更新
多くの貢献者からの追加を含む最新のマッピングについては、次のGitHubリポジトリを参照してください。
https://github.com/samuelneff/MimeTypeMap
アプリケーションが使用する多くのMIMEタイプがデフォルトのWindowsレジストリにないこと、他のMIMEタイプがレジストリにあるがIISに含まれているリストにはないことを発見しました。これらの場所からリストを作成し、使用する他のいくつかを追加しました。
編集：効率的で確定的な双方向マッピングを含む、ここでの貢献を含む最新バージョンを参照してください。
private static IDictionary<string, string> _mappings = new Dictionary<string, string>(StringComparer.InvariantCultureIgnoreCase) {
#region Big freaking list of mime types
// combination of values from Windows 7 Registry and
// from C:\Windows\System32\inetsrv\config\applicationHost.config
// some added, including .7z and .dat
{".323", "text/h323"},
{".3g2", "video/3gpp2"},
{".3gp", "video/3gpp"},
{".3gp2", "video/3gpp2"},
{".3gpp", "video/3gpp"},
{".7z", "application/x-7z-compressed"},
{".aa", "audio/audible"},
{".AAC", "audio/aac"},
{".aaf", "application/octet-stream"},
{".aax", "audio/vnd.audible.aax"},
{".ac3", "audio/ac3"},
{".aca", "application/octet-stream"},
{".accda", "application/msaccess.addin"},
{".accdb", "application/msaccess"},
{".accdc", "application/msaccess.cab"},
{".accde", "application/msaccess"},
{".accdr", "application/msaccess.runtime"},
{".accdt", "application/msaccess"},
{".accdw", "application/msaccess.webapplication"},
{".accft", "application/msaccess.ftemplate"},
{".acx", "application/internet-property-stream"},
{".AddIn", "text/xml"},
{".ade", "application/msaccess"},
{".adobebridge", "application/x-bridge-url"},
{".adp", "application/msaccess"},
{".ADT", "audio/vnd.dlna.adts"},
{".ADTS", "audio/aac"},
{".afm", "application/octet-stream"},
{".ai", "application/postscript"},
{".aif", "audio/x-aiff"},
{".aifc", "audio/aiff"},
{".aiff", "audio/aiff"},
{".air", "application/vnd.adobe.air-application-installer-package+zip"},
{".amc", "application/x-mpeg"},
{".application", "application/x-ms-application"},
{".art", "image/x-jg"},
{".asa", "application/xml"},
{".asax", "application/xml"},
{".ascx", "application/xml"},
{".asd", "application/octet-stream"},
{".asf", "video/x-ms-asf"},
{".ashx", "application/xml"},
{".asi", "application/octet-stream"},
{".asm", "text/plain"},
{".asmx", "application/xml"},
{".aspx", "application/xml"},
{".asr", "video/x-ms-asf"},
{".asx", "video/x-ms-asf"},
{".atom", "application/atom+xml"},
{".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"},
{".cab", "application/octet-stream"},
{".caf", "audio/x-caf"},
{".calx", "application/vnd.ms-office.calx"},
{".cat", "application/vnd.ms-pki.seccat"},
{".cc", "text/plain"},
{".cd", "text/plain"},
{".cdda", "audio/aiff"},
{".cdf", "application/x-cdf"},
{".cer", "application/x-x509-ca-cert"},
{".chm", "application/octet-stream"},
{".class", "application/x-java-applet"},
{".clp", "application/x-msclip"},
{".cmx", "image/x-cmx"},
{".cnf", "text/plain"},
{".cod", "image/cis-cod"},
{".config", "application/xml"},
{".contact", "text/x-ms-contact"},
{".coverage", "application/xml"},
{".cpio", "application/x-cpio"},
{".cpp", "text/plain"},
{".crd", "application/x-mscardfile"},
{".crl", "application/pkix-crl"},
{".crt", "application/x-x509-ca-cert"},
{".cs", "text/plain"},
{".csdproj", "text/plain"},
{".csh", "application/x-csh"},
{".csproj", "text/plain"},
{".css", "text/css"},
{".csv", "text/csv"},
{".cur", "application/octet-stream"},
