|Explain the life cycle methods of a Servlet.
The javax.servlet.Servlet interface defines the three methods known
as life-cycle method.
What is the difference between the getRequestDispatcher(String path) method of javax.servlet.ServletRequest interface and javax.servlet.ServletContext interface?
The getRequestDispatcher(String path) method of javax.servlet.ServletRequest interface accepts parameter the path to the resource to be included or forwarded to, which can be relative to the request of the calling servlet. If the path begins with a "/" it is interpreted as relative to the current context root.
The getRequestDispatcher(String path) method of javax.servlet.ServletContext
interface cannot accepts relative paths. All path must sart with a "/"
and are interpreted as relative to curent context root.
Explain the directory structure of a web application.
The directory structure of a web application consists of two parts.
WEB-INF folder consists of
What are the common mechanisms used for session tracking?
ServletContext interface is a window for a servlet to view it's environment.
A servlet can use this interface to get information such as initialization
parameters for the web applicationor servlet container's version. Every
web application has one and only one ServletContext and is accessible to
all active resource of that application.
What is preinitialization of a servlet?
A container doesnot initialize the servlets ass soon as it starts up,
it initializes a servlet when it receives a request for that servlet first
time. This is called lazy loading. The servlet specification defines the
<load-on-startup> element, which can be specified in the deployment
descriptor to make the servlet container load and initialize the servlet
as soon as it starts up. The process of loading a servlet before any request
comes in is called preloading or preinitializing a servlet.
What is the difference between Difference between doGet() and doPost()?
A doGet() method is limited with 2k of data to be sent, and doPost()
method doesn't have this limitation. A request string for doGet() looks
like the following:
What is the difference between HttpServlet and GenericServlet?
A GenericServlet has a service() method aimed to handle requests. HttpServlet
extends GenericServlet and adds support for doGet(), doPost(), doHead()
methods (HTTP 1.0) plus doPut(), doOptions(), doDelete(), doTrace() methods
What is the difference between ServletContext and ServletConfig?
ServletContext: Defines a set of methods that a servlet uses to communicate with its servlet container, for example, to get the MIME type of a file, dispatch requests, or write to a log file.The ServletContext object is contained within the ServletConfig object, which the Web server provides the servlet when the servlet is initialized
ServletConfig: The object created after a servlet is instantiated and its default constructor is read. It is created to pass initialization information to the servlet.
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