Tài Liệu HTTP Tiếng Việt

http://vietjack.com/http/index.jsp Copyright vietjack.com

http://vietjack.com/ Trang chia s cc bi hc online min ph Page 1

Mc lc Gii thiu v giao thc HTTP ................................................................................................ 5

i vi c gi ...................................................................................................................... 6

iu kin tin ................................................................................................................... 6

Tng quan v HTTP ............................................................................................................. 6

Cc c trng c bn ....................................................................................................... 6

Cu trc c bn ................................................................................................................ 7

Client ........................................................................................................................... 8

Server ......................................................................................................................... 8

Cc tham s trong HTTP ...................................................................................................... 8

Phin bn HTTP ............................................................................................................... 8

V d ............................................................................................................................ 8

Uniform Resource Identifiers - B nhn din ngun ti nguyn ng nht ......................... 9

V d ............................................................................................................................ 9

Cc nh dng Ngy/Thi gian ......................................................................................... 9

Cc b k t ..................................................................................................................... 9

V d ............................................................................................................................ 9

M ha ni dung ............................................................................................................. 10

V d .......................................................................................................................... 10

Cc kiu a phng tin (media types) .......................................................................... 10

V d .......................................................................................................................... 11

Cc th ngn ng ........................................................................................................... 11

V d .......................................................................................................................... 11

Message trong HTTP ......................................................................................................... 11

Dng u thng bo (start-line) ....................................................................................... 12

Cc trng Header ........................................................................................................ 13

Phn thn thng bo ...................................................................................................... 14

Yu cu (Request) trong HTTP .......................................................................................... 14



Dng Yu cu ................................................................................................................. 15

Method yu cu .............................................................................................................. 15

Request-URI ................................................................................................................... 16

Cc trng Header Yu cu .......................................................................................... 17

Cc v d ca Thng bo Yu cu .................................................................................. 19

Phn hi (Response) trong HTTP ....................................................................................... 20

Dng trng thi ............................................................................................................... 20

Phin bn HTTP ............................................................................................................. 21

M ha trng thi ............................................................................................................ 21

Cc trng Header Phn hi .......................................................................................... 22

Cc v d v Thng bo Phn hi ................................................................................... 22

Phng thc trong HTTP ................................................................................................... 24

Phng thc GET .......................................................................................................... 25

Phng thc HEAD ....................................................................................................... 26

Phng thc POST ....................................................................................................... 27

Phng thc PUT .......................................................................................................... 28

Phng thc DELETE ................................................................................................... 29

Phng thc CONNECT ............................................................................................... 29

Phng thc OPTIONS ................................................................................................. 30

Phng thc TRACE ..................................................................................................... 30

M ha trng thi trong HTTP ............................................................................................. 31

1xx: Thng tin ................................................................................................................. 32

2xx: Thnh cng ............................................................................................................. 32

3xx: S iu hng li .................................................................................................... 33

4xx: Li Client .................................................................................................................. 34

5xx: Li Server ................................................................................................................ 36

Cc trng Header trong HTTP ......................................................................................... 36

General Header .............................................................................................................. 37

Trng Cache-Control ........................................................................................... 37



Trng Connection ................................................................................................ 40

Trng Date ............................................................................................................ 40

Trng Pragma....................................................................................................... 41

Trng Trailer ......................................................................................................... 41

Trng Transfer-Encoding (M ha truyn ti) ................................................. 41

Trng Upgrade ..................................................................................................... 41

Trng Via ............................................................................................................... 42

Trng Warning (Cnh bo) ................................................................................ 42

Cc trng Header yu cu trn Client........................................................................... 42

Trng Accept (Chp nhn) ................................................................................. 42

Trng Accept-Charset ......................................................................................... 43

Trng Accept-Encoding ...................................................................................... 43

Trng Accept-Language ..................................................................................... 43

Trng Authorization (S y quyn) ................................................................... 44

Trng Cookie ........................................................................................................ 44

Trng Expect ........................................................................................................ 44

Trng From ........................................................................................................... 44

Trng Host ............................................................................................................ 45

Trng If-Match ...................................................................................................... 45

Trng If-Modified-Since ...................................................................................... 45

Trng If-None-Match ........................................................................................... 46

Trng If-Range ..................................................................................................... 46

Trng If-Unmodified-Since ................................................................................. 46

Trng Max-Forwards ........................................................................................... 47

Trng Proxy-Authorization .................................................................................. 47

Trng Range ......................................................................................................... 47

Trng Referer ....................................................................................................... 48

Trng TE ............................................................................................................... 48

Trng User-Agent ................................................................................................ 49



Cc trng Phn hi t Server ....................................................................................... 49

Trng Accept-Ranges ......................................................................................... 49

Trng Age ............................................................................................................. 49

Trng ETag ........................................................................................................... 50

Trng Location ..................................................................................................... 50

Trng Proxy-Authenticate ................................................................................... 50

Trng Retry-After ................................................................................................. 51

Trng Server ......................................................................................................... 51

Trng Set-Cookie ................................................................................................. 51

Trng Vary ............................................................................................................ 52

Trng WWW-Authenticate .................................................................................. 53

Entity Headers ................................................................................................................ 53

Trng Allow ........................................................................................................... 53

Trng Content-Encoding .................................................................................... 53

Trng Content-Language ................................................................................... 54

Trng Content-Length ......................................................................................... 54

Trng Content-Location ...................................................................................... 54

Trng Content-MD5 ............................................................................................. 55

Trng Content-Range ......................................................................................... 55

Trng Content-Type ............................................................................................ 56

Trng Expires ....................................................................................................... 56

Trng Last-Modified ............................................................................................ 56

Caching trong HTTP ........................................................................................................... 56

M ha URL trong HTTP .................................................................................................... 59

Bo mt trong HTTP ........................................................................................................... 66

S r r thng tin c nhn ................................................................................................ 66

S tn cng da trn cc tn Path v File ...................................................................... 67

Vic nh la DNS (DNS Spoofing) ............................................................................... 67

V tr cc Header v vic nh la ................................................................................... 68



y nhim xc minh ......................................................................................................... 68

Cc s y quyn v vic ghi vo b nh n ................................................................... 68

V d v Message trong HTTP ............................................................................................ 68

V d 1 ............................................................................................................................ 68

Client yu cu: ......................................................................................................... 68

Server phn hi: ...................................................................................................... 69

V d 2 ............................................................................................................................ 69

Client yu cu .......................................................................................................... 69

Server phn hi ....................................................................................................... 69

V d 3 ............................................................................................................................ 70

Client yu cu .......................................................................................................... 70

Server phn hi ....................................................................................................... 70

V d 4 ............................................................................................................................ 71

Client yu cu .......................................................................................................... 71

Server phn hi ....................................................................................................... 71

Ti liu tham kho v HTTP ................................................................................................ 72

Cc ng link hu ch v HTTP ................................................................................... 72

Gii thiu v giao thc HTTP HTTP l vit tt ca Giao thc truyn ti siu vn bn (Hypertext Transfer Protocol) l mt giao

thc cp ng dng cho cc h thng thng tin phn phi, cng tc v a phng tin. y l

nn tng cho giao tip thng tin cho World Wide Web (v d: Internet) t 1990. HTTP l mt giao

thc chung v stateless m c th c s dng cho cc mc ch khc cng nh cc s m

rng ca cc phng thc yu cu, cc code li v Header ca n.

Phn hng dn ny c xy dng trn c s cc chi tit k thut RFC-2616, m xc nh giao

thc c lin quan nh HTTP/1.1. HTTP/1.1 l mt phin bn ca HTTP ban u (HTTP/1.0). S

khc bit ln gia HTTP/1.0 v HTTP/1.1 l HTTP/1.0 s dng mt kt ni mi cho mi Yu



cu/Phn hi trao i, trong khi kt ni trong HTTP/1.1 c th c s dng cho mt hoc

nhiu Yu cu/Phn hi trao i.

Lot bi hng dn ca chng ti da trn ngun ti liu ca: Tutorialspoint

i vi c gi Phn hng dn ny c chun b cho cc hc vin nghin cu v khoa hc my tnh v cc

nh pht trin web gip h c kin thc c bn v cc khi nim cc mc pht trin ca

HTTP.

iu kin tin Trc khi tin hnh hc tp vi phn hng dn ny, n l tt cho bn khi bn c mt s hiu bit

c bn v cc khi nim web, cc trnh duyt web, cc Server, v phn mm xy dng trn c s

cu trc Server-Client.

Tng quan v HTTP HTTP l mt giao thc cp ng dng cho cc h thng thng tin phn phi, cng tc, a

phng tin. y l nn tng cho giao tip d liu cho WWW (v d: Internet) t 1990. HTTP l

mt giao thc chung v stateless m c th c s dng cho cc mc ch khc cng nh cc

s co gin ca cc phng thc yu cu, cc code li v Header ca n.

Theo c bn, HTTP l mt giao thc giao tip trn c s TCP/IP, m c s dng phn phi

d liu (cc tp HTML, cc file nh, ) trn WWW. Cng mc nh l TCP 80, nhng cc cng

khc cng c th c s dng. N cung cp mt cch c tiu chun ha cho cc my tnh

giao tip vi nhau. Chi tit k thut HTTP xc nh cch m d liu yu cu ca Client s c xy

dng v c gi ti Server, v cch Server phn hi cc yu cu ny.

Cc c trng c bn C 3 c trng c bn m lm HTTP tr thnh mt giao thc n gin nhng y sc mnh:

HTTP l giao thc connectionless (kt ni khng lin tc): Client ca HTTP, v d: mt

trnh duyt khi to mt yu cu HTTP v sau mt yu cu c to ra, Client ngt kt

ni t Server v i cho mt phn hi. Server x l yu cu v thit lp li s kt ni vi

Client gi phn hi tr li.