{".cxx", "text/plain"},
{".dat", "application/octet-stream"},
{".datasource", "application/xml"},
{".dbproj", "text/plain"},
{".dcr", "application/x-director"},
{".def", "text/plain"},
{".deploy", "application/octet-stream"},
{".der", "application/x-x509-ca-cert"},
{".dgml", "application/xml"},
{".dib", "image/bmp"},
{".dif", "video/x-dv"},
{".dir", "application/x-director"},
{".disco", "text/xml"},
{".dll", "application/x-msdownload"},
{".dll.config", "text/xml"},
{".dlm", "text/dlm"},
{".doc", "application/msword"},
{".docm", "application/vnd.ms-word.document.macroEnabled.12"},
{".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
{".dot", "application/msword"},
{".dotm", "application/vnd.ms-word.template.macroEnabled.12"},
{".dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template"},
{".dsp", "application/octet-stream"},
{".dsw", "text/plain"},
{".dtd", "text/xml"},
{".dtsConfig", "text/xml"},
{".dv", "video/x-dv"},
{".dvi", "application/x-dvi"},
{".dwf", "drawing/x-dwf"},
{".dwp", "application/octet-stream"},
{".dxr", "application/x-director"},
{".eml", "message/rfc822"},
{".emz", "application/octet-stream"},
{".eot", "application/octet-stream"},
{".eps", "application/postscript"},
{".etl", "application/etl"},
{".etx", "text/x-setext"},
{".evy", "application/envoy"},
{".exe", "application/octet-stream"},
{".exe.config", "text/xml"},
{".fdf", "application/vnd.fdf"},
{".fif", "application/fractals"},
{".filters", "Application/xml"},
{".fla", "application/octet-stream"},
{".flr", "x-world/x-vrml"},
{".flv", "video/x-flv"},
{".fsscript", "application/fsharp-script"},
{".fsx", "application/fsharp-script"},
{".generictest", "application/xml"},
{".gif", "image/gif"},
{".group", "text/x-ms-group"},
{".gsm", "audio/x-gsm"},
{".gtar", "application/x-gtar"},
{".gz", "application/x-gzip"},
{".h", "text/plain"},
{".hdf", "application/x-hdf"},
{".hdml", "text/x-hdml"},
{".hhc", "application/x-oleobject"},
{".hhk", "application/octet-stream"},
{".hhp", "application/octet-stream"},
{".hlp", "application/winhlp"},
{".hpp", "text/plain"},
{".hqx", "application/mac-binhex40"},
{".hta", "application/hta"},
{".htc", "text/x-component"},
{".htm", "text/html"},
{".html", "text/html"},
{".htt", "text/webviewhtml"},
{".hxa", "application/xml"},
{".hxc", "application/xml"},
{".hxd", "application/octet-stream"},
{".hxe", "application/xml"},
{".hxf", "application/xml"},
{".hxh", "application/octet-stream"},
{".hxi", "application/octet-stream"},
{".hxk", "application/xml"},
{".hxq", "application/octet-stream"},
{".hxr", "application/octet-stream"},
{".hxs", "application/octet-stream"},
{".hxt", "text/html"},
{".hxv", "application/xml"},
{".hxw", "application/octet-stream"},
{".hxx", "text/plain"},
{".i", "text/plain"},
{".ico", "image/x-icon"},
{".ics", "application/octet-stream"},
{".idl", "text/plain"},
{".ief", "image/ief"},
{".iii", "application/x-iphone"},
{".inc", "text/plain"},
{".inf", "application/octet-stream"},
{".inl", "text/plain"},
{".ins", "application/x-internet-signup"},
{".ipa", "application/x-itunes-ipa"},
{".ipg", "application/x-itunes-ipg"},
{".ipproj", "text/plain"},
{".ipsw", "application/x-itunes-ipsw"},
{".iqy", "text/x-ms-iqy"},
{".isp", "application/x-internet-signup"},
