提问：同一个后缀名对应多个MIME值是什么情况，怎么解释。希望有明白的能留言交流。
我只是将W3C中的两个表格整理成了二维数组的格式：
/**
* 按照内容类型排列的 Mime 类型列表
*/
String[][] MimeTableFirst = {
{"application/envoy","evy"},
{"application/fractals","fif"},
{"application/futuresplash","spl"},
{"application/hta","hta"},
{"application/internet-property-stream","a"},
{"application/mac-binhex40","hqx"},
{"application/msword","doc"},
{"application/msword","dot"},
{"application/octet-stream","*"},
{"application/octet-stream","bin"},
{"application/octet-stream","class"},
{"application/octet-stream","dms"},
{"application/octet-stream","exe"},
{"application/octet-stream","lha"},
{"application/octet-stream","lzh"},
{"application/oda","oda"},
{"application/olescript","axs"},
{"application/pdf","pdf"},
{"application/pics-rules","prf"},
{"application/pkcs10","p10"},
{"application/pkix-crl","crl"},
{"application/postscript","ai"},
{"application/postscript","eps"},
{"application/postscript","ps"},
{"application/rtf","rtf"},
{"application/set-payment-initiation","set"},
{"application/set-registration-initiation",""},
{"application/vnd.ms-excel","xla"},
{"application/vnd.ms-excel","xlc"},
{"application/vnd.ms-excel","xlm"},
{"application/vnd.ms-excel","xls"},
{"application/vnd.ms-excel","xlt"},
{"application/vnd.ms-excel","xlw"},
{"application/vnd.ms-outlook","msg"},
{"application/vnd.ms-pkicertstore","sst"},
{"application/vnd.ms-pkiseccat","cat"},
{"application/vnd.ms-pkistl","stl"},
{"application/vnd.ms-powerpoint","pot"},
{"application/vnd.ms-powerpoint","pps"},
{"application/vnd.ms-powerpoint","ppt"},
{"application/vnd.ms-project","mpp"},
{"application/vnd.ms-works","wcm"},
{"application/vnd.ms-works","wdb"},
{"application/vnd.ms-works","wks"},
{"application/vnd.ms-works","wps"},
{"application/winhlp","hlp"},
{"application/x-bcpio","bcpio"},
{"application/x-cdf","cdf"},
{"application/x-compress","z"},
{"application/x-compressed","tgz"},
{"application/x-cpio","cpio"},
{"application/x-csh","csh"},
{"application/x-director","dcr"},
{"application/x-director","dir"},
{"application/x-director","dxr"},
{"application/x-dvi","dvi"},
{"application/x-gtar","gtar"},
{"application/x-gzip","gz"},
{"application/x-hdf","hdf"},
{"application/x-internet-signup","ins"},
{"application/x-internet-signup","isp"},
{"application/x-iphone","iii"},
{"application/x-javascript","js"},
{"application/x-latex","latex"},
{"application/x-msaccess","mdb"},
{"application/x-mscardfile","crd"},
{"application/x-msclip","clp"},
{"application/x-msdownload","dll"},
{"application/x-msmediaview","m13"},
{"application/x-msmediaview","m14"},
{"application/x-msmediaview","mvb"},
{"application/x-msmetafile","wmf"},
{"application/x-msmoney","mny"},
{"application/x-mspublisher","pub"},
{"application/x-msschedule","scd"},
{"application/x-msterminal","trm"},
{"application/x-mswrite","wri"},
{"application/x-netcdf","cdf"},
{"application/x-netcdf","nc"},
{"application/x-perfmon","pma"},
{"application/x-perfmon","pmc"},
{"application/x-perfmon","pml"},
{"application/x-perfmon","pmr"},
{"application/x-perfmon","pmw"},
{"application/x-pkcs12","p12"},
{"application/x-pkcs12","pfx"},
{"application/x-pkcs7-certificates","p7b"},
{"application/x-pkcs7-certificates","spc"},
{"application/x-pkcs7-certreqresp","p7r"},
{"application/x-pkcs7-mime","p7c"},
{"application/x-pkcs7-mime","p7m"},
{"application/x-pkcs7-signature","p7s"},
{"application/x-sh","sh"},
{"application/x-shar","shar"},
{"application/x-shockwave-flash","swf"},
{"application/x-stuffit","sit"},
{"application/x-sv4cpio","sv4cpio"},
{"application/x-sv4crc","sv4crc"},
{"application/x-tar","tar"},
{"application/x-tcl","tcl"},
{"application/x-tex","tex"},
{"application/x-texinfo","texi"},
{"application/x-texinfo","texinfo"},
{"application/x-troff","roff"},
{"application/x-troff","t"},
{"application/x-troff","tr"},
{"application/x-troff-man","man"},
{"application/x-troff-me","me"},
{"application/x-troff-ms","ms"},
{"application/x-ustar","ustar"},
{"application/x-wais-source","src"},
{"application/x-x509-ca-cert","cer"},
{"application/x-x509-ca-cert","crt"},