HTTP l mt phng tin c lp: N ngha l, bt k loi d liu no cng c th c

gi bi HTTP min l Server v Client bit cch kim sot ni dung d liu. N c

yu cu cho Client cng nh Server xc nh kiu ni dung bi s dng kiu MIME thch

hp.

HTTP l stateless: Nh c cp trn, HTTP l connectionless v n mt kt qu

trc tip l HTTP tr thnh mt giao thc Stateless. Server v Client bit v nhau chi trong

mt yu cu hin ti. Sau , c hai chng n qun tt c v nhau. Do bn cht ca giao

thc, c Client v cc trnh duyt c th gi li thng tin gia cc yu cu khc nhau gia

cc trang web.

HTTP/1.0 s dng mt kt ni mi cho mi trao i Yu cu/Phn hi (Request/Reponse), trong

khi m kt ni ca HTTP/1.1 c th c s dng cho mt hoc nhiu trao i Yu cu/Phn hi.

Cu trc c bn S di y ch cu trc rt n gin ca mt ng dng web v miu t v tr ca HTTP:



Giao thc HTTP l mt giao thc Yu cu/Phn hi da trn cu trc Client/Server, ni m cc

trnh duyt web, cc thit b tm kim, hot ng nh cc Client, v cc Server web hot ng

nh mt Server.

Client

Client gi mt yu cu ti Server theo mu ca mt phng thc yu cu, URI, v phin bn giao

thc, c theo bi mt thng bo MIME cha cc b chnh sa yu cu, thng tin Client, v ni

dung i tng c th qua mt kt ni TCP/IP.

Server

Server phn hi vi mt dng trng thi, bao gm phin bn giao thc ca thng bo v mt code

thnh cng hoc li, theo sau bi mt thng bo MIME cha thng tin Server, thng tin thc th a

phng tin v ni dung i tng c th.

Cc tham s trong HTTP Chng ny lit k mt s cc Tham s giao thc HTTP v c php ca chng m theo chng

c s dng trong giao tip. V d, nh dng ngy thng, nh dng URL, . iu ny s gip

bn trong vic xy dng yu cu ca bn v cc thng tn phn hi trong khi vit cc chng trnh

Client hoc Server. Bn s thy s hu ch hon ton ca nhng tham s ny trong cc chng

k tip trong khi hc tp v cu trc thng bo cho cc yu cu v cc phn hi HTTP.

Phin bn HTTP HTTP s dng mt s nh s . ch phin bn ca giao thc. Phin bn

ca mt thng bo HTTP c ch bi mt trng HTTP-Version trong dng u tin. Ti y l c

php chung ca vic xc nh s phin bn HTTP:

HTTP-Version = "HTTP" "/" 1*DIGIT "." 1*DIGIT

V d

HTTP/1.0

or

HTTP/1.1



Uniform Resource Identifiers - B nhn din ngun ti nguyn ng nht URI l mt chui c nh dng, nhy cm vi ch hoa-thng (case-insentive) theo mt cch

n gin cha tn, v tr,.. xc nh mt ngun, v d, mt website, mt dch v web, . Mt c

php chung ca URI c s dng cho HTTP nh sau:

URI = "http:" "//" host [ ":" port ] [ abs_path [ "?" query ]]

y, nu port l trng hoc khng c cung cp, th port 80 c cho l cho HTTP v

mt abs_path trng l tng ng vi mt abs_path l /. Cc k t khc trong cc b thit

lp reserved v unsafe l tng ng vi m ha % HEX HEX ca chng.

V d

Di y l 3 v d v URI m tng ng nhau:

http://abc.com:80/~smith/home.html

http://ABC.com/%7Esmith/home.html

http://ABC.com:/%7esmith/home.html

Cc nh dng Ngy/Thi gian Tt c cc nhn Ngy/Thi gian HTTP Phi c biu din trong Greenwich Mean Time (GMT),

khng c s ngoi tr. Cc ng dng HTTP c cho php s dng 3 nhn i din Ngy/Thi

gian sau:

Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123

Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036

Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format

Cc b k t Chng ta s dng cc b k t xc nh cc thit lp k t m Client a thch. Nhiu b thit lp

k t c th c lit k ring bit bi cc du phy. Nu mt gi tr l khng c xc nh, mc

nh l US-ASII.

V d

Di y l cc b k t c hp l:

US-ASCII



or

ISO-8859-1

or

ISO-8859-7

M ha ni dung Mt gi tr m ha ni dung ch rng mt thut ton m ha c s dng m ha ni dung

trc khi truyn n ti mng. M ha ni dung c s dng ln u cho php mt ti liu

c nn hoc ngoi ra c truyn ti m khng tht lc s nhn din.

Tt c cc gi tr m ha ni dung l khng phn bit kiu ch (case-insensitive). HTTP/1.1 s

dng cc gi tr m ha ni dung trong cc trng Accept-Encoding v Content-EncodingHeader

m chng ta s quan st trong cc chng k tip.

V d

Di y l cc s m ha hp l:

Accept-encoding: gzip

or

Accept-encoding: compress

or

Accept-encoding: deflate

Cc kiu a phng tin (media types) HTTP s dng cc Kiu phng tin Internet trong cc trng Content-Type v Accept cung

cp d liu m v c th m rng. Tt c cc gi tr kiu phng tin c ng k vi IANA

(Internet Assigned Number Authority). C php chung xc nh kiu phng tin nh sau:

media-type = type "/" subtype *( ";" parameter )



Cc thuc tnh type, subtype, v parameter l case-insensitive.

V d

Accept: image/gif

Cc th ngn ng HTTP s dng cc th ngn ng trong cc trng Accept-Language v Content-Language. Mt

th ngn ng bao gm mt hoc nhiu phn: Mt th ngn ng s cp v mt dy cc th ph:

language-tag = primary-tag *( "-" subtag )

Cc khong trng khng c cho php trong th v tt c cc th l case-insentive.

V d

Cc th v d bao gm:

en, en-US, en-cockney, i-cherokee, x-pig-latin

Hai ch primary-tag l mt ch vit tt cho ngn ng trong ISO-639 v hai k t u tin trong th

ph subtag l m quc gia.

Message trong HTTP HTTP c xy dng trn c s m hnh cu trc Client-Server v giao thc Stateless cc Yu

cu/Phn hi m iu hnh bi vic trao i cc thng bo (Message) dc theo mt kt ni

TCP/IP.

Mt Client l mt chng trnh (mt trnh duyt hoc bt k Client) m thit lp mt kt ni ti mt

Server cho mc ch gi mt hoc nhiu thng bo yu cu HTTP. Mt HTTP Server l mt

chng trnh (hiu theo cch chung l mt Server web nh Apache Server web hoc Internet

Information Services IIS ) m chp nhn cc kt ni phc v cc yu cu HTTP bi vic gi

cc thng bo phn hi HTTP.

HTTP s dng URI nhn din mt ngun cho v thit lp mt kt ni. Mt khi mt kt ni

c thit lp, Cc Thng bo HTTP c truyn trong mt nh dng tng t nh c s

dng trong th in t Internet Mail [RFC5322] v MIME (Multipurpose Internet Mail Extensions)

[RFC2045]. Cc thng bo ny bao gm cc Yu cu t Client ti Server v cc Phn hi t

Server ti Client m s theo nh dng sau:



HTTP-message = | ; HTTP/1.1 messages

Cc yu cu HTTP v cc phn hi HTTP s dng mt nh dng thng bo chung ca RFC 822

cho truyn tri d liu c yu cu. nh dng thng bo chung ny bao gm 4 mc:

Mt dng u tin

Khng hoc nhiu trng Header theo sau bi CRLF.

Mt dng trng (v d: mt dng m khng c g trc CRLF), ch phn cui ca trng

Header.

Mt thn thng bo ty

Trong cc mc tip theo, chng ta s gii thch tng mc c s dng trong thng bo HTTP.

Dng u thng bo (start-line) Mt dng u s c c php chung nh sau:

start-line = Request-Line | Status-Line

Chng ta s bn lun Request-Line v Status-Line trong khi tho lun v cc thng bo Yu cu

HTTP v Phn hi HTTP tng ng. By gi, chng ta xem xt mt s v d v dng bt u trong

trng hp yu cu v phn hi



GET /hello.jsp HTTP/1.1 (This is Request-Line sent by the client)

HTTP/1.1 200 OK (This is Status-Line sent by the server)

Cc trng Header Cc trng Header cung cp thng tin c yu cu v yu cu hoc phn hi, hoc v i tng

c gi trong thn thng bo. C 4 kiu ca Header trong cc thng bo HTTP:

Kiu chung (General-Header): Cc trng Header ny c kh nng ng dng chung cho

c cc thng bo yu cu v phn hi.

Kiu yu cu (Request-Header): Cc trng Header ny ch c kh nng p dng cho cc

thng bo yu cu.

Kiu phn hi (Response-Header): Cc trng Header ny ch c kh nng p dng cho

cc thng bo phn hi.

Kiu thc th (Entity-Header): Cc trng ny xc nh thng tin v thn-thc th hoc,

nu khng c phn thn no hin th, v ngun c nhn din bi yu cu.

