If you’re looking forward to making your career in the Java software development. Then, it is necessary for you to know about the basic of the Java language and about its various component. You can surf for various online free video tutorials. Or else, you can opt for Online Java Certification Course.
The online course because it will cover every aspect of the Java language, that will provide the better understanding of the Java language. Moreover, by applying for the online course you will also get certification for the Java language that will boost your CV.
In this article, I am going to discuss the use of Servlet in the Java Programming. Further, in this article, various other factors like benefits, life cycle and working of the Servlet are also discussed.
You can understand “Servlet” as the technology which helps in creating a web application. It handles the component at the server side. Moreover, the Servlet technology is scalable and robust because of the Java language.
Before the deployment of Servlet technology, Common Gateway Interface(CGI) technology has implemented for the server-side programming language. But, there are various disadvantages of the CGI like increase client on webpage results in slow sending of response.
Also, Servlet API comes with various interfaces and classes like Servlet, HttpServlet, ServletResponse, ServletRequest, GenericServlet, etc. Even, Servlet has the efficiency to extend the capabilities of the servers and respond to any type of requests.
When we talk about the Servlet benefits, there are various benefits of Servlet over the CGI. By comparing with the process, threads have many advantages over the processes such as threads are lightweight, shares a common memory area and cost of communication is low between the threads. Further, shown below are the benefits of Servlet:
- The Servlet is secure due to the utilization of Java language.
- The Servlet uses Java language that results in increases portability.
- The Servlet is known for its better performance because it creates thread not process for every request.
- JVM manages the Servlet, due to which there is no need to worry about any memory leak or garbage collection, etc.
Servlet Life Cycle
The web container maintains the Servlet Lifecycle, and it includes various levels. For understanding the Servlet life cycle, it is necessary to know about its various levels:
- Loading Servlet class: When the web container receives the first servlet request that time, Servlet class is loads. So, the classloader is responsible for loading the servlet class.
- Creating Servlet instance: In the servlet lifecycle, the servlet instance creates only once. The instance of a servlet is created by the web container, after loading the servlet class.
- Invoking init method: After creating the Servlet instance, the web container calls the init method. Using the init method Servlet is initialised, and it holds the complete lifecycle method of the “javax.servlet.Servlet interface.”
- Invoking service method: When servlet request is received, the web container calls for the service method. In case, the servlet not initialized; then it again follows the above three steps and then again calls the service method. So, once the servlet initialised, then it calls the service method.
- Invoking destroy method: Before removing the servlet instance from the service, the web container calls the destroy method. Due to this servlet hold the chances for cleaning up any resources like thread, memory, etc.
Working of Servlet
Before understanding the Servlet, it is necessary for you to learn about the working of Servlet. So, here are some internal details that will help you to know about the servlet program.
While executing the Servlet program, first the server will check whether the Servlet request is running for the first time,
If Servlet request runs for the first time then web container will perform the following tasks:
- Web Container loads the Servlet class.
- The Servlet class object is created by Web container.
- It initialises method passing the ServletConfig object else
- Web container calls the service method by passing request and response objects.
In case of removing the servlet, web container calls the destroy method and this results in stopping the server.
Danish Wadhwa started his career as Business Developer, but after assisting many companies, he realised to start his own venture. Now, as MD & CEO of Webdew, he is sharing his inordinate amount of knowledge on SAAS, Cloud Computing, Digital marketing, Web designing and much more over social media.