{"application/x-x509-ca-cert","der"},
{"application/ynd.ms-pkipko","pko"},
{"application/zip","zip"},
{"audio/basic","au"},
{"audio/basic","snd"},
{"audio/mid","mid"},
{"audio/mid","rmi"},
{"audio/mpeg","mp3"},
{"audio/x-aiff","aif"},
{"audio/x-aiff","aifc"},
{"audio/x-aiff","aiff"},
{"audio/x-mpegurl","m3u"},
{"audio/x-pn-realaudio","ra"},
{"audio/x-pn-realaudio","ram"},
{"audio/x-wav","wav"},
{"image/bmp","bmp"},
{"image/cis-cod","cod"},
{"image/gif","gif"},
{"image/ief","ief"},
{"image/jpeg","jpe"},
{"image/jpeg","jpeg"},
{"image/jpeg","jpg"},
{"image/pipeg","jfif"},
{"image/svg+xml","svg"},
{"image/tiff","tif"},
{"image/tiff","tiff"},
{"image/x-cmu-raster","ras"},
{"image/x-cmx","cmx"},
{"image/x-icon","ico"},
{"image/x-portable-anymap","pnm"},
{"image/x-portable-bitmap","pbm"},
{"image/x-portable-graymap","pgm"},
{"image/x-portable-pixmap","ppm"},
{"image/x-rgb","rgb"},
{"image/x-xbitmap","xbm"},
{"image/x-xpixmap","xpm"},
{"image/x-xwindowdump","xwd"},
{"message/rfc822","mht"},
{"message/rfc822","mhtml"},
{"message/rfc822","nws"},
{"text/css","css"},
{"text/h323","323"},
{"text/html","htm"},
{"text/html","html"},
{"text/html","stm"},
{"text/iuls","uls"},
{"text/plain","bas"},
{"text/plain","c"},
{"text/plain","h"},
{"text/plain","txt"},
{"text/richtext","rtx"},
{"text/scriptlet","sct"},
{"text/tab-separated-values","tsv"},
{"text/webviewhtml","htt"},
{"text/x-component","htc"},
{"text/x-setext","etx"},
{"text/x-vcard","vcf"},
{"video/mpeg","mp2"},
{"video/mpeg","mpa"},
{"video/mpeg","mpe"},
{"video/mpeg","mpeg"},
{"video/mpeg","mpg"},
{"video/mpeg","mpv2"},
{"video/quicktime","mov"},
{"video/quicktime","qt"},
{"video/x-la-asf","lsf"},
{"video/x-la-asf","lsx"},
{"video/x-ms-asf","asf"},
{"video/x-ms-asf","asr"},
{"video/x-ms-asf","asx"},
{"video/x-msvideo","avi"},
{"video/x-sgi-movie","movie"},
{"x-world/x-vrml","flr"},
{"x-world/x-vrml","vrml"},
{"x-world/x-vrml","wrl"},
{"x-world/x-vrml","wrz"},
{"x-world/x-vrml","xaf"},
{"x-world/x-vrml","xof"}
};
/**
* 按照文件扩展名排列的 Mime 类型列表
*/
String[][] MimeTableSecond = {
{"*","application/octet-stream"},
{"323","text/h323"},
{"acx","application/internet-property-stream"},
{"ai","application/postscript"},
{"aif","audio/x-aiff"},
{"aifc","audio/x-aiff"},
{"aiff","audio/x-aiff"},
{"asf","video/x-ms-asf"},
{"asr","video/x-ms-asf"},
{"asx","video/x-ms-asf"},
{"au","audio/basic"},
{"avi","video/x-msvideo"},
{"axs","application/olescript"},
{"bas","text/plain"},
{"bcpio","application/x-bcpio"},
{"bin","application/octet-stream"},
{"bmp","image/bmp"},
{"c","text/plain"},
{"cat","application/vnd.ms-pkiseccat"},
{"cdf","application/x-cdf"},
{"cer","application/x-x509-ca-cert"},
{"class","application/octet-stream"},
{"clp","application/x-msclip"},
{"cmx","image/x-cmx"},
{"cod","image/cis-cod"},
{"cpio","application/x-cpio"},
{"crd","application/x-mscardfile"},
{"crl","application/pkix-crl"},
{"crt","application/x-x509-ca-cert"},
{"csh","application/x-csh"},
{"css","text/css"},
{"dcr","application/x-director"},
{"der","application/x-x509-ca-cert"},
{"dir","application/x-director"},
{"dll","application/x-msdownload"},
{"dms","application/octet-stream"},
{"doc","application/msword"},
{"dot","application/msword"},
{"dvi","application/x-dvi"},
{"dxr","application/x-director"},
{"eps","application/postscript"},
{"etx","text/x-setext"},
{"evy","application/envoy"},
{"exe","application/octet-stream"},
{"fif","application/fractals"},
{"flr","x-world/x-vrml"},
{"gif","image/gif"},
{"gtar","application/x-gtar"},
{"gz","application/x-gzip"},
{"h","text/plain"},
{"hdf","application/x-hdf"},
{"hlp","application/winhlp"},
{"hqx","application/mac-binhex40"},
{"hta","application/hta"},
{"htc","text/x-component"},
{"htm","text/html"},
{"html","text/html"},
{"htt","text/webviewhtml"},
{"ico","image/x-icon"},
{"ief","image/ief"},
{"iii","application/x-iphone"},
{"ins","application/x-internet-signup"},
{"isp","application/x-internet-signup"},
{"jfif","image/pipeg"},
{"jpe","image/jpeg"},
{"jpeg","image/jpeg"},
{"jpg","image/jpeg"},
{"js","application/x-javascript"},
