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I think you mean: why isn't there a function required in a servlet like the following? public static void main(String[] args) { } Because the main() method is what the Java VM 'boots up' into...it's the first thing the JVM executes. A servlet, however, is running inside a servlet container (e.g., Tomcat), which is running inside a JVM. *That* JVM gets started with a main() method, but unless you intend to run your servlet from the commandline, there's no explicit need for a main() method.
What else can I help you with?
How the pass value from the HTML pages to the servlet?
You need a form to pass value to a servlet. In the form tag, the action element passes the value into the servlet.
Why doesn't a servlet have a main method in it?
A servlet does not have a main method because it is designed to run within a servlet container, such as Apache Tomcat, which manages its lifecycle. Instead of a main method, servlets implement specific methods like doGet() and doPost() to handle HTTP requests and responses. The container invokes these methods in response to client requests, allowing the servlet to focus on processing web interactions rather than standalone execution.
What is servlet mapping?
A Servlet Mapping is a directive in the web.xml that tells the Servlet Container which class to use when a particular Servlet is called. A Servlet is a class within your Java Web Application. Let's say you have a servlet called MyServlet in the com.example.servlet package. You would need to have a Servlet Mapping pointing the path "/MyServlet" to the "com.example.servlet.MyServlet" class. Without the servlet mapping, you would not be able to invoke your servlet because the Servlet container would not know where it is. JSPs are different - they do not need mappings like this. JSPs exist within the WebRoot of the application, so they are always available. Servlets exist in the WEB-INF\Classes directory once your application is deployed.
What are types of servlet?
Http servlet and Generic servlet
What is java servlet chaining?
Servlet Chaining means the output of one servlet act as a input to another servlet. Servlet Aliasing allows us to invoke more than one servlet in sequence when the URL is opened with a common servlet alias. The output from first Servlet is sent as input to other Servlet and so on. The Output from the last Servlet is sent back to the browser. The entire process is called Servlet Chaining.
Which method must to override in Servlet?
There are 3 main types of requests that get processed by a Servlet. They are: • Get • Post • Put Each of them have a corresponding doXXX() method in the Servlet class which would be: • doGet • doPost • doPut You must override either of these methods based on the type of requests that would be processed by your servlet
How do you configure servlet and server for servlet chaining?
To configure servlet chaining, you need to set up multiple servlets in your web application, typically defined in the web.xml file or through annotations. Each servlet processes requests and can forward the response to the next servlet in the chain using the RequestDispatcher's forward() method. Ensure that each servlet is mapped to a specific URL pattern, allowing the initial request to reach the first servlet in the chain. Additionally, manage the flow by handling request attributes to pass data between servlets as needed.
Can insert javascript coding in servlet?
No. Javascript code can be present inside a JSP but not inside a servlet. A Servlet is a pure java class.
How does Apache httpd work?
Tomcat is a servlet container, and the following is how a servlet container works The init, service, and destroy methods are the servlet's lifecycle methods. The init method is called once by the servlet container after the servlet class has been instantiated to indicate to the servlet that it being placed into service. The init method must complete successfully before the servlet can receive any requests. A servlet programmer can override this method to write initialization code that needs to run only once, such as loading a database driver, initializing values, and so on. In other cases, this method is normally left blank. The service method is then called by the servlet container to allow the servlet to respond to a request. The servlet container passes a javax.servlet.ServletRequest object and a javax.servlet.ServletResponse object. The ServletRequest object contains the client's HTTP request information and the ServletResponse encapsulates the servlet's response. These two objects enable you to write custom code that determines how the servlet services the client request. The servlet container calls the destroy method before removing a servlet instance from service. This normally happens when the servlet container is shut down or when the servlet container needs some free memory. This method is called only after all threads within the servlet's service method have exited or after a timeout period has passed. After the servlet container calls destroy, it will not call the service method again on this servlet. The destroy method gives the servlet an opportunity to clean up any resources that are being held (for example, memory, file handles, and threads) and make sure that any persistent state is synchronized with the servlet's current state in memory. For Better Picture, Visit below article full of images to clear the concept : http://shivasoft.in/blog/java/servlet/how-container-handles-the-servlet-request/
How do you run servlets?
Servlets can be run on Web servers like weblogic or websphere or tomcat. The servlet and other components of the j2ee project need to be packaged as an EAR and then deployed on the server. Based on the deployment descriptor we can access the servlet.
Where you can download java servlet development kit2.0?
There is no specific/separate servlet development kit. Servlets can be developed and compiled using the standard JDK and JRE. The only difference being the fact that - to run them you need a web server
What is servlet and why it is used?
servlet is a small program which run on serverside,and it can not be downloaded at client side. java servlets dynamically extends the functionalities of a web server. main use is: session tracking: no of users (unique) visited u'r website. in order to use cookies..
