Web Application Technologies

Question 1

HTTP Requests

Answer 1

• consist of one or more headers, each on a separate line
• followed by a mandatory blank line
• followed by an optional message body

Question 2

The first line of every HTTP request consists of WHAT three items, separated by spaces?

Answer 2

1. A VERB indicating the HTTP method (i.e. GET, POST)
2. The requested URL and option query string (params)
3. HTTP version being used (HTTP/1.1)

Question 3

The Requested URL?

Answer 3

• The URL typically functions as a name for the resource being requested, together with an optional query string containing parameters that the client is passing to that resource
• The query string is indicated by the ‘?’ character in the URL
  EXAMPLE: /auth/488/page.aspx?uid=129

Question 4

What are some common HTTP Request Headers?

Answer 4

• Referer
• User-Agent
• Host
• Cookie

Question 5

Referer Header

Answer 5

• used to indicate the URL from which the request originated

- EXAMPLE: If the user clicked on a link, the link URL is displayed

Question 6

User-Agent Header

Answer 6

• used to provide information about the browser or other client software that generated the request.

Question 7

Host Header

Answer 7

• specifies the hostname that appeared in the full URL being accessed
• this is necessary when multiple websites are being hosted on the same server

Question 8

Cookie Header

Answer 8

• used to submit additional parameters that the server has issued to the client
• EXAMPLE: SessionId=5B70C71F3FD4963829483484

Question 9

The first line of the HTTP Response consists of WHAT three items?

Answer 9

• The HTTP version being used
• A numeric status code indicating the result of the request (200 is most common)
• A textual “reason phrase” further describing the status of the response (usually ‘OK’); not really used anymore

Question 10

GET method

Answer 10

• most common
• designed to retrieve resources
• it can be used to send parameters to the requested resource in the URL query string

Question 11

POST method

Answer 11

• used to perform actions

- with this method, request parameters can be sent both in the URL query string and in the body of the message

Question 12

General HTTP Headers

Answer 12

• Connection
• Content-Encoding
• Content-Length
• Content-Type
• Transfer-Encoding

Question 13

Connection Header

Answer 13

• tells the other end of the communication whether it should close the TCP connection after the HTTP transmission has completed, or keep it open for further messages

Question 14

Content-Encoding Header

Answer 14

• specifies the type of encoding being used for the content contained in the message body
• EXAMPLE: gzip

Question 15

Content-Type Header

Answer 15

• specifies the type of content contained in the message body, such as ‘text/html’ for HTML documents

Question 16

Transfer-Encoding Header

Answer 16

• specifies any encoding that was performed on the message body to facilitate its transfer over HTTP.

Question 17

Request Headers

Answer 17

• Accept
• Accept-Encoding
• Authorization
• Cookie
• Host
• Origin
• Referer
• User-agent

Question 18

Accept Header

Answer 18

• tells the server what kinds of content the client is willing to accept

Question 19

Accept-Encoding Header

Answer 19

• tells the server what kinds of content encoding the client is willing to accept

Question 20

Authorization Header

Answer 20

• submits credentials to the server

Question 21

User-Agent Header

Answer 21

• provides information about the browser or the client software that generated the request

Question 22

Response Headers

Answer 22

left off here