{"latex","application/x-latex"},
{"lha","application/octet-stream"},
{"lsf","video/x-la-asf"},
{"lsx","video/x-la-asf"},
{"lzh","application/octet-stream"},
{"m13","application/x-msmediaview"},
{"m14","application/x-msmediaview"},
{"m3u","audio/x-mpegurl"},
{"man","application/x-troff-man"},
{"mdb","application/x-msaccess"},
{"me","application/x-troff-me"},
{"mht","message/rfc822"},
{"mhtml","message/rfc822"},
{"mid","audio/mid"},
{"mny","application/x-msmoney"},
{"mov","video/quicktime"},
{"movie","video/x-sgi-movie"},
{"mp2","video/mpeg"},
{"mp3","audio/mpeg"},
{"mpa","video/mpeg"},
{"mpe","video/mpeg"},
{"mpeg","video/mpeg"},
{"mpg","video/mpeg"},
{"mpp","application/vnd.ms-project"},
{"mpv2","video/mpeg"},
{"ms","application/x-troff-ms"},
{"mvb","application/x-msmediaview"},
{"nws","message/rfc822"},
{"oda","application/oda"},
{"p10","application/pkcs10"},
{"p12","application/x-pkcs12"},
{"p7b","application/x-pkcs7-certificates"},
{"p7c","application/x-pkcs7-mime"},
{"p7m","application/x-pkcs7-mime"},
{"p7r","application/x-pkcs7-certreqresp"},
{"p7s","application/x-pkcs7-signature"},
{"pbm","image/x-portable-bitmap"},
{"pdf","application/pdf"},
{"pfx","application/x-pkcs12"},
{"pgm","image/x-portable-graymap"},
{"pko","application/ynd.ms-pkipko"},
{"pma","application/x-perfmon"},
{"pmc","application/x-perfmon"},
{"pml","application/x-perfmon"},
{"pmr","application/x-perfmon"},
{"pmw","application/x-perfmon"},
{"pnm","image/x-portable-anymap"},
{"pot,","application/vnd.ms-powerpoint"},
{"ppm","image/x-portable-pixmap"},
{"pps","application/vnd.ms-powerpoint"},
{"ppt","application/vnd.ms-powerpoint"},
{"prf","application/pics-rules"},
{"ps","application/postscript"},
{"pub","application/x-mspublisher"},
{"qt","video/quicktime"},
{"ra","audio/x-pn-realaudio"},
{"ram","audio/x-pn-realaudio"},
{"ras","image/x-cmu-raster"},
{"rgb","image/x-rgb"},
{"rmi","audio/mid"},
{"roff","application/x-troff"},
{"rtf","application/rtf"},
{"rtx","text/richtext"},
{"scd","application/x-msschedule"},
{"sct","text/scriptlet"},
{"setpay","application/set-payment-initiation"},
{"setreg","application/set-registration-initiation"},
{"sh","application/x-sh"},
{"shar","application/x-shar"},
{"sit","application/x-stuffit"},
{"snd","audio/basic"},
{"spc","application/x-pkcs7-certificates"},
{"spl","application/futuresplash"},
{"src","application/x-wais-source"},
{"sst","application/vnd.ms-pkicertstore"},
{"stl","application/vnd.ms-pkistl"},
{"stm","text/html"},
{"svg","image/svg+xml"},
{"sv4cpio","application/x-sv4cpio"},
{"sv4crc","application/x-sv4crc"},
{"swf","application/x-shockwave-flash"},
{"t","application/x-troff"},
{"tar","application/x-tar"},
{"tcl","application/x-tcl"},
{"tex","application/x-tex"},
{"texi","application/x-texinfo"},
{"texinfo","application/x-texinfo"},
{"tgz","application/x-compressed"},
{"tif","image/tiff"},
{"tiff","image/tiff"},
{"tr","application/x-troff"},
{"trm","application/x-msterminal"},
{"tsv","text/tab-separated-values"},
{"txt","text/plain"},
{"uls","text/iuls"},
{"ustar","application/x-ustar"},
{"vcf","text/x-vcard"},
{"vrml","x-world/x-vrml"},
{"wav","audio/x-wav"},
{"wcm","application/vnd.ms-works"},
{"wdb","application/vnd.ms-works"},
{"wks","application/vnd.ms-works"},
{"wmf","application/x-msmetafile"},
{"wps","application/vnd.ms-works"},
{"wri","application/x-mswrite"},
{"wrl","x-world/x-vrml"},
{"wrz","x-world/x-vrml"},
{"xaf","x-world/x-vrml"},
{"xbm","image/x-xbitmap"},
{"xla","application/vnd.ms-excel"},
{"xlc","application/vnd.ms-excel"},
{"xlm","application/vnd.ms-excel"},
{"xls","application/vnd.ms-excel"},
{"xlt","application/vnd.ms-excel"},
{"xlw","application/vnd.ms-excel"},
{"xof","x-world/x-vrml"},
{"xpm","image/x-xpixmap"},
{"xwd","image/x-xwindowdump"},
{"z","application/x-compress"},
{"zip","application/zip"}
};
来自小米文件管理器：
package net.micode.fileexplorer;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
/**
* Utilities for dealing with MIME types.
* Used to implement java.net.URLConnection and android.webkit.MimeTypeMap.