{".ite", "application/x-itunes-ite"},
{".itlp", "application/x-itunes-itlp"},
{".itms", "application/x-itunes-itms"},
{".itpc", "application/x-itunes-itpc"},
{".IVF", "video/x-ivf"},
{".jar", "application/java-archive"},
{".java", "application/octet-stream"},
{".jck", "application/liquidmotion"},
{".jcz", "application/liquidmotion"},
{".jfif", "image/pjpeg"},
{".jnlp", "application/x-java-jnlp-file"},
{".jpb", "application/octet-stream"},
{".jpe", "image/jpeg"},
{".jpeg", "image/jpeg"},
{".jpg", "image/jpeg"},
{".js", "application/x-javascript"},
{".json", "application/json"},
{".jsx", "text/jscript"},
{".jsxbin", "text/plain"},
{".latex", "application/x-latex"},
{".library-ms", "application/windows-library+xml"},
{".lit", "application/x-ms-reader"},
{".loadtest", "application/xml"},
{".lpk", "application/octet-stream"},
{".lsf", "video/x-la-asf"},
{".lst", "text/plain"},
{".lsx", "video/x-la-asf"},
{".lzh", "application/octet-stream"},
{".m13", "application/x-msmediaview"},
{".m14", "application/x-msmediaview"},
{".m1v", "video/mpeg"},
{".m2t", "video/vnd.dlna.mpeg-tts"},
{".m2ts", "video/vnd.dlna.mpeg-tts"},
{".m2v", "video/mpeg"},
{".m3u", "audio/x-mpegurl"},
{".m3u8", "audio/x-mpegurl"},
{".m4a", "audio/m4a"},
{".m4b", "audio/m4b"},
{".m4p", "audio/m4p"},
{".m4r", "audio/x-m4r"},
{".m4v", "video/x-m4v"},
{".mac", "image/x-macpaint"},
{".mak", "text/plain"},
{".man", "application/x-troff-man"},
{".manifest", "application/x-ms-manifest"},
{".map", "text/plain"},
{".master", "application/xml"},
{".mda", "application/msaccess"},
{".mdb", "application/x-msaccess"},
{".mde", "application/msaccess"},
{".mdp", "application/octet-stream"},
{".me", "application/x-troff-me"},
{".mfp", "application/x-shockwave-flash"},
{".mht", "message/rfc822"},
{".mhtml", "message/rfc822"},
{".mid", "audio/mid"},
{".midi", "audio/mid"},
{".mix", "application/octet-stream"},
{".mk", "text/plain"},
{".mmf", "application/x-smaf"},
{".mno", "text/xml"},
{".mny", "application/x-msmoney"},
{".mod", "video/mpeg"},
{".mov", "video/quicktime"},
{".movie", "video/x-sgi-movie"},
{".mp2", "video/mpeg"},
{".mp2v", "video/mpeg"},
{".mp3", "audio/mpeg"},
{".mp4", "video/mp4"},
{".mp4v", "video/mp4"},
{".mpa", "video/mpeg"},
{".mpe", "video/mpeg"},
{".mpeg", "video/mpeg"},
{".mpf", "application/vnd.ms-mediapackage"},
{".mpg", "video/mpeg"},
{".mpp", "application/vnd.ms-project"},
{".mpv2", "video/mpeg"},
{".mqv", "video/quicktime"},
{".ms", "application/x-troff-ms"},
{".msi", "application/octet-stream"},
{".mso", "application/octet-stream"},
{".mts", "video/vnd.dlna.mpeg-tts"},
{".mtx", "application/xml"},
{".mvb", "application/x-msmediaview"},
{".mvc", "application/x-miva-compiled"},
{".mxp", "application/x-mmxp"},
{".nc", "application/x-netcdf"},
{".nsc", "video/x-ms-asf"},
{".nws", "message/rfc822"},
{".ocx", "application/octet-stream"},
{".oda", "application/oda"},
{".odc", "text/x-ms-odc"},
{".odh", "text/plain"},
{".odl", "text/plain"},
{".odp", "application/vnd.oasis.opendocument.presentation"},
{".ods", "application/oleobject"},
{".odt", "application/vnd.oasis.opendocument.text"},
{".one", "application/onenote"},
{".onea", "application/onenote"},
{".onepkg", "application/onenote"},
{".onetmp", "application/onenote"},
