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Explain the lifecycle of Servlet with block diagram.

 The lifecycle of a Servlet can be divided into several stages. Here's a block diagram that illustrates the different stages:



  1. Servlet API: The Servlet API provides a standard set of interfaces and classes for creating and interacting with Servlets. It is typically included in the web application's classpath as a JAR file.
  2. Servlet Container: The Servlet Container is a web server or application server that implements the Servlet API. It provides a runtime environment for executing Servlets and manages their lifecycle.
  3. Servlet Class: The Servlet Class is the Java class that implements the javax.servlet.Servlet interface. It contains the logic for processing HTTP requests and generating HTTP responses.
  4. init(): The init() method is called once when the Servlet is first loaded by the Servlet Container. It is used for initialization tasks, such as setting up database connections, loading configuration settings, or initializing other resources that will be used by the Servlet.
  5. service() / doGet() / doPost(): The service() method is called for each HTTP request that is handled by the Servlet. It receives an HTTP request and generates an HTTP response. The doGet() and doPost() methods are convenience methods for handling GET and POST requests, respectively, and are typically overridden by the Servlet class to implement the desired behavior.
  6. destroy(): The destroy() method is called when the Servlet is unloaded by the Servlet Container. It is used for cleanup tasks, such as closing database connections, releasing resources, or saving state information.

During the lifecycle of a Servlet, multiple instances of the Servlet class may be created and destroyed by the Servlet Container. The Servlet Container is responsible for managing the lifecycle of Servlets and ensuring that they are initialized, invoked, and destroyed correctly.

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