What are the methods available in ServletContextListener interface?

Methods of ServletContextListener Interface

What is getParameter in servlet?

getParameter. public java.lang.String getParameter(java.lang.String name) Returns the value of a request parameter as a String , or null if the parameter does not exist. Request parameters are extra information sent with the request. For HTTP servlets, parameters are contained in the query string or posted form data.

How the getParameter () method will be called?

getParameter() − You call request. getParameter() method to get the value of a form parameter. getParameterValues() − Call this method if the parameter appears more than once and returns multiple values, for example checkbox.

What is request getParameter in JSP?

getParameter(String name) – This method is used to get the value of a request’s parameter. For example at login page user enters user-id and password and once the credentials are verified the login page gets redirected to user information page, then using request.

When to use servletcontextlistener in javatpoint?

If you want to perform some action at the time of deploying the web application such as creating database connection, creating all the tables of the project etc, you need to implement ServletContextListener interface and provide the implementation of its methods. There is only one constructor defined in the ServletContextEvent class.

What’s the difference between a parameter and servletcontext?

Generally, a parameter is a string value that is most commonly known for being sent from the client to the server (e.g. a form post) and retrieved from the servlet request. The frustrating exception to this is ServletContext initial parameters which are string parameters that are configured in web.xml and exist on the server.

Is the context listener in a servlet or JSP?

Making and Using a context listener. Context listener is not a servlet or JSP, it’s a class that implements ServletContextListener interface and provides definition of contextDestroyed() and contextInitialized().

How to receive notification events from servletcontext?

Interface for receiving notification events about ServletContext lifecycle changes. In order to receive these notification events, the implementation class must be either declared in the deployment descriptor of the web application, annotated with WebListener , or registered via one of the addListener methods defined on ServletContext .