网络热词 > MIME

MIME

MIME(Multipurpose Internet Mail Extensions)多用途互联网邮件扩展类型。是设定某种扩展名的文件用一种应用程序来打开的方式类型,当该扩展名文件被访问的时候,浏览器会自动使用指定应用程序来打开。多用于指定一些客户端自定义的文件名,以及一些媒体文件打开方式。

它是一个互联网标准,扩展了电子邮件标准,使其能够支持:

非ASCII字符文本;非文本格式附件(二进制、声音、图像等);由多部分(multiple parts)组成的消息体;包含非ASCII字符的头信息(Header information)。

这个标准被定义在RFC 2045、RFC 2046、RFC 2047、RFC 2048、RFC 2049等RFC中。 MIME改善了由RFC 822转变而来的RFC 2822,这些旧标准规定电子邮件标准并不允许在邮件消息中使用7位ASCII字符集以外的字符。正因如此,一些非英语字符消息和二进制文件,图像,声音等非文字消息原本都不能在电子邮件中传输(MIME可以)。MIME规定了用于表示各种各样的数据类型的符号化方法。 此外,在万维网中使用的HTTP协议中也使用了MIME的框架,标准被扩展为互联网媒体类型。

MIME 是multipurpose Internet mail extensions 的缩写。

它是一种协议,可使电子邮件除包含一般纯文本以外,还可加上彩色图片、视频、声音或二进位格式的文件。

它要求邮件的发送端和接收端必须有解读MIME 协议的电子邮件程序。

MIME的英文全称是"Multipurpose Internet Mail Extensions" 多功能Internet 邮件扩充服务,它是一种多用途网际邮件扩充协议,在1992年最早应用于电子邮件系统,但后来也应用到浏览器服务器会将它们发送的多媒体数据的类型告诉浏览器,而通知手段就是说明该多媒体数据的MIME类型,从而让浏览器知道接收到的信息哪些是MP3文件,哪些是Shockwave文件等等。服务器将MIME标志符放入传送的数据中来告诉浏览器使用哪种插件读取相关文件。

MIME能够支持非ASCII字符、二进制格式附件等多种格式的邮件消息。这个标准被定义在; RFC 2045,; RFC 2046,; RFC 2047,; RFC 2048,; RFC 2049等RFC中。 由RFC 822转变而来的RFC 2822,规定电子邮件标准并不允许在邮件消息中使用7位ASCII字符集以外的字符。正因如此,一些非英语字符消息和二进制文件,图像,声音等非文字消息都不能在电子邮件中传输。MIME规定了用于表示各种各样的数据类型的符号化方法。

浏览器接收到文件后,会进入插件系统进行查找,查找出哪种插件可以识别读取接收到的文件。如果浏览器不清楚调用哪种插件系统,它可能会告诉用户缺少某插件,或者直接选择某现有插件来试图读取接收到的文件,后者可能会导致系统的崩溃。传输的信息中缺少MIME标识可能导致的情况很难估计,因为某些计算机系统可能不会出现什么故障,但某些计算机可能就会因此而崩溃。

检查一个服务器是否正确设置了MIME类型的步骤是:

1. 在Netscape浏览器中打开服务器网页,

2. 进入"View"菜单,选择"Page Info",

3. 在弹出的窗口中点击上层框架中的"EMBED",

4. 在下层框架中查看MIME的类型是否为"application/x-director"或"application/x-shockwave-flash",如果是上述信息的话表明服务器已经正确设置了MIME类型;而如果MIME类型列出的是文本内容、八位一组的数据或是其它形式均表明服务器的MIME类型没有设置正确。

如果服务器没有正确标明其发送的数据的类型,服务器管理员应该正确添加相关信息,具体操作方法非常简单快捷。

Microsoft公司应用于Windows系统下的浏览器使用ActiveX控件,而不是Netscape插件,这种浏览器不必象其它浏览器那样依靠MIME的编码。"OBJECT"标签的"CLSID"属性准确地标明了应调用哪种程序来读取接收到的文件,因此浏览器不必象"EMBED"标签那样选择一种读取程序。正因为如此,你往往会在使用带插件的浏览器时遇到MIME问题,而使用ActiveX控件的浏览器则很少出现此类麻烦。

正由于上述工作方式的差别也解释了一种现象,不知你是否发现在使用Netscape浏览器播放WAV文件时,浏览器会调用LiveConnect插件进行播放,而其它浏览器一般都使用通用的QuickTime的播放插件等来进行播放,这是因为Netscape浏览器接收文件需要读取MIME标识符,以便决定调用哪种程序来读取接收的文件,而服务器设置在Netscape浏览器中播放WAV文件应使用LiveConnect插件,因此Netscape浏览器接收到WAV格式的文件时必然就会调用LiveConnect插件,但由于其它浏览器不使用这种方式,因此它们都使用系统默认的播放WAV格式文件的播放器。当然Flash电影文件并不存在这种问题,因为只有Flash播放器才能够正确读取这种格式的文件。