Tt c cc Header c cp trn theo mt nh dng chung v mi mt trng Header bao

gm mt tn c theo sau bi mt du hai chm (:) v gi tr trng nh sau:

message-header = field-name ":" [ field-value ]

Di y l v d v cc trng Header a dng:

User-Agent: curl/7.16.3 libcurl/7.16.3 OpenSSL/0.9.7l zlib/1.2.3

Host: www.example.com

Accept-Language: en, mi

Date: Mon, 27 Jul 2009 12:28:53 GMT

Server: Apache

Last-Modified: Wed, 22 Jul 2009 19:15:56 GMT

ETag: "34aa387-d-1568eb00"

Accept-Ranges: bytes

Content-Length: 51

Vary: Accept-Encoding

Content-Type: text/plain



Phn thn thng bo Phn thn thng bo l ty cho mt thng bo HTTP nhng nu n l c sn, th khi n c

s dng mang phn thn c lin kt vi yu cu hoc phn hi. Nu phn thn thc th

c lin kt, th sau thng cc dng Content-Type v Content-Length xc nh bn cht ca

phn thn c lin kt.

Mt phn thn thng bo l phn m mang d liu yu cu HTTP thc s (bao gm d liu mu

v c ti ln,) v d liu phn hi HTTP t Server (bao gm cc file, nh, ). Di y l ni

dung n gin ca mt phn thn thng bo:

Hello, World!

Hai chng ti chng ta s bn v cch s dng ca cc khi nim c gii thch chun b

Cc yu cu HTTP v Cc phn hi HTTP.

Yu cu (Request) trong HTTP Mt Client gi mt yu cu HTTP ti mt Server trong mu mt thng bo yu cu m bao gm

nh dng sau:

Mt dng yu cu

Khng hoc nhiu hn trng Header (General|Request|Entity) c theo sau bi CRLF.



Mt dng trng (v d: mt dng khng c g ng trc CRLF) ch phn kt thc ca

trng Header.

Mt phn thn thng bo ty

Cc phn di gii thch cch s dng ca mi i tng trong thng bo yu cu HTTP.

Dng Yu cu Dng Yu cu bt u vi mt th tc method, c theo sau bi mt Request-URI v phin bn

giao thc, v kt thc vi CRLF. Cc yu t c phn bit ring r bi cc k t khong trng

SP.

Request-Line = Method SP Request-URI SP HTTP-Version CRLF

Di y tho lun v mi phn c cp trong Dng Yu cu.

Method yu cu method yu cu ch phng thc c thc hin trn ngun c nhn din biRequest-

URI cung cp. Method l case-intensive v nn lun lun c cp trong ch hoa. Bng

di y lit k tt c cc method c h tr trong HTTP/1.1.

STT Phng thc v Miu t

1 GET

GET c s dng ly li thng tin t Server cung cp bi s dng

mt URI cung cp. Cc yu cu s dng GET nn ch nhn d liu v

nn khng c nh hng g ti d liu.



2 HEAD

Tng t nh GET, nhng n truyn ti dng trng thi v khu vc

Header.

3 POST

Mt yu cu POST c s dng gi d liu ti Server, v d, thng tin

khch hng, file ti ln, , bi s dng cc mu HTML.

4 PUT

Thay i tt c cc i din hin ti ca ngun mc tiu vi ni dung c

ti ln.

5 DELETE

G b tt c cc i din hin ti ca ngun mc tiu bi URI.

6 CONNECT

Thit lp mt tunnel ti Server c xc nh bi URI cung cp.

7 OPTIONS

Miu t cc chc nng giao tip cho ngun mc tiu.

8 TRACE

Trnh by mt vng lp kim tra thng bo song song vi path ti ngun

mc tiu.

Request-URI Request-URI l mt B nhn din Ngun ng nht (URI) v xc nh ngun m p dng yu cu.

Di y l cc mu thng c s dng xc nh mt URI:



Request-URI = "*" | absoluteURI | abs_path | authority

STT Phng thc v Miu t

1 Mt du * c s dng khi mt yu cu HTTP khng p dng ti

mt ngun c th, nhng ti chnh Server , v ch c cho php

khi phng thc c s dng khng cn thit p dng ti mt

ngun. V d:

OPTIONS * HTTP/1.1

2 absoluteURI c s dng khi mt yu cu HTTP ang c to ra

cho mt s y nhim. S y nhim c yu cu chuyn ti yu cu

hoc dch v t mt cache hiu lc, v tr li phn hi. V d:

GET http://www.w3.org/pub/WWW/TheProject.jspl HTTP/1.1

3 Mu ph bin nht ca Request-URI c s dng xc nh mt

ngun trn mt Server hoc gateway ban u. V d, mt Client mong

mun ly c mt ngun mt cch trc tip t Server ban u s

to mt kt ni TCP ti port 80 ca host www.w3.org v gi cc dng

sau:

GET /pub/WWW/TheProject.html HTTP/1.1

Host: www.w3.org

Ghi ch rng, ng truyn tuyt i khng th l trng rng; nu khng g

c trnh by trong URI ban u, n Phi c cung cp nh l /

(Server root).

Cc trng Header Yu cu Chng ta s hc General-Header v Entity-Header trong mt chng ring khi chng ta s hc v

cc trng Header. By gi, chng ta xem cc trng Header yu cu l g:



Cc trng Request-Header cho php Client truyn thng tin thm v yu cu, v v chnh Client

, ti Server. Nhng trng ny hot ng nh cc b chnh sa yu cu. Di y l mt danh

sch cc trng Request-Header quan trng m c th c s dng da trn s yu cu:

Accept-Charset

Accept-Encoding

Accept-Language

Authorization

Expect

From

Host

If-Match

If-Modified-Since

If-None-Match

If-Range

If-Unmodified-Since

Max-Forwards

Proxy-Authorization

Range

Referer

TE

User-Agent

Bn c th t to cc trng cho mnh trong trng hp bn ang vit Client v Server cho ring

mnh.



Cc v d ca Thng bo Yu cu By gi chng ta t tt c nhng th hc trn cng vi nhau to mt yu cu HTTP

ch th trang hello.htm t Server chy trn tutorialspoint.com.

GET /hello.htm HTTP/1.1

User-Agent: Mozilla/4.0 (compatible; MSIE5.01; Windows NT)

Host: www.tutorialspoint.com

Accept-Language: en-us

Accept-Encoding: gzip, deflate

Connection: Keep-Alive

Ti y chng ta khng gi bt c yu cu d liu ti Server bi v chng ta ang ch th mt trang

thun HTML t Server. Kt ni l General-Header, v phn cn li ca Header l cc Header yu

cu. V d sau y ch cch gi d liu mu ti Server bi s dng phn thn thng bo yu

cu:

POST /cgi-bin/process.cgi HTTP/1.1



Content-Type: application/x-www-form-urlencoded

Content-Length: length




licenseID=string&content=string&/paramsXML=string

y, URl c cung cp /cgi-bin/process.cgi s c s dng x l d liu c truyn v

theo , mt phn hi s c tr li. y content-type ni cho Server rng d liu c truyn

l mt d liu mu web n gin v length s l di thc ca d liu t trong phn thn thng

bo. V d sau ch cch bn c th truyn XML thun ti Server ca bn.




Content-Type: text/xml; charset=utf-8

Content-Length: length






string

Phn hi (Response) trong HTTP Sau khi nhn v phin dch mt thng bo yu cu, mt Server gi tn hiu phn hi vi mt thng

bo phn hi HTTP.

Mt dng trng thi (Status-Line)

Khng hoc nhiu hn cc trng Header (General|Response|Entity) c theo sau bi

CRLF.

Mt dng trng (v d: mt dng m khng c g ng trc CRLF) ch phn kt thc ca

cc trng Header.

Mt phn thn thng bo ty .

Cc khu vc di y gii thch cch s dng ca mi i tng trong mt thng bo phn hi

HTTP.

Dng trng thi Mt dng trng thi bao gm phin bn giao thc c theo sau bi mt m ha trng thi s v

cm t thun vn bn c lin kt ca n.



Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase CRLF

Phin bn HTTP Mt Server h tr phin bn HTTP/1.1 s tr li thng tin phin bn nh sau:

HTTP-Version = HTTP/1.1

M ha trng thi Yu t Status-Code l mt s nguyn 3 k t, trong k t u tin ca m ha trng thi nh

ngha hng (loi) phn hi v hai k t cui khng c bt c vai tr phn loi no. C 5 gi tr ca

k t u tin:

STT M v miu t

1 1xx: Thng tin

N ngha l yu cu c nhn v tin trnh ang tip tc.

2 2xx: Thnh cng

N ngha l hot ng c nhn, c hiu, v c chp nhn mt

cch thnh cng.

3 3xx: S iu hng li

N ngha l hot ng phi c thc hin hon thnh yu cu.

4 4xx: Li Client

N ngha l yu cu cha c php khng chnh xc hoc khng c thc

hin.

5 5xx: Li Server

N ngha l Server tht bi vi vic thc hin mt yu cu nhn nh c v



kh thi.

M ha trng thi HTTP l c th co gin v ng dng HTTP khng c yu cu hiu ngha

ca tt c cc m trng thi c ng k. Mt danh sch ca tt c cc m trng thi c

cung cp trong mt chng ring bit cho bn tham kho.

Cc trng Header Phn hi Chng ta s hc General-Header v Entity-Header trong mt chng ring bit khi chng ta s hc

v cc trng Header. By gi, chng ta tm hiu xem cc trng Header phn hi l g:

Cc trng Header phn hi cho php Server truyn thng tin thm v phn hi m khng th

c t trong dng Status-Line. Nhng trng Header ny cung cp thng tin v Server v v

truy cp t xa ti ngun c xc nh bi Request-URI.

