Servlet interview questions
There is a list of 20 servlet interview questions. If you know any servlet interview question that has not been included here, kindly post your question in the Ask Question section.
1)How many objects of a servlet is created?
2)What is the life-cycle of a servlet?
3)What are the life-cycle methods for a servlet?
4)Who is responsible to create the object of servlet?
The web container.
5)When servlet object is created?
At the time of first request.
6) What is difference between Get and Post method?
7)What is difference between PrintWriter and ServletOutputStream?
PrintWriter is a character-stream class where as ServletOutputStream is a byte-stream class.The PrintWriter class can be used to write only character-based information whereas ServletOutputStream class can be used to write primitive values as well as character-based information.
8)What is difference between GenericServlet and HttpServlet?
The GenericServlet is protocol independent whereas HttpServlet is HTTP protocol specific.HttpServlet provides additional functionalities such as state management etc.
9)What is servlet collaboration?
When one servlet communicates to another servlet, it is known as servlet collaboration.There are many ways of servlet collaboration:
10)What is the purpose of RequestDispatcher Interface?
The RequestDispacher interface provides the facility of dispatching the request to another resource it may be html, servlet or jsp.This interceptor can also be used to include the content of antoher resource.more details...
11)Can you call a jsp from the servlet?
Yes, one of the way is RequestDispatcher interface for example:more details...
12)What is difference between forward() method of RequestDispatcher and sendRedirect() method ?
13)What is difference between ServletConfig and ServletContext?
The container creates an object of ServletConfig for each servlet whereas an object of ServletContext is created for each web application.
14)What is Session Tracking?
Session simply means a particular interval of time.
Session Tracking is a way to maintain state of an user.Http protocol is a stateless protocol.Each time user requests to the server, server treats the request as the new request.So we need to maintain the state of an user to recognize to particular user.more details...
15) What are Cookies?
A cookie is a small piece of information that is persisted between the multiple client requests.A cookie has a name, a single value, and optional attributes such as a comment, path and domain qualifiers, a maximum age, and a version number.more details...
16) What is difference between Cookies and HttpSession?
Cookie works at client side whereas HttpSession works at server side.
17) What is filter?
A filter is an object that is invoked either at the preprocessing or postprocessing of a request.It is pluggable.more details...
18) How can we perform any action at the time of deploying the project?
With the help of ServletContextListener interface.
19) What is the disadvantage of using cookies?
It will not work if cookie is disabled from the browser.more details...
20) How can we upload the file to the server using servlet?
One of the way is by MultipartRequest class provided by third party.more details...