Estensioni di file e tipi MIME in .NET
https://stackoverflow.com/questions/1612767
-
06-07-2019 - |
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Voglio ottenere un tipo di contenuto MIME da una determinata estensione (preferibilmente senza accedere al file fisico). Ho visto alcune domande al riguardo e i metodi descritti per eseguire questa operazione possono essere ripresi in:
- Utilizza informazioni sul registro .
- Usa FindMimeFromData di urlmon.dll .
- Utilizza Informazioni IIS .
- Crea la tua funzione di mappatura MIME. Basato su questa tabella , per esempio.
Sto usando il n. 1 da qualche tempo ma mi sono reso conto che le informazioni fornite dal registro non sono coerenti e dipendono dal software installato sulla macchina. Alcune estensioni, come .zip, non utilizzano un tipo di contenuto specificato.
La soluzione n. 2 mi obbliga ad avere il file su disco per leggere i primi byte, che è qualcosa di lento ma che può ottenere buoni risultati.
Il terzo metodo si basa sui servizi di directory e tutto il resto, cosa che non mi piace molto perché devo aggiungere riferimenti COM e non sono sicuro che sia coerente tra IIS6 e IIS7. Inoltre, non conosco le prestazioni di questo metodo.
Infine, non volevo usare il mio tavolo, ma alla fine sembra l'opzione migliore se desidero prestazioni decenti e coerenza dei risultati tra le piattaforme (anche Mono).
Pensi che ci sia un'opzione migliore rispetto all'utilizzo della mia tabella o che uno degli altri metodi descritti sia migliore? Qual è la tua esperienza?
Soluzione
Dipende da cosa ti serve il tipo MIME. In generale, per i servizi (app Web, servizio Web, ecc.), È consigliabile non utilizzare un elenco MIME che dipende dalle impostazioni del sistema operativo o solo come fallback se non è possibile trovare altrimenti informazioni MIME.
Penso che questo sia anche il motivo per cui MS ha scelto di inserire tipi MIME costanti nella loro classe System.Web.MimeMapping (purtroppo è interna, per qualunque motivo).
Modifica:
Wrapper (< = .NET 3.5)
public static class MimeExtensionHelper
{
static object locker = new object();
static object mimeMapping;
static MethodInfo getMimeMappingMethodInfo;
static MimeExtensionHelper()
{
Type mimeMappingType = Assembly.GetAssembly(typeof(HttpRuntime)).GetType("System.Web.MimeMapping");
if (mimeMappingType == null)
throw new SystemException("Couldnt find MimeMapping type");
ConstructorInfo constructorInfo = mimeMappingType.GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, Type.EmptyTypes, null);
if (constructorInfo == null)
throw new SystemException("Couldnt find default constructor for MimeMapping");
mimeMapping = constructorInfo.Invoke(null);
if (mimeMapping == null)
throw new SystemException("Couldnt find MimeMapping");
getMimeMappingMethodInfo = mimeMappingType.GetMethod("GetMimeMapping", BindingFlags.Static | BindingFlags.NonPublic);
if (getMimeMappingMethodInfo == null)
throw new SystemException("Couldnt find GetMimeMapping method");
if (getMimeMappingMethodInfo.ReturnType != typeof(string))
throw new SystemException("GetMimeMapping method has invalid return type");
if (getMimeMappingMethodInfo.GetParameters().Length != 1 && getMimeMappingMethodInfo.GetParameters()[0].ParameterType != typeof(string))
throw new SystemException("GetMimeMapping method has invalid parameters");
}
public static string GetMimeType(string filename)
{
lock (locker)
return (string)getMimeMappingMethodInfo.Invoke(mimeMapping, new object[] { filename });
}
}
Wrapper (.NET 4.0)
public static class MimeExtensionHelper
{
static object locker = new object();
static object mimeMapping;
static MethodInfo getMimeMappingMethodInfo;
static MimeExtensionHelper()
{
Type mimeMappingType = Assembly.GetAssembly(typeof(HttpRuntime)).GetType("System.Web.MimeMapping");
if (mimeMappingType == null)
throw new SystemException("Couldnt find MimeMapping type");
getMimeMappingMethodInfo = mimeMappingType.GetMethod("GetMimeMapping", BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public);
if (getMimeMappingMethodInfo == null)
throw new SystemException("Couldnt find GetMimeMapping method");
if (getMimeMappingMethodInfo.ReturnType != typeof(string))
throw new SystemException("GetMimeMapping method has invalid return type");
if (getMimeMappingMethodInfo.GetParameters().Length != 1 && getMimeMappingMethodInfo.GetParameters()[0].ParameterType != typeof(string))
throw new SystemException("GetMimeMapping method has invalid parameters");
}
public static string GetMimeType(string filename)
{
lock (locker)
return (string)getMimeMappingMethodInfo.Invoke(mimeMapping, new object[] { filename });
}
}
.NET 4.5+
Nessun wrapper richiesto, chiama il metodo pubblico System.Web.MimeMapping.GetMimeMapping direttamente.
