Http basics by-joshi_29_4_15-ppt

1

HTTP

Hypertext Transfer Protocol

Date: 29-04-2015 By: Raghavendra Joshi

OSI (Open System Interconnection) Model

HTTP: © Qwinix. 20152

Hyper Text Transfer Protocol


What is HTTP?

It is the set of rules for bi-directional transfer of

data on the World Wide Web

Data May be – Images – Text - HTML page – JSON -

XML

HTTP Components


Client – Web browser, Mobile browser, etc..

Web Server – Apache, IIS(Internet Information Server)

from Microsoft.

Resource – Plain text, HTML, Images, JSON, XML etc

URL - Uniform Resource Locator. Where exactly resource

is located on the internet.

URL Syntax


<scheme> : //<host> :<port>

/<path> ;<parameters> ?<query>

#<fragment>Scheme - The protocol you are usingHost - Host name or ip numberPort - TCP port number that protocol server is

usingPath - Path and filename reference of object on

server

HTTP Request Message Syntax


Request-LineHeaders...

Content...blank line

A Request Example


GET /foo/bar/index.html HTTP/1.1

User - Agent: Mozilla/4.0

Host: www.example.com

Accept - Language: en-us

Date: Wed, 29 Apr 2015 10:15:56 GMT

Server: Apache

Last-Modified: Wed, 29 Apr 2015 09:15:56 GMT

Accept-Ranges: bytes

Content-Length: 51

HTTP Response Message Syntax


Status-LineHeaders...

Content...

blank line

HTTP Response Message Syntax

Copyright © Qwinix. 20149

HTTP/1.1 200 OK

Date: Wed, 29 Apr 2015 10:15:56 GMT

Server: Apache/2.2.14 (Win32)

Last-Modified: Wed, 29 Apr 2015 09:15:56 GMT

Accept-Ranges: bytes

Content-Length: 51

Content-Type: text/html

Connection: Closed

<html>

<body>

<h1>Hello, World!</h1>

</body>

</html>

HTTP Methods


GET - Used to retrieve existing

resource identified by the URL HEAD - Used to retrieve meta

information about the existing

resource with out response body. It is

the little brother of GET POST - Used to create a new resource

on the server identified by the URL

HTTP Methods


PUT - Used to update existing

resource identified by the URL DELETE - Used to remove the

existing resource identified by the

URL CONNECT - Establishes a tunnel to a

server identified by URI

HTTP Response


Status-codes 1xx - Informational 100 - When the server receives the request

headers, 100 Continue occurs. In this case,

the client is required to proceed in sending

the request body. 101 – Switching Protocol

The client request has asked the server to switch

protocols and the server is acknowledging that it

will do so and comply with the client's request

HTTP Response


Status-codes 2xx - Success

The action was successfully received,

understood, and accepted 200 OK 201 POST command successful 202 The request is accepted for processing, but

the processing is not complete. 203 - The information in the entity header is from

a local or third-party copy, not from the original

server. 204 - A status code and a header are given in the

response, but there is no entity-body in the reply.

HTTP Response


Status-codes 3xx - Redirection

Further action must be taken in order

to complete request 300 Resource found at multiple

locations 301 Resource moved permanently 302 Resource moved temporarily 304 Resource has not modified (since

date)

HTTP Response


Status-codes 4xx - Client error

The request contains bad syntax or

cannot be fulfilled 400 Bad request from client 401 Unauthorized request 402 Payment required for request 403 Resource access forbidden 404 Resource not found 405 Method not allowed for resource 406 Resource type not acceptable

HTTP Response


Status-codes 5xx - Server error

The server failed to fulfill an

apparently valid request 500 Internal server error 501 Method not implemented 502 Bad gateway or server overload 503 Service unavailable / gateway

timeout 504 Secondary gateway / server

timeout

HTTP < 1.0


Stateless : Server does not

remember any previous requests.

Non Persistent: Separate TCP

connection is needed to serve each

resource.

HTTP 1.1


Server can be made to remember

the previous request using cookies

and sessions.

Persistent: Single TCP connection is

needed to serve multiple resources.

Server leaves the connection open

even after serving the request and

closes connection on timeout.

Proxy Server


It is the dedicated computer or

software system running on a

computer that acts as intermediary

between client and original server. These are used for two purposes Caching As Firewall

Proxy Server


21

For further details, please contact :

Qwinix Technologies Inc 5350 S. Roslyn Street, Suite # 306

Greenwood Village, CO 80111 Tel: 303-459-4310 Fax: (720) 285-1936

[email protected]

US Costa Rica India UAE

Http basics by-joshi_29_4_15-ppt

Software

Transcript of Http basics by-joshi_29_4_15-ppt