*/
public final class MimeUtils {
private static final Map mimeTypeToExtensionMap = new HashMap();
private static final Map extensionToMimeTypeMap = new HashMap();
static {
add("application/andrew-inset", "ez");
add("application/dsptype", "tsp");
add("application/futuresplash", "spl");
add("application/hta", "hta");
add("application/mac-binhex40", "hqx");
add("application/mac-compactpro", "cpt");
add("application/mathematica", "nb");
add("application/msaccess", "mdb");
add("application/oda", "oda");
add("application/ogg", "ogg");
add("application/pdf", "pdf");
add("application/pgp-keys", "key");
add("application/pgp-signature", "pgp");
add("application/pics-rules", "prf");
add("application/rar", "rar");
add("application/rdf+xml", "rdf");
add("application/rss+xml", "rss");
add("application/zip", "zip");
add("application/vnd.android.package-archive", "apk");
add("application/vnd.cinderella", "cdy");
add("application/vnd.ms-pki.stl", "stl");
add("application/vnd.oasis.opendocument.database", "odb");
add("application/vnd.oasis.opendocument.formula", "odf");
add("application/vnd.oasis.opendocument.graphics", "odg");
add("application/vnd.oasis.opendocument.graphics-template", "otg");
add("application/vnd.oasis.opendocument.image", "odi");
add("application/vnd.oasis.opendocument.spreadsheet", "ods");
add("application/vnd.oasis.opendocument.spreadsheet-template", "ots");
add("application/vnd.oasis.opendocument.text", "odt");
add("application/vnd.oasis.opendocument.text-master", "odm");
add("application/vnd.oasis.opendocument.text-template", "ott");
add("application/vnd.oasis.opendocument.text-web", "oth");
add("application/vnd.google-earth.kml+xml", "kml");
add("application/vnd.google-earth.kmz", "kmz");
add("application/msword", "doc");
add("application/msword", "dot");
add("application/vnd.openxmlformats-officedocument.wordprocessingml.document", "docx");
add("application/vnd.openxmlformats-officedocument.wordprocessingml.template", "dotx");
add("application/vnd.ms-excel", "xls");
add("application/vnd.ms-excel", "xlt");
add("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "xlsx");
add("application/vnd.openxmlformats-officedocument.spreadsheetml.template", "xltx");
add("application/vnd.ms-powerpoint", "ppt");
add("application/vnd.ms-powerpoint", "pot");
add("application/vnd.ms-powerpoint", "pps");
add("application/vnd.openxmlformats-officedocument.presentationml.presentation", "pptx");
add("application/vnd.openxmlformats-officedocument.presentationml.template", "potx");
add("application/vnd.openxmlformats-officedocument.presentationml.slideshow", "ppsx");
add("application/vnd.rim.cod", "cod");
add("application/vnd.smaf", "mmf");
add("application/vnd.stardivision.calc", "sdc");
add("application/vnd.stardivision.draw", "sda");
add("application/vnd.stardivision.impress", "sdd");
add("application/vnd.stardivision.impress", "sdp");
add("application/vnd.stardivision.math", "smf");
add("application/vnd.stardivision.writer", "sdw");
add("application/vnd.stardivision.writer", "vor");
add("application/vnd.stardivision.writer-global", "sgl");
add("application/vnd.sun.xml.calc", "sxc");
add("application/vnd.sun.xml.calc.template", "stc");
add("application/vnd.sun.xml.draw", "sxd");
add("application/vnd.sun.xml.draw.template", "std");
add("application/vnd.sun.xml.impress", "sxi");
add("application/vnd.sun.xml.impress.template", "sti");
add("application/vnd.sun.xml.math", "sxm");
add("application/vnd.sun.xml.writer", "sxw");
add("application/vnd.sun.xml.writer.global", "sxg");
add("application/vnd.sun.xml.writer.template", "stw");
add("application/vnd.visio", "vsd");
add("application/x-abiword", "abw");
add("application/x-apple-diskimage", "dmg");
add("application/x-bcpio", "bcpio");
add("application/x-bittorrent", "torrent");
add("application/x-cdf", "cdf");
add("application/x-cdlink", "vcd");
add("application/x-chess-pgn", "pgn");
add("application/x-cpio", "cpio");
add("application/x-debian-package", "deb");
add("application/x-debian-package", "udeb");
add("application/x-director", "dcr");
add("application/x-director", "dir");
add("application/x-director", "dxr");
add("application/x-dms", "dms");
add("application/x-doom", "wad");
add("application/x-dvi", "dvi");
add("application/x-flac", "flac");
add("application/x-font", "pfa");
add("application/x-font", "pfb");
add("application/x-font", "gsf");
add("application/x-font", "pcf");
add("application/x-font", "pcf.Z");
add("application/x-freemind", "mm");
add("application/x-futuresplash", "spl");
add("application/x-gnumeric", "gnumeric");
add("application/x-go-sgf", "sgf");
add("application/x-graphing-calculator", "gcf");
add("application/x-gtar", "gtar");
add("application/x-gtar", "tgz");
