What is Servlet and why it is used?/ what is the servlet life cycle/ What are the Servlet features?/ What is Servlet and Servlet life cycle?

Hello Friends, In this blog post(What is Servlet and Servlet life cycle?) I am going to let you know about the java servlet and how it is processed? A servlet is nothing but a java class that is instantiated by the web server when a servlet gets started.

Within this blog post(What is Servlet and Servlet life cycle?) we will also explore few important questions and answers related to the Java Servlet like:

What are the features of the java servlet?
What is Servlet and why it is used?
What is Servlet’s example?
What is Servlet in HTML?
What is Servlet and how it works?
What is Servlet’s life cycle?
What are Servlet and its types?

interaction between server and srevlet
Servlet and Servlet life cycle

What is Servlet and why it is used?

When this servlet gets started, it means a particular is being called in the form of an HTTP request through the web browser to the webserver.

Code in the servlet method can obtain information about the request and produce information to be included in an HTTP response by calling methods on parameter objects passed to the method.

When the control is shifted from a servlet to the server then the server creates an HTTP response from the information dynamically generated by the servlet.

  1. When an HTTP request message is received by a servlet-capable server, it first determines, based on the URL of the request, that the request should be handled by a servlet.

Understand this with the help of this example, a server might be configured to treat any request to any URL for which the path component begins with servlet as a request that should be handled by a servlet.

  1. The server then determines from the URL, which servlet should handle the request and calls a method on that servlet. Two parameters are passed to the method – an object implementing the HTTPServlet request interface, and an object implementing the HttpServerResponse interface.

Both of these interfaces are defined as part of the Java Servlet API, Which is implemented by the server. The first object provides a method that can be used by the servlet to access the information contained in the HTTP request message received by the server.

The second object can be used to record the information that the servlet wishes to include in the HTTP response message that the server will send to the client(we4b browser) in reply to the request.

  1. The servlet method executes, typically calling methods on the HttpServletRequest and HttpServletResponse object passed to it. The information stored in the later object by the servlet method typically includes an entire HTML document along with some HTTP header information like the document content-type. When the servlet method has finished its processing it returns control to the server.
  2. The server formats the information stored in the HttpServerResponse object by the servlet into an HTTP response message, which it then sends to the client(web browser) that initiated the HTTP request.

The life cycle of a servlet: What is Servlet’s life cycle?/ What is Servlet and Servlet life cycle?

servlet follows the life cycle which governs the multithreaded environment that servlet runs in and provides an insight to some of the mechanism available to a developer for sharing server-side resources.

The servlet follow a three-phase life namely, initialization, service, and destruction.

The initialization is the first phase of the server life-cycle. It represents the creation and initialization of resources. The servlet may require in response to the service request.

The Javax.servlet.servlet interface must be implemented by all servlet. This interface defines the init() method to match the initialization phase of a servlet life-cycle. When a container loads a servlet, invokes the init() method prior to servicing any requests.

The second phase of a servlet life-cycle is the service phase. It represents all the interaction along with the request until the servlet is destroyed. The servlet interface matches the service phase to the service() method. The service() method of a servlet is invoked once as per the request. Then, it is responsible to generate the response to that request.

The third and final phase of the servlet from the container. Here, the servlet interface defines the destroy() method to correspond to the destruction life-cycle phase. When a servlet is to be removed, a container calls the destroy() method.

Features of java servlet: What are the features of the java servlet?

Servlet provides many advantages in comparison with CGI. First, performance is better. Servlet runs within the address space of a web server. It is not required to create a separate process to handle each client request.

Second, servlets are platform-independent since they are written in Java. Third, the java security manager on the server enforces a set of restrictions to protect the resources on a server machine. Finally, the full functionality of the java class libraries is available to a servlet. It can communicate with applets, databases, or other software through the sockets and RMI mechanisms.

Quick Q&A:

What is Servlet’s example?

The various example of servlets are given below:

Jar fileServer
1) servlet-api.jarApache Tomcat
2) weblogic.jarWeblogic
3) javaee.jarJBoss
4) javaee.jarGlassfish
Servlet example

What is Servlet in HTML?

Servlet simply is the java program that is just the extension in the server capability or performance. Webserver displayed the HTML documents and send this response to the user using the HTTP protocol.

What is Servlet and how it works?

The main work of the servlet is to handle the request coming from the web server and send the response back to the webserver.

Conclusion:

So friends, In this blog post(What is Servlet and Servlet life cycle?) we have learned about the Java servlet, here we have gone through the life cycle of the servlet and we have also explored the features of the java servlets. Servlets are Java programs that are used to call the methods or particular methods to retrieve the specific information from the webserver.

Inside this blog post, we have also discussed few important questions like What are the features of the java servlet,
What is Servlet and why is used, What is Servlet’s example, What is Servlet in HTML, What is Servlet and how it works, What is Servlet’s life cycle, What are Servlet and its types.

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Anurag

I am a blogger by passion, a software engineer by profession, a singer by consideration and rest of things that I do is for my destination.