在把输出结果传送到浏览器上的时候,浏览器必须启动适当的应用程序来处理这个输出文档。这可以通过多种类型MIME(多功能网际邮件扩充协议)来完成。在HTTP中,MIME类型被定义在Content-Type header中。

例如,假设你要传送一个Microsoft Excel文件到客户端。那么这时的MIME类型就是“application/vnd.ms-excel”。在大多数实际情况中,这个文件然后将传送给Excel来处理(假设我们设定Excel为处理特殊MIME类型的应用程序)。在ASP中,设定MIME类型的方法是通过Response对象的ContentType属性。

格式前面为后辍名,后面为对应的MIME型(例如:rar application/x-rar-compressed 表示.RAR对应的是application/x-rar-compressed )

application/vnd.lotus-1-2-3

3gp video/3gpp

aab application/x-authoware-bin

aam application/x-authoware-map

aas application/x-authoware-seg

ai application/postscript

aif audio/x-aiff

aifc audio/x-aiff

aiff audio/x-aiff

als audio/X-Alpha5

amc application/x-mpeg

ani application/octet-stream

asc text/plain

asd application/astound

asf video/x-ms-asf

asn application/astound

asp application/x-asap

asx video/x-ms-asf

au audio/basic

avb application/octet-stream

avi video/x-msvideo

awb audio/amr-wb

bcpio application/x-bcpio

bin application/octet-stream

bld application/bld

bld2 application/bld2

bmp application/x-MS-bmp

bpk application/octet-stream

bz2 application/x-bzip2

cal image/x-cals

ccn application/x-cnc

cco application/x-cocoa

cdf application/x-netcdf

cgi magnus-internal/cgi

chat application/x-chat

class application/octet-stream

clp application/x-msclip

cmx application/x-cmx

co application/x-cult3d-object

cod image/cis-cod

cpio application/x-cpio

cpt application/mac-compactpro

crd application/x-mscardfile

csh application/x-csh

csm chemical/x-csml

csml chemical/x-csml

css text/css

cur application/octet-stream

dcm x-lml/x-evm

dcr application/x-director

dcx image/x-dcx

dhtml text/html

dir application/x-director

dll application/octet-stream

dmg application/octet-stream

dms application/octet-stream

doc application/msword

dot application/x-dot

dvi application/x-dvi

dwf drawing/x-dwf

dwg application/x-autocad

dxf application/x-autocad

dxr application/x-director

ebk application/x-expandedbook

emb chemical/x-embl-dl-nucleotide

embl chemical/x-embl-dl-nucleotide

eps application/postscript

epub application/epub+zip

eri image/x-eri

es audio/echospeech

esl audio/echospeech

etc application/x-earthtime

etx text/x-setext

evm x-lml/x-evm

evy application/x-envoy

exe application/octet-stream

fh4 image/x-freehand

fh5 image/x-freehand

fhc image/x-freehand

fif image/fif

fm application/x-maker

fpx image/x-fpx

fvi video/isivideo

gau chemical/x-gaussian-input

gca application/x-gca-compressed

gdb x-lml/x-gdb

gif image/gif

gps application/x-gps

gtar application/x-gtar

gz application/x-gzip

hdf application/x-hdf

hdm text/x-hdml

hdml text/x-hdml

hlp application/winhlp

hqx application/mac-binhex40

htm text/html

html text/html

hts text/html

ice x-conference/x-cooltalk

ico application/octet-stream

ief image/ief

ifm image/gif

ifs image/ifs

imy audio/melody

ins application/x-NET-Install

ips application/x-ipscript

ipx application/x-ipix

it audio/x-mod

itz audio/x-mod

ivr i-world/i-vrml

j2k image/j2k

jad text/vnd.sun.j2me.app-descriptor

jam application/x-jam

jar application/java-archive

jnlp application/x-java-jnlp-file

jpe image/jpeg

jpeg image/jpeg

jpg image/jpeg

jpz image/jpeg

js application/x-javascript

jwc application/jwc

kjx application/x-kjx

lak x-lml/x-lak

latex application/x-latex

lcc application/fastman

lcl application/x-digitalloca

lcr application/x-digitalloca

lgh application/lgh

lha application/octet-stream

lml x-lml/x-lml

lmlpack x-lml/x-lmlpack

lsf video/x-ms-asf

lsx video/x-ms-asf

lzh application/x-lzh

m13 application/x-msmediaview

m14 application/x-msmediaview

m15 audio/x-mod

m3u audio/x-mpegurl