{".onetoc", "application/onenote"},
{".onetoc2", "application/onenote"},
{".orderedtest", "application/xml"},
{".osdx", "application/opensearchdescription+xml"},
{".p10", "application/pkcs10"},
{".p12", "application/x-pkcs12"},
{".p7b", "application/x-pkcs7-certificates"},
{".p7c", "application/pkcs7-mime"},
{".p7m", "application/pkcs7-mime"},
{".p7r", "application/x-pkcs7-certreqresp"},
{".p7s", "application/pkcs7-signature"},
{".pbm", "image/x-portable-bitmap"},
{".pcast", "application/x-podcast"},
{".pct", "image/pict"},
{".pcx", "application/octet-stream"},
{".pcz", "application/octet-stream"},
{".pdf", "application/pdf"},
{".pfb", "application/octet-stream"},
{".pfm", "application/octet-stream"},
{".pfx", "application/x-pkcs12"},
{".pgm", "image/x-portable-graymap"},
{".pic", "image/pict"},
{".pict", "image/pict"},
{".pkgdef", "text/plain"},
{".pkgundef", "text/plain"},
{".pko", "application/vnd.ms-pki.pko"},
{".pls", "audio/scpls"},
{".pma", "application/x-perfmon"},
{".pmc", "application/x-perfmon"},
{".pml", "application/x-perfmon"},
{".pmr", "application/x-perfmon"},
{".pmw", "application/x-perfmon"},
{".png", "image/png"},
{".pnm", "image/x-portable-anymap"},
{".pnt", "image/x-macpaint"},
{".pntg", "image/x-macpaint"},
{".pnz", "image/png"},
{".pot", "application/vnd.ms-powerpoint"},
{".potm", "application/vnd.ms-powerpoint.template.macroEnabled.12"},
{".potx", "application/vnd.openxmlformats-officedocument.presentationml.template"},
{".ppa", "application/vnd.ms-powerpoint"},
{".ppam", "application/vnd.ms-powerpoint.addin.macroEnabled.12"},
{".ppm", "image/x-portable-pixmap"},
{".pps", "application/vnd.ms-powerpoint"},
{".ppsm", "application/vnd.ms-powerpoint.slideshow.macroEnabled.12"},
{".ppsx", "application/vnd.openxmlformats-officedocument.presentationml.slideshow"},
{".ppt", "application/vnd.ms-powerpoint"},
{".pptm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12"},
{".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
{".prf", "application/pics-rules"},
{".prm", "application/octet-stream"},
{".prx", "application/octet-stream"},
{".ps", "application/postscript"},
{".psc1", "application/PowerShell"},
{".psd", "application/octet-stream"},
{".psess", "application/xml"},
{".psm", "application/octet-stream"},
{".psp", "application/octet-stream"},
{".pub", "application/x-mspublisher"},
{".pwz", "application/vnd.ms-powerpoint"},
{".qht", "text/x-html-insertion"},
{".qhtm", "text/x-html-insertion"},
{".qt", "video/quicktime"},
{".qti", "image/x-quicktime"},
{".qtif", "image/x-quicktime"},
{".qtl", "application/x-quicktimeplayer"},
{".qxd", "application/octet-stream"},
{".ra", "audio/x-pn-realaudio"},
{".ram", "audio/x-pn-realaudio"},
{".rar", "application/octet-stream"},
{".ras", "image/x-cmu-raster"},
{".rat", "application/rat-file"},
{".rc", "text/plain"},
{".rc2", "text/plain"},
{".rct", "text/plain"},
{".rdlc", "application/xml"},
{".resx", "application/xml"},
{".rf", "image/vnd.rn-realflash"},
{".rgb", "image/x-rgb"},
{".rgs", "text/plain"},
{".rm", "application/vnd.rn-realmedia"},
{".rmi", "audio/mid"},
{".rmp", "application/vnd.rn-rn_music_package"},
{".roff", "application/x-troff"},
{".rpm", "audio/x-pn-realaudio-plugin"},
{".rqy", "text/x-ms-rqy"},
{".rtf", "application/rtf"},
