Servlet to develop the web application dynamicallyPosted by Gyan Guide on April 13th, 2017 Servlet is used to develop the web application ( web application resides at server side and creates dynamic web page).There are many interfaces and classes in the servlet API such as Servlet, GenericServlet, HttpServlet, ServletRequest, ServletResponse etc. Before Servlet, CGI (Common Gateway Interface) scripting language was used as a server-side scripting language. But CGI was having many disadvantages . 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 needs to start a new process. Disadvantage of CGI :
Advantage of Servlet The web container creates threads for handling the multiple requests to the servlet. The basic benefits of servlet are as follows: 1.Good Performance: because it creates a thread for each request . 2.Portable:because it uses java language. 3.Robust:Servlets are managed by JVM so we don't need to worry about memory leak, garbage collection etc. 4.More Secure:because it uses java language.. Servlet Life Cycle A servlet life cycle can be defined as the entire process from its creation to the destruction. The following are the ways followed by a servlet - The servlet is initialized by calling the init () method.java training center bangalore -The servlet calls service() method to process a client's request. -The servlet is exit by calling the destroy() method. -Finally, servlet is garbage collected by the garbage collector of the JVM. The init() method : The init method is invoked only once. init() is invoked when the servlet is first created, and not invoked again for each user request. So, it is used for one-time initializations The init() method creates or loads some data that will be used throughout the life of the servlet. The service() method : The service() method is the main method to perform the task. The servlet container (i.e. web server) calls the service() method to handle requests coming from the user ( browsers) and to write the formatted response back to the user.java/j2ee classes bangalore The destroy() method : The destroy() method is called only once at the end of the life cycle of a servlet. This method gives servlet a chance to close database connections, halt background threads, write cookie lists or hit counts to disk, and perform other such cleanup activities. After the destroy() method is called, the servlet object is marked for garbage collection. Use Of Servlet 1) To accept form input and generate HTML Web pages dynamically. 2) As part of middle tiers in enterprise networks by connecting to SQL databases via JDBC. 3) In conjunction with applets to provide a high degree of interactivity and dynamic Web content generation.best core java training in bangalore 4) Servlets could act as active agents which share data with each other. 5)Servlets could be used for balancing load among servers 6)Protocol support Author : Infocampus provides Advance Java Training in Bangalore with the 100% placement assistance.Attend 4 days free demo classes on java course. Learn Oops concept,packages, thread, servlet,spring and hibernate etc. in best java training institute.Training is provided by the 10+ years experience trainers . Complete practical session is available for java training.Mock test and mock interview are conducted every weekend on java/j2ee classes. To get the free job support call at : 9738001024 or for more information on java course in bangalore visit at : http://www.infocampus.co.in/java-training-bangalore.html Like it? Share it!More by this author |