The ServletContext interface is a part of the Java Servlet API and represents a servlet's view of the web application that it is running within. It is created when the web application starts up and is destroyed when the web application shuts down.

The ServletContext provides a way for servlets to share information about the application, such as initialization parameters, attributes, and resources. It also provides a way to interact with the web container, such as to get information about the server or to create a dispatcher for a resource.

Some of the commonly used methods of ServletContext interface are:

• getInitParameter(String name): returns the value of the initialization parameter with the given name, or null if the parameter does not exist.
• getAttribute(String name): returns the value of the attribute with the given name, or null if the attribute does not exist.
• setAttribute(String name, Object value): sets the value of the attribute with the given name.
• getResource(String path): returns a URL object for a resource that is mapped to the given path, or null if no such resource exists.
• getRequestDispatcher(String path): returns a RequestDispatcher object that is used to forward a request or include a resource in the response.

The ServletContext interface can be obtained by a servlet in different ways, depending on the context in which it is running. For example, it can be obtained by calling the getServletContext() method on a servlet's GenericServlet superclass, or by using the ServletContextEvent mechanism to listen for the context initialization and destruction events.