m3url audio/x-mpegurl

ma1 audio/ma1

ma2 audio/ma2

ma3 audio/ma3

ma5 audio/ma5

man application/x-troff-man

map magnus-internal/imagemap

mbd application/mbedlet

mct application/x-mascot

mdb application/x-msaccess

mdz audio/x-mod

me application/x-troff-me

mel text/x-vmel

mi application/x-mif

mid audio/midi

midi audio/midi

mif application/x-mif

mil image/x-cals

mio audio/x-mio

mmf application/x-skt-lbs

mng video/x-mng

mny application/x-msmoney

moc application/x-mocha

mocha application/x-mocha

mod audio/x-mod

mof application/x-yumekara

mol chemical/x-mdl-molfile

mop chemical/x-mopac-input

mov video/quicktime

movie video/x-sgi-movie

mp2 audio/x-mpeg

mp3 audio/x-mpeg

mp4 video/mp4

mpc application/vnd.mpohun.certificate

mpe video/mpeg

mpeg video/mpeg

mpg video/mpeg

mpg4 video/mp4

mpga audio/mpeg

mpn application/vnd.mophun.application

mpp application/vnd.ms-project

mps application/x-mapserver

mrl text/x-mrml

mrm application/x-mrm

ms application/x-troff-ms

mts application/metastream

mtx application/metastream

mtz application/metastream

mzv application/metastream

nar application/zip

nbmp image/nbmp

nc application/x-netcdf

ndb x-lml/x-ndb

ndwn application/ndwn

nif application/x-nif

nmz application/x-scream

nokia-op-logo image/vnd.nok-oplogo-color

npx application/x-netfpx

nsnd audio/nsnd

nva application/x-neva1

oda application/oda

oom application/x-AtlasMate-Plugin

pac audio/x-pac

pae audio/x-epac

pan application/x-pan

pbm image/x-portable-bitmap

pcx image/x-pcx

pda image/x-pda

pdb chemical/x-pdb

pdf application/pdf

pfr application/font-tdpfr

pgm image/x-portable-graymap

pict image/x-pict

pm application/x-perl

pmd application/x-pmd

png image/png

pnm image/x-portable-anymap

pnz image/png

pot application/vnd.ms-powerpoint

ppm image/x-portable-pixmap

pps application/vnd.ms-powerpoint

ppt application/vnd.ms-powerpoint

pqf application/x-cprplayer

pqi application/cprplayer

prc application/x-prc

proxy application/x-ns-proxy-autoconfig

ps application/postscript

ptlk application/listenup

pub application/x-mspublisher

pvx video/x-pv-pvx

qcp audio/vnd.qcelp

qt video/quicktime

qti image/x-quicktime

qtif image/x-quicktime

r3t text/vnd.rn-realtext3d

ra audio/x-pn-realaudio

ram audio/x-pn-realaudio

rar application/octet-stream

ras image/x-cmu-raster

rdf application/rdf+xml

rf image/vnd.rn-realflash

rgb image/x-rgb

rlf application/x-richlink

rm audio/x-pn-realaudio

rmf audio/x-rmf

rmm audio/x-pn-realaudio

rmvb audio/x-pn-realaudio

rnx application/vnd.rn-realplayer

roff application/x-troff

rp image/vnd.rn-realpix

rpm audio/x-pn-realaudio-plugin

rt text/vnd.rn-realtext

rte x-lml/x-gps

rtf application/rtf

rtg application/metastream

rtx text/richtext

rv video/vnd.rn-realvideo

rwc application/x-rogerwilco

s3m audio/x-mod

s3z audio/x-mod

sca application/x-supercard

scd application/x-msschedule

sdf application/e-score

sea application/x-stuffit

sgm text/x-sgml

sgml text/x-sgml

sh application/x-sh

shar application/x-shar

shtml magnus-internal/parsed-html

shw application/presentations

si6 image/si6

si7 image/vnd.stiwap.sis

si9 image/vnd.lgtwap.sis

sis application/vnd.symbian.install

sit application/x-stuffit

skd application/x-Koan

skm application/x-Koan

skp application/x-Koan

skt application/x-Koan

slc application/x-salsa

smd audio/x-smd

smi application/smil

smil application/smil

smp application/studiom

smz audio/x-smd

snd audio/basic

spc text/x-speech

spl application/futuresplash

spr application/x-sprite

sprite application/x-sprite

sdp application/sdp