add("application/x-gtar", "taz");
add("application/x-hdf", "hdf");
add("application/x-ica", "ica");
add("application/x-internet-signup", "ins");
add("application/x-internet-signup", "isp");
add("application/x-iphone", "iii");
add("application/x-iso9660-image", "iso");
add("application/x-jmol", "jmz");
add("application/x-kchart", "chrt");
add("application/x-killustrator", "kil");
add("application/x-koan", "skp");
add("application/x-koan", "skd");
add("application/x-koan", "skt");
add("application/x-koan", "skm");
add("application/x-kpresenter", "kpr");
add("application/x-kpresenter", "kpt");
add("application/x-kspread", "ksp");
add("application/x-kword", "kwd");
add("application/x-kword", "kwt");
add("application/x-latex", "latex");
add("application/x-lha", "lha");
add("application/x-lzh", "lzh");
add("application/x-lzx", "lzx");
add("application/x-maker", "frm");
add("application/x-maker", "maker");
add("application/x-maker", "frame");
add("application/x-maker", "fb");
add("application/x-maker", "book");
add("application/x-maker", "fbdoc");
add("application/x-mif", "mif");
add("application/x-ms-wmd", "wmd");
add("application/x-ms-wmz", "wmz");
add("application/x-msi", "msi");
add("application/x-ns-proxy-autoconfig", "pac");
add("application/x-nwc", "nwc");
add("application/x-object", "o");
add("application/x-oz-application", "oza");
add("application/x-pkcs12", "p12");
add("application/x-pkcs7-certreqresp", "p7r");
add("application/x-pkcs7-crl", "crl");
add("application/x-quicktimeplayer", "qtl");
add("application/x-shar", "shar");
add("application/x-shockwave-flash", "swf");
add("application/x-stuffit", "sit");
add("application/x-sv4cpio", "sv4cpio");
add("application/x-sv4crc", "sv4crc");
add("application/x-tar", "tar");
add("application/x-texinfo", "texinfo");
add("application/x-texinfo", "texi");
add("application/x-troff", "t");
add("application/x-troff", "roff");
add("application/x-troff-man", "man");
add("application/x-ustar", "ustar");
add("application/x-wais-source", "src");
add("application/x-wingz", "wz");
add("application/x-webarchive", "webarchive");
add("application/x-webarchive-xml", "webarchivexml");
add("application/x-x509-ca-cert", "crt");
add("application/x-x509-user-cert", "crt");
add("application/x-xcf", "xcf");
add("application/x-xfig", "fig");
add("application/xhtml+xml", "xhtml");
add("audio/3gpp", "3gpp");
add("audio/amr", "amr");
add("audio/basic", "snd");
add("audio/midi", "mid");
add("audio/midi", "midi");
add("audio/midi", "kar");
add("audio/midi", "xmf");
add("audio/mobile-xmf", "mxmf");
add("audio/mpeg", "mpga");
add("audio/mpeg", "mpega");
add("audio/mpeg", "mp2");
add("audio/mpeg", "mp3");
add("audio/mpeg", "m4a");
add("audio/mpegurl", "m3u");
add("audio/prs.sid", "sid");
add("audio/x-aiff", "aif");
add("audio/x-aiff", "aiff");
add("audio/x-aiff", "aifc");
add("audio/x-gsm", "gsm");
add("audio/x-mpegurl", "m3u");
add("audio/x-ms-wma", "wma");
add("audio/x-ms-wax", "wax");
add("audio/x-pn-realaudio", "ra");
add("audio/x-pn-realaudio", "rm");
add("audio/x-pn-realaudio", "ram");
add("audio/x-realaudio", "ra");
add("audio/x-scpls", "pls");
add("audio/x-sd2", "sd2");
add("audio/x-wav", "wav");
add("image/bmp", "bmp");
add("audio/x-qcp", "qcp");
add("image/gif", "gif");
add("image/ico", "cur");
add("image/ico", "ico");
add("image/ief", "ief");
add("image/jpeg", "jpeg");
add("image/jpeg", "jpg");
add("image/jpeg", "jpe");
add("image/pcx", "pcx");
add("image/png", "png");
add("image/svg+xml", "svg");
add("image/svg+xml", "svgz");
add("image/tiff", "tiff");
add("image/tiff", "tif");
add("image/vnd.djvu", "djvu");
add("image/vnd.djvu", "djv");
add("image/vnd.wap.wbmp", "wbmp");
add("image/x-cmu-raster", "ras");
add("image/x-coreldraw", "cdr");
add("image/x-coreldrawpattern", "pat");
add("image/x-coreldrawtemplate", "cdt");
add("image/x-corelphotopaint", "cpt");
add("image/x-icon", "ico");
add("image/x-jg", "art");
add("image/x-jng", "jng");
add("image/x-ms-bmp", "bmp");
add("image/x-photoshop", "psd");
add("image/x-portable-anymap", "pnm");
add("image/x-portable-bitmap", "pbm");
add("image/x-portable-graymap", "pgm");
add("image/x-portable-pixmap", "ppm");
add("image/x-rgb", "rgb");
add("image/x-xbitmap", "xbm");
add("image/x-xpixmap", "xpm");
add("image/x-xwindowdump", "xwd");
add("model/iges", "igs");
add("model/iges", "iges");
add("model/mesh", "msh");
add("model/mesh", "mesh");
add("model/mesh", "silo");
add("text/calendar", "ics");
add("text/calendar", "icz");
add("text/comma-separated-values", "csv");
add("text/css", "css");
add("text/html", "htm");
add("text/html", "html");
add("text/h323", "323");
add("text/iuls", "uls");
add("text/mathml", "mml");
add("text/plain", "txt");
add("text/plain", "asc");
add("text/plain", "text");