Accept-Ranges

Age

ETag

Location

Proxy-Authenticate

Retry-After

Server

Vary

WWW-Authenticate

Bn c th to ra cc trng ca ring bn trong trng hp bn ang vit Client v Server cho

ring bn.

Cc v d v Thng bo Phn hi By gi chng ta t tt c cc th trn cng vi nhau to mt phn hi HTTP cho mt yu cu

ch th trang hello.jsp t Server ang chy trn tutorialspoint.com.



HTTP/1.1 200 OK

Date: Mon, 27 Jul 2009 12:28:53 GMT

Server: Apache/2.2.14 (Win32)


Content-Length: 88

Content-Type: text/html

Connection: Closed

Hello, World!

V d sau y ch mt thng bo phn hi HTTP hin th trng thi li khi Server khng th tm thy

trang c yu cu:

HTTP/1.1 404 Not Found

Date: Sun, 18 Oct 2012 10:36:20 GMT


Content-Length: 230

Connection: Closed

Content-Type: text/html; charset=iso-8859-1

404 Not Found

Not Found

The requested URL /t.jspl was not found on this server.

Tip theo l mt v d ca mt thng bo phn hi HTTP ch trng thi li khi Server nhp vo mt

phin bn HTTP sai trong yu cu HTTP cung cp:

HTTP/1.1 400 Bad Request



Date: Sun, 18 Oct 2012 10:36:20 GMT


Content-Length: 230

Content-Type: text/html; charset=iso-8859-1

Connection: Closed

400 Bad Request

Bad Request

Your browser sent a request that this server could not understand.

The request line contained invalid characters following the protocol string.

Phng thc trong HTTP p hp cc phng thc ph bin cho HTTP/1.1 c xc nh bn di v b thit lp ny c th

c m rng da trn cc s yu cu. Nhng tn method ny l case-sensitive v chng phi

c s dng trong dng ch hoa.

STT Phng thc v miu t

1 GET

GET c s dng ly li thng tin t Server cung cp bi s dng

mt URI cung cp. Cc yu cu s dng GET nn ch nhn d liu v

nn khng c nh hng g ti d liu.

2 HEAD

Tng t nh GET, nhng n truyn ti dng trng thi v khu vc



Header.

3 POST

Mt yu cu POST c s dng gi d liu ti Server, v d, thng tin

khch hng, file ti ln, , bi s dng cc mu HTML.

4 PUT

Thay i tt c cc i din hin ti ca ngun mc tiu vi ni dung c

ti ln.

5 DELETE

G b tt c cc i din hin ti ca ngun mc tiu bi URI.

6 CONNECT

Thit lp mt tunnel ti Server c xc nh bi URI cung cp.

7 OPTIONS

Miu t cc chc nng giao tip cho ngun mc tiu.

8 TRACE

Trnh by mt vng lp kim tra thng bo song song vi path ti ngun

mc tiu.

Phng thc GET Mt yu cu GET ly d liu t mt Server bi vic xc nh cc tham s trong on URL ca yu

cu. y l phng thc chnh c s dng thu hi ti liu. V d sau ch cch s dng ca

phng thc GET ch th hello.htm:

GET /hello.htm HTTP/1.1








Server s phn hi li yu cu trn l nh sau:

HTTP/1.1 200 OK

Date: Mon, 27 Jul 2009 12:28:53 GMT



ETag: "34aa387-d-1568eb00"

Vary: Authorization,Accept


Content-Length: 88


Connection: Closed

Hello, World!

Phng thc HEAD Phng thc HEAD l c chc nng tng t nh GET, ngoi tr l Server phn hi vi mt

dng v cc Header phn hi, nhng khng c phn thn i tng. V d sau ch cch s dng

ca phng thc HEAD ch th thng tin Header v hello.htm:

HEAD /hello.htm HTTP/1.1






Server phn hi li yu cu HEAD trn nh sau:

HTTP/1.1 200 OK



Date: Mon, 27 Jul 2009 12:28:53 GMT



ETag: "34aa387-d-1568eb00"



Content-Length: 88


Connection: Closed

Bn ch rng ti y Server khng gi bt c d liu no sau Header.

Phng thc POST Phng thc POST c s dng khi bn mun gi mt vi d liu ti Server, v d, cp nht

file, d liu mu, . V d sau y ch cch s dng ca phng thc POST gi mt d liu

mu ti Server, m s c x l bi mt process.cgi v cui cng mt phn hi s c tr li:




Content-Type: text/xml; charset=utf-8

Content-Length: 88




string

Bn Server, scipt process.cgi x l d liu truyn v gi phn hi nh sau:

HTTP/1.1 200 OK

Date: Mon, 27 Jul 2009 12:28:53 GMT



ETag: "34aa387-d-1568eb00"



Content-Length: 88




Connection: Closed

Request Processed Successfully

Phng thc PUT Phng thc PUT c s dng yu cu Server lu gi phn thn i tng c bao

gm ti mt v tr c xc nh bi URL cung cp. V d sau yu cu Server lu phn thn i

tng cung cp trong hello.htm ti root ca Server:

PUT /hello.htm HTTP/1.1





Content-type: text/html

Content-Length: 182

Hello, World!

Server s lu phn thn i tng trong tp hello.jsp v s gi phn hi sau tr li Client:

HTTP/1.1 201 Created

Date: Mon, 27 Jul 2009 12:28:53 GMT



Content-length: 30

Connection: Closed

The file was created.



Phng thc DELETE Phng thc DELETE c s dng yu cu Server xa mt file ti v tr c xc nh

bi URL cung cp. V d sau yu cu Server xa tp cho hello.htm ti root ca Server:

DELETE /hello.htm HTTP/1.1





Server s xa mt tp c cp v s gi phn hi tr li ti Client:

HTTP/1.1 200 OK

Date: Mon, 27 Jul 2009 12:28:53 GMT



Content-length: 30

Connection: Closed

URL deleted.

Phng thc CONNECT Phng thc CONNECT c s dng bi Client thnh lp mt kt ni mng ti Server qua

HTTP. V d sau yu cu mt kt ni vi mt Server ang chy trn hosttutorialspoint.com:

CONNECT www.tutorialspoint.com HTTP/1.1


Kt ni c thnh lp vi Server v phn hi sau c gi tr li ti Client:

HTTP/1.1 200 Connection established

Date: Mon, 27 Jul 2009 12:28:53 GMT




Phng thc OPTIONS Phng thc OPTIONS c s dng bi Client tm ra cc phng thc HTTP v cc chc

nng c h tr bi mt Server. Client c th xc nh mt URL vi phng thc OPTIONS hoc

mt du * hng ti ton b Server. V d sau yu cu mt danh sch cc phng thc c

h tr bi mt Server ang chy trn tutorialspoint.com:

OPTIONS * HTTP/1.1


Server s gi mt thng tin da trn nh cu hnh hin ti ca Server, v d:

HTTP/1.1 200 OK

Date: Mon, 27 Jul 2009 12:28:53 GMT


Allow: GET,HEAD,POST,OPTIONS,TRACE

Content-Type: httpd/unix-directory

Phng thc TRACE Phng thc TRACE c s dng nh x cc ni dung ca mt yu cu HTTP ti ngi

yu cu m c th c s dng cho mc ch debug ti thi im ca s pht trin. V d sau ch

cch s dng ca phng thc TRACE:

TRACE / HTTP/1.1



Server s gi thng bo sau trong phn hi ti yu cu trn:

HTTP/1.1 200 OK

Date: Mon, 27 Jul 2009 12:28:53 GMT


Connection: close

Content-Type: message/http

Content-Length: 39

TRACE / HTTP/1.1





M ha trng thi trong HTTP Yu t Status-Code l mt s nguyn 3 k t, trong k t u tin ca m ha trng thi nh

ngha hng (loi) phn hi v hai k t cui khng c bt c vai tr phn loi no. C 5 gi tr ca

k t u tin:

STT M v miu t

1 1xx: Thng tin

N ngha l yu cu c nhn v tin trnh ang tip tc.

2 2xx: Thnh cng

N ngha l hot ng c nhn, c hiu, v c chp nhn mt

cch thnh cng.

3 3xx: S iu hng li

N ngha l hot ng phi c thc hin hon thnh yu cu.

4 4xx: Li Client

N ngha l yu cu cha c php khng chnh xc hoc khng c thc

hin.

5 5xx: Li Server

N ngha l Server tht bi vi vic thc hin mt yu cu nhn nh c v

kh thi.

Cc m trng thi l c tnh co dn v cc ng dng HTTP khng c yu cu hiu ngha

ca tt c cc m trng thi c ng k. Di y l mt danh sch lit k tt c cc m

trng thi:



1xx: Thng tin

Thng bo Miu t

100 Continue Ch mt phn ca yu cu c nhn bi Server, nhng

min l n khng b loi b, Client nn tip tc vi yu

cu.

101 Switching

Protocols

Server chuyn i giao thc.

2xx: Thnh cng

Thng bo Miu t

200 OK Yu cu l OK.

201 Created Yu cu l hon thnh, v mt ngun mi c to.

202 Accepted Yu cu c chp nhn cho x l, nhng vic x l

cha hon thnh.

203 Non-

authoritative

Information

Thng tin trong i tng Header l t mt bn sao ni

b hoc bn th 3, khng t Server ban u.

204 No Content Mt m trng thi v mt Header c cung cp trong

phn hi, nhng khng c phn thn i tng trong s

phn hi.

205 Reset Trnh duyt nn dn sch mu c s dng cho vic



Content truyn ti ny bi mt d liu u vo tng thm.

206 Partial

Content

Server ang tr li d liu cc b ca kch c c yu

cu. c s dng trong phn hi ti mt yu cu xc

nh mtRange Header. Server phi xc nh dy c

bao gm trong phn hi vi Content-Range header.

