HTTP Protocol and Servlets - Quiz Explanation

The correct answers are indicated below, along with text that explains the correct answers.

1.	HTTP (HyperText Transfer Protocol) requests are: Please select the best answer.
	A.	The only way information moves around the Internet
	B.	Used to request HTML from a Web server
	C.	Used to ensure a “stateful” exchange of information over the Internet
	The correct answer is B. HTTP is the way that Web browsers request HTML from Web servers. Whether the Web server just copies out a file, runs a program, or mixes program output with the contents of a file is irrelevant to HTTP. A is incorrect because there are hundreds or even thousands of other transfer protocols, such as SMTP for email, that are used on the Internet. D is incorrect because HTTP is a stateless protocol.

2.	When a Web browser wants to retrieve a file called `welcome.html` from a Web server, it sends this command: Please select the best answer.
	A.	SEND /welcome.html HTTP/1.0
	B.	SEND /welcome.html
	C.	GET /welcome.html HTTP/1.0
	D.	GET /welcome.html
	The correct answer is C. Web browsers request files with a GET request, followed by the full path and file name, and the HTTP level. A and B are incorrect because there is no SEND request in HTTP. D is incorrect because it does not include the HTTP level.

3.	HTTP is a stateless protocol. This means that: Please select the best answer.
	A.	It will work from anywhere in the world
	B.	It’s impossible for the program executing on the Web server to know two requests are from the same user
	C.	Every program must be able to gather all the information it needs from a single Web page
	D.	It is hard work to get the program executing on the Web server to know two requests are from the same user
	The correct answer is D. It is possible to keep track of a user through multiple requests, but it requires alot of effort. A is incorrect because although HTTP does work from anywhere in the world, that does not describe the word stateless. B is incorrect because session tracking isn’t impossible under HTTP, just difficult. C is incorrect because a session can span several Web pages if the right programming techniques have been used.