add("text/plain", "diff");
add("text/plain", "po");
add("text/richtext", "rtx");
add("text/rtf", "rtf");
add("text/texmacs", "ts");
add("text/text", "phps");
add("text/tab-separated-values", "tsv");
add("text/xml", "xml");
add("text/x-bibtex", "bib");
add("text/x-boo", "boo");
add("text/x-c++hdr", "h++");
add("text/x-c++hdr", "hpp");
add("text/x-c++hdr", "hxx");
add("text/x-c++hdr", "hh");
add("text/x-c++src", "c++");
add("text/x-c++src", "cpp");
add("text/x-c++src", "cxx");
add("text/x-chdr", "h");
add("text/x-component", "htc");
add("text/x-csh", "csh");
add("text/x-csrc", "c");
add("text/x-dsrc", "d");
add("text/x-haskell", "hs");
add("text/x-java", "java");
add("text/x-literate-haskell", "lhs");
add("text/x-moc", "moc");
add("text/x-pascal", "p");
add("text/x-pascal", "pas");
add("text/x-pcs-gcd", "gcd");
add("text/x-setext", "etx");
add("text/x-tcl", "tcl");
add("text/x-tex", "tex");
add("text/x-tex", "ltx");
add("text/x-tex", "sty");
add("text/x-tex", "cls");
add("text/x-vcalendar", "vcs");
add("text/x-vcard", "vcf");
add("video/3gpp", "3gpp");
add("video/3gpp", "3gp");
add("video/3gpp", "3g2");
add("video/dl", "dl");
add("video/dv", "dif");
add("video/dv", "dv");
add("video/fli", "fli");
add("video/m4v", "m4v");
add("video/mpeg", "mpeg");
add("video/mpeg", "mpg");
add("video/mpeg", "mpe");
add("video/mp4", "mp4");
add("video/mpeg", "VOB");
add("video/quicktime", "qt");
add("video/quicktime", "mov");
add("video/vnd.mpegurl", "mxu");
add("video/webm", "webm");
add("video/x-la-asf", "lsf");
add("video/x-la-asf", "lsx");
add("video/x-mng", "mng");
add("video/x-ms-asf", "asf");
add("video/x-ms-asf", "asx");
add("video/x-ms-wm", "wm");
add("video/x-ms-wmv", "wmv");
add("video/x-ms-wmx", "wmx");
add("video/x-ms-wvx", "wvx");
add("video/x-msvideo", "avi");
add("video/x-sgi-movie", "movie");
add("x-conference/x-cooltalk", "ice");
add("x-epoc/x-sisx-app", "sisx");
applyOverrides();
}
private static void add(String mimeType, String extension) {
if (!mimeTypeToExtensionMap.containsKey(mimeType)) {
mimeTypeToExtensionMap.put(mimeType, extension);
}
extensionToMimeTypeMap.put(extension, mimeType);
}
private static InputStream getContentTypesPropertiesStream() {
String userTable = System.getProperty("content.types.user.table");
if (userTable != null) {
File f = new File(userTable);
if (f.exists()) {
try {
return new FileInputStream(f);
} catch (IOException ignored) {
}
}
}
File f = new File(System.getProperty("java.home"), "lib" + File.separator + "content-types.properties");
if (f.exists()) {
try {
return new FileInputStream(f);
} catch (IOException ignored) {
}
}
return null;
}
/**
* This isn't what the RI does. The RI doesn't have hard-coded defaults, so supplying your
* own "content.types.user.table" means you don't get any of the built-ins, and the built-ins
* come from "$JAVA_HOME/lib/content-types.properties".
*/
private static void applyOverrides() {
InputStream stream = getContentTypesPropertiesStream();
if (stream == null) {
return;
}
try {
try {
Properties overrides = new Properties();
overrides.load(stream);
for (Map.Entry entry : overrides.entrySet()) {
String extension = (String) entry.getKey();
String mimeType = (String) entry.getValue();
add(mimeType, extension);
}
} finally {
stream.close();
}
} catch (IOException ignored) {
}
}
private MimeUtils() {
}
/**
* Returns true if the given MIME type has an entry in the map.
* @param mimeType A MIME type (i.e. text/plain)
* @return True iff there is a mimeType entry in the map.
*/
public static boolean hasMimeType(String mimeType) {
if (mimeType == null || mimeType.isEmpty()) {
return false;
}
return mimeTypeToExtensionMap.containsKey(mimeType);
}
/**
* Returns the MIME type for the given extension.
* @param extension A file extension without the leading '.'
* @return The MIME type for the given extension or null iff there is none.
*/
public static String guessMimeTypeFromExtension(String extension) {
if (extension == null || extension.isEmpty()) {
return null;
}
return extensionToMimeTypeMap.get(extension);
}
/**
* Returns true if the given extension has a registered MIME type.
* @param extension A file extension without the leading '.'
* @return True iff there is an extension entry in the map.
*/
public static boolean hasExtension(String extension) {
if (extension == null || extension.isEmpty()) {
return false;
}
return extensionToMimeTypeMap.containsKey(extension);
}
/**
* Returns the registered extension for the given MIME type. Note that some
* MIME types map to multiple extensions. This call will return the most
* common extension for the given MIME type.
* @param mimeType A MIME type (i.e. text/plain)
* @return The extension for the given MIME type or null iff there is none.