spt application/x-spt

src application/x-wais-source

stk application/hyperstudio

stm audio/x-mod

sv4cpio application/x-sv4cpio

sv4crc application/x-sv4crc

svf image/vnd

svg image/svg-xml

svh image/svh

svr x-world/x-svr

swf application/x-shockwave-flash

swfl application/x-shockwave-flash

t application/x-troff

tad application/octet-stream

talk text/x-speech

tar application/x-tar

taz application/x-tar

tbp application/x-timbuktu

tbt application/x-timbuktu

tcl application/x-tcl

tex application/x-tex

texi application/x-texinfo

texinfo application/x-texinfo

tgz application/x-tar

thm application/vnd.eri.thm

tif image/tiff

tiff image/tiff

tki application/x-tkined

tkined application/x-tkined

toc application/toc

toy image/toy

tr application/x-troff

trk x-lml/x-gps

trm application/x-msterminal

tsi audio/tsplayer

tsp application/dsptype

tsv text/tab-separated-values

ttf application/octet-stream

ttz application/t-time

txt text/plain

ult audio/x-mod

ustar application/x-ustar

uu application/x-uuencode

uue application/x-uuencode

vcd application/x-cdlink

vcf text/x-vcard

vdo video/vdo

vib audio/vib

viv video/vivo

vivo video/vivo

vmd application/vocaltec-media-desc

vmf application/vocaltec-media-file

vmi application/x-dreamcast-vms-info

vms application/x-dreamcast-vms

vox audio/voxware

vqe audio/x-twinvq-plugin

vqf audio/x-twinvq

vql audio/x-twinvq

vre x-world/x-vream

vrml x-world/x-vrml

vrt x-world/x-vrt

vrw x-world/x-vream

vts workbook/formulaone

wav audio/x-wav

wax audio/x-ms-wax

wbmp image/vnd.wap.wbmp

web application/vnd.xara

wi image/wavelet

wis application/x-InstallShield

wm video/x-ms-wm

wma audio/x-ms-wma

wmd application/x-ms-wmd

wmf application/x-msmetafile

wml text/vnd.wap.wml

wmlc application/vnd.wap.wmlc

wmls text/vnd.wap.wmlscript

wmlsc application/vnd.wap.wmlscriptc

wmlscript text/vnd.wap.wmlscript

wmv video/x-ms-wmv

wmx video/x-ms-wmx

wmz application/x-ms-wmz

wpng image/x-up-wpng

wpt x-lml/x-gps

wri application/x-mswrite

wrl x-world/x-vrml

wrz x-world/x-vrml

ws text/vnd.wap.wmlscript

wsc application/vnd.wap.wmlscriptc

wv video/wavelet

wvx video/x-ms-wvx

wxl application/x-wxl

x-gzip application/x-gzip

xar application/vnd.xara

xbm image/x-xbitmap

xdm application/x-xdma

xdma application/x-xdma

xdw application/vnd.fujixerox.docuworks

xht application/xhtml+xml

xhtm application/xhtml+xml

xhtml application/xhtml+xml

xla application/vnd.ms-excel

xlc application/vnd.ms-excel

xll application/x-excel

xlm application/vnd.ms-excel

xls application/vnd.ms-excel

xlt application/vnd.ms-excel

xlw application/vnd.ms-excel

xm audio/x-mod

xml text/xml

xmz audio/x-mod

xpi application/x-xpinstall

xpm image/x-xpixmap

xsit text/xml

xsl text/xml

xul text/xul

xwd image/x-xwindowdump

xyz chemical/x-pdb

yz1 application/x-yz1

z application/x-compress

zac application/x-zaurus-zac

zip application/zip

内容传输编码(Content-Transfer-Encoding),这个区域使指定ASCII以外的字符编码方式成为可能。形式如下:

Content-Transfer-Encoding: [mechanism]

其中,mechanism的值可以指定为“7bit”,“8bit”,“binary”,“quoted-printable”,“base64”。

7bit

7bit这里指的是7位的ASCII编码方式。

8bit

8位元ASCII码。

binary

quoted-printable

因为欧洲的一些文字和ASCII字符集中的某些字符有部分相同。如果邮件消息使用的是这些语言的话,于ASCII重叠的那些字符可以原样使用,ASCII字符集中不存在的字符采用形如“=??”的方法编码。这里“??”需要用将字符编码后的16进制数字来指定。采用quoted-printable编码的消息,长度不会变得太长,而且大部分都是ASCII中的字符,即使不通过解码也大致可以读懂消息的内容。

base64

base64是一种将二进制的01序列转化成ASCII字符的编码方法。编码后的文本或者二进制消息,就可以运用SMTP等只支持ASCII字符的协议传送了。Base64一般被认为会平均增加33%的报文长度,而且,经过编码的消息对于人类来说是不可读的。

x-encodingname

这个值是预留的扩展。

All rights reserved Powered by 网络热词 87994.com

copyright ©right 2010-2020。
网络热词内容来自网络,如有侵犯请联系客服。zhit325@126.com