3xx: S iu hng li

Thng bo Miu t

300 Multiple

Choices

Mt danh sch cc link. Ngi s dng c th chn mt

link v ti v tr . Ti a 5 a ch.

301 Moved

Permanently

Trang c yu cu di chuyn ti mt URL mi.

302 Found Trang c yu cu di chuyn tm thi ti mt URL

mi.

303 See Other Trang c yu cu c th c tm di mt URL

khc.

304 Not

Modified

y l m phn hi ti mt If-Modified-Since hoc If-

None-Match header, ni m URL khng c chnh sa

t ngy c th.

305 Use Proxy URL c yu cu phi c truy cp thng qua mt s

y quyn c cp trong Location Header.



306 Unused M ny c s dng trong mt phin bn trc. N

khng cn c s dng na, nhng m ny c lu

gi.

307 Temporary

Redirect

Trang c yu cu di chuyn tm thi ti mt URL

mi.

4xx: Li Client

Thng bo Miu t

400 Bad Request Server khng hiu yu cu.

401 Unauthorized Trang c yu cu cn mt tn s dng v mt

mt khu.

402 Payment

Required

Bn khng th s dng m ny na..

403 Forbidden S truy cp ti trang c yu cu b cm.

404 Not Found Server khng th tm thy trang c yu cu.

405 Method Not

Allowed

Phng thc c xc nh trong yu cu l khng

c cho php.

406 Not Acceptable Server ch c th to mt phn hi m khng c

chp nhn bi Client.

407 Proxy

Authentication

Bn phi xc nhn vi mt Server y qun trc khi



Required yu cu ny c phc v.

408 Request

Timeout

Yu cu tn thi gian di hn thi gian Server c

chun b i.

409 Conflict Yu cu khng th c hon thnh bi v s xung

t.

410 Gone Trang c yu cu khng c sn na.

411 Length Required Content-Length khng c xc nh r. Server s

khng chp nhn yu cu m khng c n.

412 Precondition

Failed

iu kin trc c cung cp trong yu cu c

tnh ton l sai bi Server.

413 Request Entity

Too Large

Server s khng chp nhn yu cu, bi v i

tng yu cu l qu rng.

414 Request-url Too

Long

Server s khng chp nhn yu cu, bi v URL l

qu di. Xy ra khi bn chuyn mt yu cu port

ti mt yu cu get vi thng tin qu di.

415 Unsupported

Media Type

Server s khng chp nhn yu cu, bi v kiu

phng tin khng c h tr.

416 Requested

Range Not

Satisfiable

Dy byte c yu cu l khng c sn v bn

ngoi gii hn.



417 Expectation

Failed

Kh nng c cung cp trong mt trng Expect

khng th c kt ni bi Server.

5xx: Li Server

Thng bo Miu t

500 Internal Server

Error

Yu cu khng c hon thnh. Server bt gp

mt iu kin khng c mong i.

501 Not Implemented Yu cu khng c hon thnh. Server khng h

tr tnh nng c yu cu.

502 Bad Gateway Yu cu khng c hon thnh. Server nhn mt

phn hi khng c hiu lc t Server thng

ngun.

503 Service

Unavailable

Yu cu khng c hon thnh. Server tm thi

ang qu ti hoc down.

504 Gateway Timeout Gateway b tr.

505 HTTP Version

Not Supported

S

Cc trng Header trong HTTP Cc trng Header cung cp thng tin c yu cu v yu cu hoc phn hi, hoc v i tng

c gi trong phn thn thng bo. C 4 kiu ca Header thng bo HTTP:

Kiu chung (General-Header): Cc trng Header ny c kh nng ng dng chung cho

c cc thng bo yu cu v phn hi.



Kiu yu cu (Request-Header): Cc trng Header ny c kh nng ng dng ch cho

cc thng bo yu cu.

Kiu phn hi (Response-Header): Cc trng Header ny ch c kh nng p dng cho

cc thng bo phn hi.

Kiu thc th (Entity-Header): Cc trng ny xc nh thng tin v thn-thc th hoc,

nu khng c phn thn no hin th, v ngun c nhn din bi yu cu.

General Header Trng Cache-Control

Trng Header chung Cache-Control c s dng xc nh cc ch dn m PHI c tun

theo bi tt c cc h thng b nh n. C php nh sau:

Cache-Control : cache-request-directive|cache-response-directive

Mt Client hoc Server c th s dng Header chung Cache-Control xc nh cc tham s cho

b nh n hoc yu cu cc loi c th ca ti liu t b nh n. Cc ch dn b nh n c xc

nh trong mt danh sch c phn bit bi du phy. V d:

Cache-control: no-cache

Bng di lit k cc ch dn yu cu b nh n quan trng m c th c s dng

biClient trong yu cu HTTP ca n:

STT Ch dn yu cu b nh n v miu t

1 no-cache

Mt b nh n phi khng s dng phn hi lm tha mn mt yu cu

theo sau m khng ti xc nhn thnh cng vi Server ban u.

2 no-store

B nh n khng nn lu gi bt c th g v yu cu Client hoc phn

h Server.



3 max-age = giy (s)

Ch ra rng Client ang mun chp nhn mt phn hi m thi gian ca n

khng ln hn thi gian xc nh bng giy (s).

4 max-stale [ tnh bng giy ]

Ch ra rng Client ang mun chp nhn mt phn hi m vt thi

gian mn hn. Nu s giy c cung cp, n phi khng l ht hn bi

nhiu hn thi gian .

5 min-fresh = giy

Ch ra rng Client ang mun chp nhn mt phn hi m thi gian sng

khe ca n l khng t hn tui hin ti ca n cng vi thi gian xc

nh bng giy.

6 no-transform

Khng chuyn i phn thn i tng.

7 only-if-cached

Khng ly d liu mi. B nh n c th gi mt ti liu ch khi n trong

b nh n, v khng nn lin h vi Server ban u xem xt nu mt

bn sao mi hn tn ti.

Cc ch dn phn hi b nh n quan trng sau y c th c s dng bi Server trong phn

hi ca n:

STT Ch dn phn hi b nh n v Miu t

1 public

Ch ra rng phn hi c th c gi trong b nh n bi bt c b nh



n no.

2 private

Ch ra rng tt c hoc mt phn ca thng bo phn hi c xem nh l

cho mt ngi s dng n v phi khng c gi trong b nh n bi

mt b nh n c chia s.

3 no-cache

Mt b nh n phi khng s dng phn hi tha mn mt yu cu


4 no-store

B nh n khng nn lu bt c g v yu cu Client hoc phn hi

Server.

5 no-transform


6 must-revalidate

B nh n phi xc minh trng thi ca cc ti liu c trc khi s

dng n v cc ti liu mn hn khng nn c s dng.

7 proxy-revalidate

Ch dn ti xc nhn y quyn c cng ngha vi ch dn must-

revalidate, ngoi tr n khng p dng ti cc b nh n user agent khng

c chia s.

8 max-age = giy

Ch ra rng Client ang mun chp nhn mt yu cu m tui ca n



khng ln hn thi gian xc nh bng giy.

9 s-maxage = giy

Tui ti a c xc nh bi ch dn ny vt qu tui ti a xc nh

bi hoc ch dn max-age hoc Expires Header. Ch dn s-maxage lun

lun c b qua bi mt b nh c nhn.

Trng Connection

Trng Header chung Connection cho php ngi gi xc nh cc chc nng m c mong

c cho kt ni c th v phi khng c giao tip bi cc trm y nhim qua cc kt ni xa

hn. Di y l c php n gin cho s dng Connection Header:

Connection : "Connection"

HTTP/1.1 xc nh r chc nng kt ni close cho ngi gi ti tn hiu m kt ni s c ng

sau khi hon thnh phn hi. V d:

Connection: close

Theo mc nh, HTTP 1.1 s dng cc kt ni lin tc, ni m kt ni khng t ng ng sau khi

hon thnh mt giao dch. Trong khi , HTTP 1.0 khng c cc kt ni lin tc theo mc nh. Nu

mt Client 1.0 mong mun s dng cc kt ni lin tc, n s dng cc tham s keep-alvie nh

sau:

Connection: keep-alive

Trng Date

Tt c cc nhn Ngy/Thi gian PHI c biu din trong GMT, khng c trng hp ngoi tr.

Cc ng dng HTTP c cho php c s dng bt k 3 s biu din nhn Ngy/Thi gian no

sau y:

Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123

Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036

Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format

y, nh dng u tin l c s dng nhiu nht.



Trng Pragma

Trng Pragma c s dng bao gm cc ch dn c th thc hin m c th p dng ti

bt k ngi nhn no trong chui Yu cu/Phn hi. V d:

Pragma: no-cache

Ch dn ch xc nh r trong HTTP/1.0 l ch dn khng b nh n v c duy tr trong HTTP/1.1

cho tnh tng thch ngc v sau. Khng c cc ch dn Pragma mi s c nh ngha trong

tng lai.

Trng Trailer

Gi tr trng Trailer ch ra rng thit lp cho ca cc trng Header biu din trong trailer ca

mt thng bo c m ha vi m ha truyn ti c ng khi. Di y l c php ca

trng Trailer:

Trailer : field-name

Cc trng Header thng bo c lit k trong trng Trailer phi khng bao gm cc trng

Header sau:

Transfer-Encoding

Content-Length

Trailer

Trng Transfer-Encoding (M ha truyn ti)

Trng Transfer-Encoding ny ch ra kiu truyn ti no c p dng ti phn thn thng bo

cho vic truyn ti mt cch an ton gia ngi gi v ngi nhn. iu ny khng ging

nh Content-encoding bi v cc m ha truyn ti l mt thuc tnh ca thng bo, khng phi l

ca phn thn thng bo. C php ca trng Transfer-Encoding l nh sau:

Transfer-Encoding: chunked

Tt c cc gi tr Transfer-Encoding l khng nhy cm (khng phn bit hoa-thng).