*/
public static String guessExtensionFromMimeType(String mimeType) {
if (mimeType == null || mimeType.isEmpty()) {
return null;
}
return mimeTypeToExtensionMap.get(mimeType);
}
}
键值对颠倒整理
("ez","application/andrew-inset")
("tsp","application/dsptype")
("spl","application/futuresplash")
("hta","application/hta")
("hqx","application/mac-binhex40")
("cpt","application/mac-compactpro")
("nb","application/mathematica")
("mdb","application/msaccess")
("oda","application/oda")
("ogg","application/ogg")
("pdf","application/pdf")
("key","application/pgp-keys")
("pgp","application/pgp-signature")
("prf","application/pics-rules")
("rar","application/rar")
("rdf","application/rdf+xml")
("rss","application/rss+xml")
("zip","application/zip")
("apk","application/vnd.android.package-archive")
("cdy","application/vnd.cinderella")
("stl","application/vnd.ms-pki.stl")
("odb","application/vnd.oasis.opendocument.database")
("odf","application/vnd.oasis.opendocument.formula")
("odg","application/vnd.oasis.opendocument.graphics")
("otg","application/vnd.oasis.opendocument.graphics-template")
("odi","application/vnd.oasis.opendocument.image")
("ods","application/vnd.oasis.opendocument.spreadsheet")
("ots","application/vnd.oasis.opendocument.spreadsheet-template")
("odt","application/vnd.oasis.opendocument.text")
("odm","application/vnd.oasis.opendocument.text-master")
("ott","application/vnd.oasis.opendocument.text-template")
("oth","application/vnd.oasis.opendocument.text-web")
("kml","application/vnd.google-earth.kml+xml")
("kmz","application/vnd.google-earth.kmz")
("doc","application/msword")
("dot","application/msword")
("docx","application/vnd.openxmlformats-officedocument.wordprocessingml.document")
("dotx","application/vnd.openxmlformats-officedocument.wordprocessingml.template")
("xls","application/vnd.ms-excel")
("xlt","application/vnd.ms-excel")
("xlsx","application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
("xltx","application/vnd.openxmlformats-officedocument.spreadsheetml.template")
("ppt","application/vnd.ms-powerpoint")
("pot","application/vnd.ms-powerpoint")
("pps","application/vnd.ms-powerpoint")
("pptx","application/vnd.openxmlformats-officedocument.presentationml.presentation")
("potx","application/vnd.openxmlformats-officedocument.presentationml.template")
("ppsx","application/vnd.openxmlformats-officedocument.presentationml.slideshow")
("cod","application/vnd.rim.cod")
("mmf","application/vnd.smaf")
("sdc","application/vnd.stardivision.calc")
("sda","application/vnd.stardivision.draw")
("sdd","application/vnd.stardivision.impress")
("sdp","application/vnd.stardivision.impress")
("smf","application/vnd.stardivision.math")
("sdw","application/vnd.stardivision.writer")
("vor","application/vnd.stardivision.writer")
("sgl","application/vnd.stardivision.writer-global")
("sxc","application/vnd.sun.xml.calc")
("stc","application/vnd.sun.xml.calc.template")
("sxd","application/vnd.sun.xml.draw")
("std","application/vnd.sun.xml.draw.template")
("sxi","application/vnd.sun.xml.impress")
("sti","application/vnd.sun.xml.impress.template")
("sxm","application/vnd.sun.xml.math")
("sxw","application/vnd.sun.xml.writer")
("sxg","application/vnd.sun.xml.writer.global")
("stw","application/vnd.sun.xml.writer.template")
("vsd","application/vnd.visio")
("abw","application/x-abiword")
("dmg","application/x-apple-diskimage")
("bcpio","application/x-bcpio")
("torrent","application/x-bittorrent")
("cdf","application/x-cdf")
("vcd","application/x-cdlink")
("pgn","application/x-chess-pgn")
("cpio","application/x-cpio")
("deb","application/x-debian-package")
("udeb","application/x-debian-package")
("dcr","application/x-director")
("dir","application/x-director")
("dxr","application/x-director")
("dms","application/x-dms")
("wad","application/x-doom")
("dvi","application/x-dvi")
("flac","application/x-flac")
("pfa","application/x-font")
("pfb","application/x-font")
("gsf","application/x-font")
("pcf","application/x-font")
("pcf.z","application/x-font")
("mm","application/x-freemind")
("spl","application/x-futuresplash")
("gnumeric","application/x-gnumeric")
("sgf","application/x-go-sgf")
("gcf","application/x-graphing-calculator")
("gtar","application/x-gtar")
("tgz","application/x-gtar")
("taz","application/x-gtar")
("hdf","application/x-hdf")
("ica","application/x-ica")
("ins","application/x-internet-signup")
("isp","application/x-internet-signup")
("iii","application/x-iphone")
("iso","application/x-iso9660-image")
("jmz","application/x-jmol")
("chrt","application/x-kchart")
("kil","application/x-killustrator")
("skp","application/x-koan")
("skd","application/x-koan")
("skt","application/x-koan")
("skm","application/x-koan")
("kpr","application/x-kpresenter")
("kpt","application/x-kpresenter")
("ksp","application/x-kspread")
("kwd","application/x-kword")
("kwt","application/x-kword")
("latex","application/x-latex")
("lha","application/x-lha")
("lzh","application/x-lzh")