{".rtx", "text/richtext"},
{".ruleset", "application/xml"},
{".s", "text/plain"},
{".safariextz", "application/x-safari-safariextz"},
{".scd", "application/x-msschedule"},
{".sct", "text/scriptlet"},
{".sd2", "audio/x-sd2"},
{".sdp", "application/sdp"},
{".sea", "application/octet-stream"},
{".searchConnector-ms", "application/windows-search-connector+xml"},
{".setpay", "application/set-payment-initiation"},
{".setreg", "application/set-registration-initiation"},
{".settings", "application/xml"},
{".sgimb", "application/x-sgimb"},
{".sgml", "text/sgml"},
{".sh", "application/x-sh"},
{".shar", "application/x-shar"},
{".shtml", "text/html"},
{".sit", "application/x-stuffit"},
{".sitemap", "application/xml"},
{".skin", "application/xml"},
{".sldm", "application/vnd.ms-powerpoint.slide.macroEnabled.12"},
{".sldx", "application/vnd.openxmlformats-officedocument.presentationml.slide"},
{".slk", "application/vnd.ms-excel"},
{".sln", "text/plain"},
{".slupkg-ms", "application/x-ms-license"},
{".smd", "audio/x-smd"},
{".smi", "application/octet-stream"},
{".smx", "audio/x-smd"},
{".smz", "audio/x-smd"},
{".snd", "audio/basic"},
{".snippet", "application/xml"},
{".snp", "application/octet-stream"},
{".sol", "text/plain"},
{".sor", "text/plain"},
{".spc", "application/x-pkcs7-certificates"},
{".spl", "application/futuresplash"},
{".src", "application/x-wais-source"},
{".srf", "text/plain"},
{".SSISDeploymentManifest", "text/xml"},
{".ssm", "application/streamingmedia"},
{".sst", "application/vnd.ms-pki.certstore"},
{".stl", "application/vnd.ms-pki.stl"},
{".sv4cpio", "application/x-sv4cpio"},
{".sv4crc", "application/x-sv4crc"},
{".svc", "application/xml"},
{".swf", "application/x-shockwave-flash"},
{".t", "application/x-troff"},
{".tar", "application/x-tar"},
{".tcl", "application/x-tcl"},
{".testrunconfig", "application/xml"},
{".testsettings", "application/xml"},
{".tex", "application/x-tex"},
{".texi", "application/x-texinfo"},
{".texinfo", "application/x-texinfo"},
{".tgz", "application/x-compressed"},
{".thmx", "application/vnd.ms-officetheme"},
{".thn", "application/octet-stream"},
{".tif", "image/tiff"},
{".tiff", "image/tiff"},
{".tlh", "text/plain"},
{".tli", "text/plain"},
{".toc", "application/octet-stream"},
{".tr", "application/x-troff"},
{".trm", "application/x-msterminal"},
{".trx", "application/xml"},
{".ts", "video/vnd.dlna.mpeg-tts"},
{".tsv", "text/tab-separated-values"},
{".ttf", "application/octet-stream"},
{".tts", "video/vnd.dlna.mpeg-tts"},
{".txt", "text/plain"},
{".u32", "application/octet-stream"},
{".uls", "text/iuls"},
{".user", "text/plain"},
{".ustar", "application/x-ustar"},
{".vb", "text/plain"},
{".vbdproj", "text/plain"},
{".vbk", "video/mpeg"},
{".vbproj", "text/plain"},
{".vbs", "text/vbscript"},
{".vcf", "text/x-vcard"},
{".vcproj", "Application/xml"},
{".vcs", "text/plain"},
{".vcxproj", "Application/xml"},
{".vddproj", "text/plain"},
{".vdp", "text/plain"},
{".vdproj", "text/plain"},
{".vdx", "application/vnd.ms-visio.viewer"},
{".vml", "text/xml"},
{".vscontent", "application/xml"},
{".vsct", "text/xml"},
{".vsd", "application/vnd.visio"},
{".vsi", "application/ms-vsi"},
{".vsix", "application/vsix"},
{".vsixlangpack", "text/xml"},
{".vsixmanifest", "text/xml"},
