JEE

Question 1

Describe a servlet

Answer 1

A servlet is a small java program that runs inside a web server

Question 2

Describe GenericServlet

Answer 2

GenericServlet is a protocol-indepent Servlet which contains the service method, with other helper methods that log and gather information about the application and servlet configuration

Question 3

Describe the Servlet interface

Answer 3

The Servlet is a simple interface that contains methods for initializing and destroying the Servlet, as well as servicing requests

Question 4

Describe two ways in which request parameters come

Answer 4

1. Query parameters, also known as URI parameters e.g. GET /index.jsp?productId = 45845545&category=Books
2. or multipart/form data
   e.g POST /index.jsp?returnTo=product page
   Host : www.example.com
   Content-Length: 48
   Content-type: application/x-www-form-urlencoded

Question 5

doDelete() is responsible for _

Answer 5

doDelete() is responsible for deleting the resource at the specified URL

Question 6

doGet() is responsible for _

Answer 6

doGet() is responsible for retrieving the resource at the specified URL

Question 7

doHead() is responsible for _

Answer 7

doHead() is responsible for retrieving the resource at the specified URL, but only headers are returned

Question 8

doOptions() returns _

Answer 8

doOptions() returns which HTTP methods are allowed

Question 9

doPost() is typically used for _

Answer 9

doPost() is typically used for web form submission

Question 10

doPut() _

Answer 10

doPut() stores the supplied entity at the URL

Question 11

doTrace() is used for _

Answer 11

doTrace() is responsible for diagnostic purposes

Question 12

For responding to _ requests, the javax.servlet.http.HttpServlet _ GenericServlet, and implements the _ method to accept only HTTP requests

Answer 12

For responding to HTTP-specific requests, the javax.servlet.http.HttpServlet extends GenericServlet, and implements the service method to accept only HTTP request

Question 13

How do you instruct tomcat to start the servlet immediately when the web application starts

Answer 13

you do this by configuring the web.xml with the following:

1

Question 14

The _ interface is an extension of ServletRequest that provides additional _ information about a received request.

Answer 14

The HttpServletRequest interface is an extension of ServletRequest that provides additional HTTP protocol-specific information about a received request. It specifies dozens of methods that can be used to obtain details about an HTTP request, eg HttpServletRequest request.getContextPath();

Question 15

True or False, as of Java EE7, the only Servlet protocol currently supported is HTTP

Answer 15

True

Question 16

True or False, every servlet implements the javax.servlet.Servlet interface?

Answer 16

true

Question 17

True or False, in almost all cases, Servlet inherit from java.servlet.GenericServlet

Answer 17

True

Question 18

True or False, you should always use the destroy method to clean up resources held up by your Servlet between requests

Answer 18

True

Question 19

What are the responsibilities of a servlet

Answer 19

A servlet receives and responds to requests from web clients, usually across HTTP

Question 20

what does the deployment descriptor do?

Answer 20

the deployment descriptor instructs the web container how the application should be deployed

Question 21

What is the most important capability of the HttpServletRequest?

Answer 21

The most important capability of the HttpServletRequest is to retrieve parameters passed by the client

Question 22

When is the destroy method called?

Answer 22

The destroy method is called when the web application is stopped or undeployed, or when the web container shuts down

Question 23

When is the init method called?

Answer 23

The init method is called when the Servlet starts:

1. if the servlet is configured to start automatically when the web application is deployed and started, that is when it is called
2. otherwise it is called after the first request for the servlet is received