("lzx","application/x-lzx")
("frm","application/x-maker")
("maker","application/x-maker")
("frame","application/x-maker")
("fb","application/x-maker")
("book","application/x-maker")
("fbdoc","application/x-maker")
("mif","application/x-mif")
("wmd","application/x-ms-wmd")
("wmz","application/x-ms-wmz")
("msi","application/x-msi")
("pac","application/x-ns-proxy-autoconfig")
("nwc","application/x-nwc")
("o","application/x-object")
("oza","application/x-oz-application")
("p12","application/x-pkcs12")
("p7r","application/x-pkcs7-certreqresp")
("crl","application/x-pkcs7-crl")
("qtl","application/x-quicktimeplayer")
("shar","application/x-shar")
("swf","application/x-shockwave-flash")
("sit","application/x-stuffit")
("sv4cpio","application/x-sv4cpio")
("sv4crc","application/x-sv4crc")
("tar","application/x-tar")
("texinfo","application/x-texinfo")
("texi","application/x-texinfo")
("t","application/x-troff")
("roff","application/x-troff")
("man","application/x-troff-man")
("ustar","application/x-ustar")
("src","application/x-wais-source")
("wz","application/x-wingz")
("webarchive","application/x-webarchive")
("webarchivexml","application/x-webarchive-xml")
("crt","application/x-x509-ca-cert")
("crt","application/x-x509-user-cert")
("xcf","application/x-xcf")
("fig","application/x-xfig")
("xhtml","application/xhtml+xml")
("3gpp","audio/3gpp")
("amr","audio/amr")
("snd","audio/basic")
("mid","audio/midi")
("midi","audio/midi")
("kar","audio/midi")
("xmf","audio/midi")
("mxmf","audio/mobile-xmf")
("mpga","audio/mpeg")
("mpega","audio/mpeg")
("mp2","audio/mpeg")
("mp3","audio/mpeg")
("m4a","audio/mpeg")
("m3u","audio/mpegurl")
("sid","audio/prs.sid")
("aif","audio/x-aiff")
("aiff","audio/x-aiff")
("aifc","audio/x-aiff")
("gsm","audio/x-gsm")
("m3u","audio/x-mpegurl")
("wma","audio/x-ms-wma")
("wax","audio/x-ms-wax")
("ra","audio/x-pn-realaudio")
("rm","audio/x-pn-realaudio")
("ram","audio/x-pn-realaudio")
("ra","audio/x-realaudio")
("pls","audio/x-scpls")
("sd2","audio/x-sd2")
("wav","audio/x-wav")
("bmp","image/bmp")
("qcp","audio/x-qcp")
("gif","image/gif")
("cur","image/ico")
("ico","image/ico")
("ief","image/ief")
("jpeg","image/jpeg")
("jpg","image/jpeg")
("jpe","image/jpeg")
("pcx","image/pcx")
("png","image/png")
("svg","image/svg+xml")
("svgz","image/svg+xml")
("tiff","image/tiff")
("tif","image/tiff")
("djvu","image/vnd.djvu")
("djv","image/vnd.djvu")
("wbmp","image/vnd.wap.wbmp")
("ras","image/x-cmu-raster")
("cdr","image/x-coreldraw")
("pat","image/x-coreldrawpattern")
("cdt","image/x-coreldrawtemplate")
("cpt","image/x-corelphotopaint")
("ico","image/x-icon")
("art","image/x-jg")
("jng","image/x-jng")
("bmp","image/x-ms-bmp")
("psd","image/x-photoshop")
("pnm","image/x-portable-anymap")
("pbm","image/x-portable-bitmap")
("pgm","image/x-portable-graymap")
("ppm","image/x-portable-pixmap")
("rgb","image/x-rgb")
("xbm","image/x-xbitmap")
("xpm","image/x-xpixmap")
("xwd","image/x-xwindowdump")
("igs","model/iges")
("iges","model/iges")
("msh","model/mesh")
("mesh","model/mesh")
("silo","model/mesh")
("ics","text/calendar")
("icz","text/calendar")
("csv","text/comma-separated-values")
("css","text/css")
("htm","text/html")
("html","text/html")
("323","text/h323")
("uls","text/iuls")
("mml","text/mathml")
("txt","text/plain")
("asc","text/plain")
("text","text/plain")
("diff","text/plain")
("po","text/plain")
("rtx","text/richtext")
("rtf","text/rtf")
("ts","text/texmacs")
("phps","text/text")
("tsv","text/tab-separated-values")
("xml","text/xml")
("bib","text/x-bibtex")
("boo","text/x-boo")
("h++","text/x-c++hdr")
("hpp","text/x-c++hdr")
("hxx","text/x-c++hdr")
("hh","text/x-c++hdr")
("c++","text/x-c++src")
("cpp","text/x-c++src")
("cxx","text/x-c++src")
("h","text/x-chdr")
("htc","text/x-component")
("csh","text/x-csh")
("c","text/x-csrc")
("d","text/x-dsrc")
("hs","text/x-haskell")
("java","text/x-java")
("lhs","text/x-literate-haskell")
("moc","text/x-moc")
("p","text/x-pascal")
("pas","text/x-pascal")
("gcd","text/x-pcs-gcd")
("etx","text/x-setext")
("tcl","text/x-tcl")
("tex","text/x-tex")
("ltx","text/x-tex")
("sty","text/x-tex")
("cls","text/x-tex")
("vcs","text/x-vcalendar")
("vcf","text/x-vcard")
("3gpp","video/3gpp")
("3gp","video/3gpp")
("3g2","video/3gpp")
("dl","video/dl")
("dif","video/dv")
("dv","video/dv")
("fli","video/fli")
("m4v","video/m4v")
("mpeg","video/mpeg")
("mpg","video/mpeg")
("mpe","video/mpeg")
("mp4","video/mp4")
("vob","video/mpeg")
("qt","video/quicktime")
("mov","video/quicktime")
("mxu","video/vnd.mpegurl")
("webm","video/webm")
("lsf","video/x-la-asf")
("lsx","video/x-la-asf")
("mng","video/x-mng")
("asf","video/x-ms-asf")
("asx","video/x-ms-asf")
("wm","video/x-ms-wm")
("wmv","video/x-ms-wmv")
("wmx","video/x-ms-wmx")
("wvx","video/x-ms-wvx")
("avi","video/x-msvideo")
("movie","video/x-sgi-movie")
("ice","x-conference/x-cooltalk")
("sisx","x-epoc/x-sisx-app")
提问：同一个后缀名对应多个MIME值是什么情况，怎么解释。希望有明白的能留言交流。