{".vsmdi", "application/xml"},
{".vspscc", "text/plain"},
{".vss", "application/vnd.visio"},
{".vsscc", "text/plain"},
{".vssettings", "text/xml"},
{".vssscc", "text/plain"},
{".vst", "application/vnd.visio"},
{".vstemplate", "text/xml"},
{".vsto", "application/x-ms-vsto"},
{".vsw", "application/vnd.visio"},
{".vsx", "application/vnd.visio"},
{".vtx", "application/vnd.visio"},
{".wav", "audio/wav"},
{".wave", "audio/wav"},
{".wax", "audio/x-ms-wax"},
{".wbk", "application/msword"},
{".wbmp", "image/vnd.wap.wbmp"},
{".wcm", "application/vnd.ms-works"},
{".wdb", "application/vnd.ms-works"},
{".wdp", "image/vnd.ms-photo"},
{".webarchive", "application/x-safari-webarchive"},
{".webtest", "application/xml"},
{".wiq", "application/xml"},
{".wiz", "application/msword"},
{".wks", "application/vnd.ms-works"},
{".WLMP", "application/wlmoviemaker"},
{".wlpginstall", "application/x-wlpg-detect"},
{".wlpginstall3", "application/x-wlpg3-detect"},
{".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"},
{".wmp", "video/x-ms-wmp"},
{".wmv", "video/x-ms-wmv"},
{".wmx", "video/x-ms-wmx"},
{".wmz", "application/x-ms-wmz"},
{".wpl", "application/vnd.ms-wpl"},
{".wps", "application/vnd.ms-works"},
{".wri", "application/x-mswrite"},
{".wrl", "x-world/x-vrml"},
{".wrz", "x-world/x-vrml"},
{".wsc", "text/scriptlet"},
{".wsdl", "text/xml"},
{".wvx", "video/x-ms-wvx"},
{".x", "application/directx"},
{".xaf", "x-world/x-vrml"},
{".xaml", "application/xaml+xml"},
{".xap", "application/x-silverlight-app"},
{".xbap", "application/x-ms-xbap"},
{".xbm", "image/x-xbitmap"},
{".xdr", "text/plain"},
{".xht", "application/xhtml+xml"},
{".xhtml", "application/xhtml+xml"},
{".xla", "application/vnd.ms-excel"},
{".xlam", "application/vnd.ms-excel.addin.macroEnabled.12"},
{".xlc", "application/vnd.ms-excel"},
{".xld", "application/vnd.ms-excel"},
{".xlk", "application/vnd.ms-excel"},
{".xll", "application/vnd.ms-excel"},
{".xlm", "application/vnd.ms-excel"},
{".xls", "application/vnd.ms-excel"},
{".xlsb", "application/vnd.ms-excel.sheet.binary.macroEnabled.12"},
{".xlsm", "application/vnd.ms-excel.sheet.macroEnabled.12"},
{".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
{".xlt", "application/vnd.ms-excel"},
{".xltm", "application/vnd.ms-excel.template.macroEnabled.12"},
{".xltx", "application/vnd.openxmlformats-officedocument.spreadsheetml.template"},
{".xlw", "application/vnd.ms-excel"},
{".xml", "text/xml"},
{".xmta", "application/xml"},
{".xof", "x-world/x-vrml"},
{".XOML", "text/plain"},
{".xpm", "image/x-xpixmap"},
{".xps", "application/vnd.ms-xpsdocument"},
{".xrm-ms", "text/xml"},
{".xsc", "application/xml"},
{".xsd", "text/xml"},
{".xsf", "text/xml"},
{".xsl", "text/xml"},
{".xslt", "text/xml"},
{".xsn", "application/octet-stream"},
{".xss", "application/xml"},
{".xtp", "application/octet-stream"},
{".xwd", "image/x-xwindowdump"},
{".z", "application/x-compress"},
{".zip", "application/x-zip-compressed"},
#endregion
};
public static string GetMimeType(string extension)
{
if (extension == null)
{
throw new ArgumentNullException("extension");
}
if (!extension.StartsWith("."))
{
extension = "." + extension;
}
string mime;
return _mappings.TryGetValue(extension, out mime) ? mime : "application/octet-stream";
}