Trng Upgrade

Trng Upgrade ny cho php Client xc nh nhng giao thc giao tip thm vo m n h tr v

s c s dng nu Server tm thy rng n thch hp chuyn i giao thc. V d:



Upgrade: HTTP/2.0, SHTTP/1.3, IRC/6.9, RTA/x11

Trng Upgrade c ch i cung cp mt k thut n gin cho truyn ti t HTTP/1.1 ti

mt s giao thc khng tng hp.

Trng Via

Trng Via phi c s dng bi cc gateway v cc trm y nhim ch ra cc giao thc

trung gian v ngi nhn. V d, mt thng bo yu cu c th c gi t mt HTTP/1.0 User

agent ti mt trm y nhim ni b c t tn m fred, m s dng HTTP/1.1 chuyn tip

yu cu ti mt trm y nhim cng cng ti nowhere.com, m hon thnh yu cu bi vic

chuyn tip n ti Server ban u ti www.ics.uci.edu. Yu cu c nhn bi www.ics.uci.edu s

c trng Via nh sau:

Via: 1.0 fred, 1.1 nowhere.com (Apache/1.1)

Trng Warning (Cnh bo)

Trng Warning c s dng mang thng tin thm v trng thi hoc s truyn ti ca mt

thng bo m c th khng c phn nh trong thng bo . Mt s phn hi c th mang

nhiu hn mt trng Warning.

Warning : warn-code SP warn-agent SP warn-text SP warn-date

Cc trng Header yu cu trn Client Trng Accept (Chp nhn)

Trng Accept ny c th c s dng xc nh cc kiu phng tin c th m l c th

chp nhn cho s phn hi. C php chung l nh sau:

Accept: type/subtype [q=qvalue]

Cc kiu phng tin c th c lit k phn bit nhau bi cc du phy v gi tr q ty biu

din mt mc cht lng c th chp nhn chp nhn cc kiu trn mt phm vi t 0 ti 1.

Di y l v d:

Accept: text/plain; q=0.5, text/html, text/x-dvi; q=0.8, text/x-c

on ny c th c bin dch nh text/html v text/x-c v l cc kiu phng tin c a

thch hn nhng nu chng khng tn ti, th sau gi i tng text/x-dvi , v nu n khng

tn ti, gi i tng text/plain.



Trng Accept-Charset

Trng ny c th c s dng ch cc b thit lp k t no c chp nhn cho s phn

hi. Di y l c php chung:

Accept-Charset: character_set [q=qvalue]

Nhiu b k t c th c lit k ring r nhau bi cc du phy v gi tr q ty biu din mt

mc cht lng c th chp nhn cho cc b k t khng c a thch hn trn mt min t

0 n 1. Di y l v d:

Accept-Charset: iso-8859-5, unicode-1-1; q=0.8

Gi tr c bit *, nu c trong trng Accept-Charset, kt ni mi b k t v nu khng c gi

tr trng Accept-Charset no, th mc nh l bt k b k t no cng c th c chp nhn.

Trng Accept-Encoding

Trng ny tng t nh Accept, nhng hn ch m ha ni dung l c th chp nhn trong phn

hi. C php chung l:

Accept-Encoding: encoding types

Cc v d l nh sau:

Accept-Encoding: compress, gzip

Accept-Encoding:

Accept-Encoding: *

Accept-Encoding: compress;q=0.5, gzip;q=1.0

Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0

Trng Accept-Language

Trng ny tng t nh Accept, nhng hn ch b thit lp ca cc ngn ng t nhin l c

a thch hn khi mt phn hi ti mt yu cu. C php chung l:

Accept-Language: language [q=qvalue]

Nhiu ngn ng c th c lit k phn bit nhau bi du phy v gi tr q ty biu din mt

mc cht lng c th chp nhn cho cc ngn ng khng c a thch hn trn min t 0

ti 1. Di y l mt v d:

Accept-Language: da, en-gb;q=0.8, en;q=0.7



Trng Authorization (S y quyn)

Gi tr trng Authorization bao gm cc s y nhim m cha thng tin y quyn ca mt user

agent cho phm vi ngun ang c yu cu. C php chung l:

Authorization : credentials

nh cu hnh HTTP/1.0 nh ngha gin y quyn C BN, ni m tham s y quyn l mt

chui ca tn s dng:mt khu c m ha trong c s 64 bit. Di y l v d:

Authorization: BASIC Z3Vlc3Q6Z3Vlc3QxMjM=

Gi tr gii m l guest:guest123, trong guest l ti khon ngi dng v guest123 l mt

khu.

Trng Cookie

Gi tr trng Cookie cha mt cp tn/gi tr ca thng tin c lu gi cho URL . Di y l

c php chung:

Cookie: name=value

Nhiu cookie c th c xc nh phn bit nhau bi cc du chm phy ; nh sau:

Cookie: name1=value1;name2=value2;name3=value3

Trng Expect

Trng Expect c s dng ch ra rng mt b thit lp c th ca cc hnh vi Server c

yu cu bi Client. C php chung l:

Expect : 100-continue | expectation-extension

Nu mt Server nhn mt yu cu cha mt trng Expect m bao gm mt dn mong i m

n khng h tr, n phi phn hi vi trng thi 417 (s mong i tht bi).

Trng From

Trng From cha mt a ch th in t cho ngi s dng m kim sot user agent. Di y

l mt c php n gin:

From: [email protected]

Trng ny c th c s dng cho nhp cc mc ch v nh l mt phng tin cho vic xc

nhn ngun ca cc yu cu khng kh thi hoc khng mun.



Trng Host

Trng Host c s dng xc nh Internet host v s hiu cng ca ngun c yu cu.

C php chung l:

Host : "Host" ":" host [ ":" port ] ;

Mt Host m khng c bt k thng tin port no ngy l port mc nh, m l 80. V d, mt yu

cu trn Server ban u cho http://w3.org/pub/WWW/ s l:

GET /pub/WWW/ HTTP/1.1

Host: www.w3.org

Trng If-Match

Trng If-Match c s dng trong mt method lm cho n c iu kin. Header ny yu cu

Server biu din method c yu cu ch khi gi tr c cung cp trong th ny kt ni vi

cc th i tng c cung cp c biu din bi Etag. C php chung l:

If-Match : entity-tag

Mt du (*) kt ni vi bt c i tng no, v s truyn ti tip tc ch khi i tng tn ti. Di

y l cc v d c th:

If-Match: "xyzzy"

If-Match: "xyzzy", "r2d2xxxx", "c3piozzzz"

If-Match: *

Nu khng c th i tng no kt ni, hoc nu (*) c cung cp v khng i tng hin ti

no tn ti, Server khng c trnh by method c yu cu, v phi tr li mt phn hi l 412

(iu kin trc tht bi).

Trng If-Modified-Since

Trng ny c s dng vi mt method lm cho n c iu kin. Nu URL c yu cu

khng c chnh sa t thi gian c xc nh trong trng ny, mt i tng s khng

c tr li t Server; thay vo , mt phn hi 304 (khng c chnh sa) s c tr li m

khng c bt c phn thn thng bo no. C php chung ca If-Modified-Since l:

If-Modified-Since : HTTP-date

Mt v d ca trng l:



If-Modified-Since: Sat, 29 Oct 1994 19:43:31 GMT

Nu khng c th i tng no kt ni vi, hoc nu * c cung cp v khng i tng hin

ti no tn ti,, Server khng c trnh by method c yu cu, v phi tr li phn hi 412

(iu kin trc tht bi).

Trng If-None-Match

Trng ny c s dng vi mt method lm cho n c iu kin. Trng ny yu cu Server

trnh by method c yu cu ch khi mt trong s gi tr cho ca th ny kt ni vi cc th

i tng c cung cp biu din bi Etag. C php chung l:

If-None-Match : entity-tag

Mt du * kt ni vi bt k i tng no, v s truyn ti tip tc ch khi i tng khng tn ti.

Di y l cc v d c th c:

If-None-Match: "xyzzy"

If-None-Match: "xyzzy", "r2d2xxxx", "c3piozzzz"

If-None-Match: *

Trng If-Range

Trng If-Range c th c s dng vi mt GET c iu kin yu cu ch mt phn ca i

tng m ang b tht lc, nu n khng c thay i, v ton b i tng nu n c thay

i. C php chung nh sau:

If-Range : entity-tag | HTTP-date

Hoc mt th i tng hoc mt d liu c th c s dng xc minh i tng ni b

nhn. V d:

If-Range: Sat, 29 Oct 1994 19:43:31 GMT

Ti y, nu ti liu khng c chnh sa t ngy cho, Server tr li dy byte c cung cp

bi trng Range, nu khng th n tr li tt c cc ti liu mi.

Trng If-Unmodified-Since

Trng ny c s dng vi mt method lm cho n c iu kin. C php chung l:

If-Unmodified-Since : HTTP-date



Nu ngun c yu cu khng c chnh sa t khi thi gian c xc nh trong trng

ny, Server s thc hin hot ng c yu cu nu nh If-Unmodified-Since khng biu din. V

d:

If-Unmodified-Since: Sat, 29 Oct 1994 19:43:31 GMT

Nu yu cu c kt qu l bt c g khc ngoi mt trng thi l 2xx hoc 4xx, th trng If-

Unmodified-Since nn c b qua.

