is limited to start processes.
- It uses platform dependent language e.g. C, C++, perl.
Advantages of Servlet:
- There are many advantages of Servlet over CGI.
- Figure:
- 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.
- Figure:
- The advantages of Servlet are as follows:
- Better performance: because it creates a thread for each request, not process.
- Portability: because it uses Java language.
- Robust: JVM manages Servlets, so we don't need to worry about the memory leak, garbage collection, etc.
- Secure: because it uses java language.
- There are many interfaces and classes in the Servlet API such as Servlet, GenericServlet, HttpServlet, ServletRequest, ServletResponse, etc.
Tags:
Java