Trng Max-Forwards

Trng ny cung cp mt k thut vi cc phng thc TRACE v OPTIONS gii hn s cc

trm y quyn hoc gateway m c th chuyn tip yu cu ti Server k tip. y l c php

chung:

Max-Forwards : n

Gi tr Max-Forward l mt s nguyn h thp phn ch rng s ln cn li ca thng bo yu cu

ny c th c chuyn tip. iu ny l hu ch cho debug vi phng thc TRACE, trnh c

cc vng lp v hn. V d:

Max-Forwards : 5

Trng ny c th b b qua vi tt c cc phng thc c nh ngha trong nh cu hnh

HTTP.

Trng Proxy-Authorization

Trng ny cho php Client xc nhn chnh n (hoc ngi s dng ca n) ti mt trm y

quyn m yu cu s y nhim. y l c php chung:

Proxy-Authorization : credentials

Gi tr trng Proxy-Authorization bao gm cc s y nhim cha thng tin y nhim ca user

agent cho trm y nhim v/hoc phm vi ca ngun c yu cu.

Trng Range

Trng Range xc nh dy ni b ca ni dung c yu cu t ti liu. C php chung l:

Range: bytes-unit=first-byte-pos "-" [last-byte-pos]

Gi tr First-byte-pos trong mt byte-range-spec chung cp byte-offset ca byte u tin trong mt

dy. Gi tr last-byte-pos cung cp byte-offset ca byte cui cng trong dy; l, cc v tr byte



c xc nh. Bn c th xc nh mt n v byte nh cc byte. Byte offset bt u ti 0. Mt s

v d n gin nh sau:

- The first 500 bytes

Range: bytes=0-499

- The second 500 bytes

Range: bytes=500-999

- The final 500 bytes

Range: bytes=-500

- The first and last bytes only

Range: bytes=0-0,-1

Nhiu dy c th c lit k, phn bit nhau bi du phy. Nu k s u tin trong dy byte

phn bit nhau bi du phy b b qun, dy c gi s l tnh ton t phn cui ca ti liu. Nu

k s th hai b b qun, dy l byte th n ti phn cui ti liu.

Trng Referer

Trng ny cho php Client xc nh a ch URI ca ngun m t URL c yu cu. C

php chung l nh sau:

Referer : absoluteURI | relativeURI

Di y l v d:

Referer: http://www.tutorialspoint.org../http/index.jsp

Nu gi tr trng l mt URI quan h, n nn c phin dch lin quan ti Request-URI.

Trng TE

Trng ny ch s m rng no m transfer-coding ang mun chp nhn trong phn hi v c

hoc khng n ang mun chp nhn cc trng trailer trong mt transfer-codingc ng khi.

Sau y l c php chung:

TE : t-codings

S hin din ca t kha trailers ch rng Client ang mun chp nhn cc trng trailer trong

mt transfer-coding c ng khi v n c xc nh theo mt trong 2 cch:



TE: deflate

TE:

TE: trailers, deflate;q=0.5

Nu gi tr trng TE l trng hoc khng trng TE no hin din, th khi ch c transfer-

coding c ng khi (chunked). Mt thng bo vi khng transfer-coding l lun lun c th

chp nhn.

Trng User-Agent

Trng User-Agent cha thng tin v tc nhn ngi s dng to yu cu. Sau y l c php

chung:

User-Agent : product | comment

V d:


Cc trng Phn hi t Server Trng Accept-Ranges

Trng ny cho php Server ch s chp nhn ca n v cc dy yu cu cho mt ngun. C

php chung l:

Accept-Ranges : range-unit | none

V d, mt Server m chp nhn cc yu cu v dy byte c th gi:


Server m khng chp nhn bt k loi dy yu cu cho mt ngun c th gi:

Accept-Ranges: none

iu ny s khuyn Client khng c gng chim c mt dy yu cu.

Trng Age

Trng Age chuyn tnh ton v s lng thi gian t khi phn hi c to ra ti Server ban u

ca ngi gi. C php chung l:

Age : delta-seconds



Gi tr Age l cc s nguyn thp phn khng ph nh, biu din thi gian bng giy. Sau y l

mt v d n gin:

Age: 1030

Mt HTTP/1.1 Server m bao gm mt b nh n phi bao gm mt trng Age trong mi phn

hi c to t b nh n ring ca n.

Trng ETag

Trng Etag cung cp gi tr hin ti ca th i tng cho bin th c yu cu. C php chung

l:

ETag : entity-tag

Di y l mt s v d n gin:

ETag: "xyzzy"

ETag: W/"xyzzy"

ETag: ""

Trng Location

Trng Location c s dng iu hng li ngi nhn ti mt v tr khc ngoi Reqest-

URI. C php chung l:

Location : absoluteURI

Di y l mt v d n gin:

Location: http://www.tutorialspoint.org../http/index.jsp

Trng Content-Location khc Location trong m Content-Location xc nhn v tr ban u

ca i tng c bao gm trong yu cu.

Trng Proxy-Authenticate

Trng ny phi c bao gm nh l mt phn ca phn hi 407. C php chung l:

Proxy-Authenticate : challenge



Trng Retry-After

Trng ny c th c s dng vi mt phn hi 503 (Service Unavailable - dch v khng c

sn) ch rng dch v c mong i l khng c sn trong vng bao lu ti Client ang yu

cu. C php chung l:

Retry-After : HTTP-date | delta-seconds

Cc v d:

Retry-After: Fri, 31 Dec 1999 23:59:59 GMT

Retry-After: 120

Trong v d sau, s tr hon l 2 pht.

Trng Server

Trng ny cha thng tin v phn mm c s dng bi Server ban u kim sot yu cu.

C php chung l:

Server : product | comment

Sau y l v d:


Nu phn hi ang c chuyn tip qua mt trm y quyn, ng dng y quyn khng c

chnh sa trng Server.

Trng Set-Cookie

Trng ny cha mt cp tn/gi tr ca thng tin gi li cho URL. C php chung l:

Set-Cookie: NAME=VALUE; OPTIONS

Trng phn hi Set-Cookie bao gm Set-Cookie du hiu, c theo sau bi mt danh sch

c phn bit bng du phy ca mt hoc nhiu cookie. y l cc gi tr c th m bn c

th xc nh nh l cc tnh nng:

STT Cc tnh nng v Miu t

1 Comment=comment



Tnh nng ny c th c s dng xc nh bt c li bnh no lin

kt vi cookie.

2 Domain=domain

Thuc tnh Domain xc nh min m vi n cookie l c hiu lc.

3 Expires=Date-time

Ngy m cookie s ht hn. Nu n l trng, cookie s ht hn khi khch

s dng ri khi trnh duyt.

4 Path=path

Thuc tnh path xc nh b thit lp ph ca cc URL m cookie ny p

dng.

5 Secure

N ch dn user agent tr li cookie ch di dng mt kt ni an

ton.

Sau y l mt v d ca mt cookie n gin c to bi Server:

Set-Cookie: name1=value1,name2=value2; Expires=Wed, 09 Jun 2021 10:18:14 GMT

Trng Vary

Trng Vary xc nh rng i tng c nhiu ngun v v th c th theo nhiu cch ti mt

danh sch yu cu c xc nh. Sau y l c php chung:

Vary : field-name

Bn c th xc nh nhiu Header phn bit nhau bi du phy v mt gi tr l du * m khng

xc nh cc tham s (khng gii hn ti cc Header yu cu). Sau y l v d n gin:

Vary: Accept-Language, Accept-Encoding

y, cc tn trng l khng nhy cm.



Trng WWW-Authenticate

Trng ny phi c bao gm trong cc thng bo phn hi 401 (khng c y quyn). Gi tr

trng bao gm t nht mt challenge (hiu lnh) m ch dn gin y quyn v cc tham s c

th p dng ti URI yu cu. C php chung l:

WWW-Authenticate : challenge

Gi tr tng c th cha nhiu hn mt challenge, hoc nu nhiu hn mt trng WWW-

Authenticate c cung cp, cc ni dung ca chnh challenge c th cha mt danh sch

c phn bit bi du phy ca cc tham s y quyn. Sau y l mt v d n gin:

WWW-Authenticate: BASIC realm="Admin"

Entity Headers Trng Allow

Trng ny lit k b thit lp ca cc method c h tr bi ngun c xc nhn bi Request-

URI. C php chung l:

Allow : Method

Bn c th xc nh nhiu phng thc c phn bit bi du phy. Sau y l mt v d n

gin:

Allow: GET, HEAD, PUT

Trng ny khng ngn cn mt Client t vic c gng th cc method khc.

Trng Content-Encoding

Trng ny c s dng nh mt b chnh sa ti kiu phng tin. C php chung l:

Content-Encoding : content-coding

M ha ni dung l mt thuc tnh ca mt i tng c xc nh bi Request-URI. Sau y l

mt v d n gin:

Content-Encoding: gzip

Nu m ha ni dung ca mt i tng l mt thng bo yu cu l khng c chp nhn bi

Server ngun, Server s phn hi vi mt m trng thi 415 (kiu phng tin khng c h tr).



Trng Content-Language

Trng ny miu t cc ngn ng t nhin ca ngi c d nh cho i tng bao gm.

Sau y l c php chung:

Content-Language : language-tag

Nhiu ngn ng c th c lit k cho ni dung m c d nh cho nhiu ngi c. Sau y

l mt v d n gin:

Content-Language: mi, en

Mc ch u tin ca Content-Language l cho php mt ngi s dng xc nhn v to

s khc bit cc i tng theo ngn ng c a thch hn ca ring ngi dng.

Trng Content-Length

Trng ny ch dn kch c ca phn thn i tng, trong s thp phn ca h 8, c gi ti

ngi nhn hoc, trong trng hp ca phng thc HEAD, kch c ca phn thn i tng m

s c gi, c yu cu l mt GET. C php chung l:

Content-Length : DIGITS

Sau y l mt v d n gin:

Content-Length: 3495

Bt k Conten-Length no ln hn hoc bng l mt gi tr c hiu lc.

Trng Content-Location

Trng ny c th c s dng cung cp v tr ngun cho i tng c bao gm trong

thng bo khi i tng l c th truy cp t mt v tr ring bit t mt URI ca ngun c

yu cu. C php chung l:

Content-Location: absoluteURI | relativeURI


Content-Location: http://www.tutorialspoint.org../http/index.jsp

Gi tr ca Content-Location cng nh ngha URI c s cho i tng.



Trng Content-MD5

Trng ny c th c s dng cung cp mt h thng phn loi MD5 ca i tng cho vic

kim tra tnh nguyn vn ca thng tin ti ngi nhn. C php chung l:

Content-MD5 : md5-digest using base64 of 128 bit MD5 digest as per RFC 1864


Content-MD5 : 8c2d46911f3f5a326455f0ed7a8ed3b3

H thng phn loi MD5 c tnh ton ha da trn c s ni dung ca phn thn thc th, bao

gm bt c m ha ni dung no m c p dng, nhng khng bao gm bt c m ha

truyn ti c p dng ti phn thn thng bo.

Trng Content-Range

Trng ny c gi vi mt phn thn thc th ni b xc nh ni trong ton b phn thn

i tng m phn thn ni b nn c p dng. C php chung l:

Content-Range : bytes-unit SP first-byte-pos "-" last-byte-pos

Cc v d ca cc gi tr byte-content-range-spec, gi s rng i tng cha mt tng ca 1234

byte:

- The first 500 bytes:

Content-Range : bytes 0-499/1234

- The second 500 bytes:


- All except for the first 500 bytes:


- The last 500 bytes:


Khi mt thng bo HTTP bao gm ni dung ca mt dy n, ni dung ny c truyn ti vi mt

Content-Range, v mt Content-Length ch s byte c truyn ti thc s. V d:

HTTP/1.1 206 Partial content

Date: Wed, 15 Nov 1995 06:25:24 GMT



Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT

Content-Range: bytes 21010-47021/47022

Content-Length: 26012

Content-Type: image/gif

Trng Content-Type

Trng ny ch dn kiu phng tin ca phn thn i tng c gi ti ngi nhn hoc,

trong trng hp phng thc HEAD, kiu phng tin m s c gi, c yu cu l GET. C

php chung l:

Content-Type : media-type

Sau y l mt v d:

Content-Type: text/html; charset=ISO-8859-4

Trng Expires

Trng ny cung cp Ngy/Thi gian sau phn hi c cho l ht hn. C php chung:

Expires : HTTP-date

Sau y l mt v d:

Expires: Thu, 01 Dec 1994 16:00:00 GMT

Trng Last-Modified

Trng ny ch ngy v thi gian ti Server ban u tin rng s bin i c chnh sa ln

cui. C php chung l:

Last-Modified: HTTP-date

Sau y l mt v d:

Last-Modified: Tue, 15 Nov 1994 12:45:26 GMT

Caching trong HTTP HTTP c s dng mt cch c trng cho cc h thng thng tin c phn phi, ni m hiu

sut c th c nng cao bi s dng cc b nh n phn hi. Giao thc HTTP/1.1 bao gm mt

s cc yu t c d nh thc hin cc cng vic lu vo b nh n.



Mc tiu ca lu vo b nh n trong HTTP/1.1 l tnh ton s cn thit gi cc yu cu

trong nhiu trng hp, v tnh ton s cn thit gi cc s phn hi y trong nhiu

trng hp khc.

K thut b nh n c s trong HTTP/1.1 l gm cc ch th ti cc b nh n ni m Server xc

nh thi gian v ngy mn hn. Chng ta s dng trng Cache-Control cho mc ch ny.

Trng Cache-Control cho php mt Client hoc Server truyn cc ch th a dng trong hoc

cc yu cu hoc cc s phn hi. Nhng ch th ny c c trng l c quyn u tin cao hn cc

thut ton lu vo b nh n theo mc nh. Cc ch th lu vo b nh n c xc nh trong

mt danh sch phn bit nhau bi du phy. V d:

Cache-control: no-cache

Sau y l cc ch th yu cu b nh n c th c s dng bi Client trong yu cu HTTP ca

n:

STT Ch dn yu cu b nh n v miu t

1 no-cache

Mt b nh n phi khng s dng phn hi lm tha mn mt yu cu


2 no-store

B nh n khng nn lu gi bt c th g v yu cu Client hoc phn h

Server.

3 max-age = (tnh bng giy)

Ch ra rng Client ang mun chp nhn mt phn hi m thi gian ca n

khng ln hn thi gian xc nh bng giy (s).

4 max-stale [= giy]

Ch ra rng Client ang mun chp nhn mt phn hi m vt thi

gian mn hn. Nu s giy c cung cp, n phi khng l ht hn bi

nhiu hn thi gian .



5 min-fresh = giy

Ch ra rng Client ang mun chp nhn mt phn hi m thi gian sng

khe ca n l khng t hn tui hin ti ca n cng vi thi gian xc

nh bng giy.

6 no-transform


7 only-if-cached

Khng ly d liu mi. B nh n c th gi mt ti liu ch khi n trong

b nh n, v khng nn lin h vi Server ban u xem xt nu mt

bn sao mi hn tn ti.

Cc ch th phn hi b nh n sau y c th c s dng bi Server trong phn hi HTTP ca

n:

STT Ch dn phn hi b nh n v Miu t

1 public

Ch ra rng phn hi c th c gi trong b nh n bi bt c b nh

n no.

2 private

Ch ra rng tt c hoc mt phn ca thng bo phn hi c xem nh l

cho mt ngi s dng n v phi khng c gi trong b nh n bi

mt b nh n c chia s.

3 no-cache

Mt b nh n phi khng s dng phn hi tha mn mt yu cu


4 no-store

B nh n khng nn lu bt c g v yu cu Client hoc phn hi



Server.

5 no-transform


6 must-revalidate

B nh n phi xc minh trng thi ca cc ti liu c trc khi s dng

n v cc ti liu mn hn khng nn c s dng.

7 proxy-revalidate

Ch dn ti xc nhn y quyn c cng ngha vi ch dn must-revalidate,

ngoi tr n khng p dng ti cc b nh n user agent khng c chia

s..

8 max-age = giy

Ch ra rng Client ang mun chp nhn mt yu cu m tui ca n

khng ln hn thi gian xc nh bng giy.

9 s-maxage = giy

Tui ti a c xc nh bi ch dn ny vt qu tui ti a xc nh

bi hoc ch dn max-age hoc Expires Header. Ch dn s-maxage lun

lun c b qua bi mt b nh c nhn.

M ha URL trong HTTP Cc HTTP URL c th ch c gi thng qua Internet bi s dng b k t ASCII, m thng

cha cc k t bn ngoi b k t ASCII. V th cc k t khng an ton phi c i ch vi

a % c theo sau bi hai k s h thp lc phn.

Bng di y ch cc k hiu ASCII ca cc k t v s thay th ca chng m c th c s

dng trong URL trc khi truyn n ti Server.

ASCII Biu tng

S thay th



< 32 M ha vi %xx, vi xx l s i din trong h thp lc phn ca k t.

32 space + or %20

33 ! %21

34 " %22

35 # %23

36 $ %24

37 % %25

38 & %26

39 ' %27

40 ( %28

41 ) %29

42 * *

43 + %2B

44 , %2C

45 - -



46 . .

47 / %2F

48 0 0

49 1 1

50 2 2

51 3 3

52 4 4

53 5 5

54 6 6

55 7 7

56 8 8

57 9 9

58 : %3A

59 ; %3B

60 < %3C



61 = %3D

62 > %3E

63 ? %3F

64 @ %40

65 A A

66 B B

67 C C

68 D D

69 E E

70 F F

71 G G

72 H H

73 I I

74 J J

75 K K



76 L L

77 M M

78 N N

79 O O

80 P P

81 Q Q

82 R R

83 S S

84 T T

85 U U

86 V V

87 W W

88 X X

89 Y Y

90 Z Z



91 [ %5B

92 \ %5C

93 ] %5D

94 ^ %5E

95 _ _

96 ` %60

97 a a

98 b b

99 c c

100 d d

101 e e

102 f f

103 g g

104 h h

105 i i



106 j j

107 k k

108 l l

109 m m

110 n n

111 o o

112 p p

113 q q

114 r r

115 s s

116 t t

117 u u

118 v v

119 w w

120 x x



121 y y

122 z z

123 { %7B

124 | %7C

125 } %7D

126 ~ %7E

127 %7F

> 127 M ha vi %xx, vi xx l s i din trong h thp lc phn ca k t.

Bo mt trong HTTP HTTP c s dng cho giao tip thng tin qua Internet, v th cc nh lp trnh ng dng, cc

nh cung cp thng tin, v nhng ngi s dng nn nhn bit cc gii hn bo v trong

HTTP/1.1. Chng tho lun ny s khng bao gm cc gii php r rng ti nhng vn c

cp ti y, nhng n a ra mt s gi gim cc ri ro.

S r r thng tin c nhn

Documents

Tài Liệu HTTP Tiếng Việt