Altri suggerimenti
Ho combinato tutti questi approcci nella mia utility lib, tranne forse n. 3. A proposito, n. 2 (urlmon.dll) non richiede file statici, richiede semplicemente alcuni byte, indipendentemente da dove siano venuti. Ecco la mia classe attuale
namespace Components
{
using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;
using System.Xml.Serialization;
using Microsoft.Win32;
public sealed class MimeExtensionHelper
{
private MimeExtensionHelper() { }
/// <summary>Finds extension associated with specified mime type</summary>
/// <param name="mimeType">mime type you search extension for, e.g.: "application/octet-stream"</param>
/// <returns>most used extension, associated with provided type, e.g.: ".bin"</returns>
public static string FindExtension(string mimeType)
{
return ExtensionTypes.GetExtension(mimeType);
}
/// <summary>Finds mime type using provided extension and/or file's binary content.</summary>
/// <param name="file">Full file path</param>
/// <param name="verifyFromContent">Should the file's content be examined to verify founded value.</param>
/// <returns>mime type of file, e.g.: "application/octet-stream"</returns>
public static string FindMime(string file,bool verifyFromContent)
{
string extension = Path.GetExtension(file);
string mimeType = string.Empty;
try
{
if (!String.IsNullOrEmpty(extension))
mimeType = ExtensionTypes.GetMimeType(extension);
if (verifyFromContent
|| (String.IsNullOrEmpty(mimeType) && File.Exists(file)))
mimeType = FindMimeByContent(file,mimeType);
}
catch { }
return (mimeType ?? string.Empty).Trim();//"application/octet-stream"
}
/// <summary>Finds mime type for file using it's binary data.</summary>
/// <param name="file">Full path to file.</param>
/// <param name="proposedType">Optional. Expected file's type.</param>
/// <returns>mime type, e.g.: "application/octet-stream"</returns>
public static string FindMimeByContent(string file
,string proposedType)
{
FileInfo fi = new FileInfo(file);
if (!fi.Exists)
throw new FileNotFoundException(file);
byte[] buf = new byte[Math.Min(4096L,fi.Length)];
using (FileStream fs = File.OpenRead(file))
fs.Read(buf,0,buf.Length);
return FindMimeByData(buf,proposedType);
}
/// <summary>Finds mime type for binary data.</summary>
/// <param name="dataBytes">Binary data to examine.</param>
/// <param name="mimeProposed">Optional. Expected mime type.</param>
/// <returns>mime type, e.g.: "application/octet-stream"</returns>
public static string FindMimeByData(byte[] dataBytes,string mimeProposed)
{
if (dataBytes == null || dataBytes.Length == 0)
throw new ArgumentNullException("dataBytes");
string mimeRet = String.Empty;
IntPtr outPtr = IntPtr.Zero;
if (!String.IsNullOrEmpty(mimeProposed))
mimeRet = mimeProposed;
int result = FindMimeFromData(IntPtr.Zero
,null
,dataBytes
,dataBytes.Length
,String.IsNullOrEmpty(mimeProposed) ? null : mimeProposed
,0
,out outPtr
,0);
if (result != 0)
throw Marshal.GetExceptionForHR(result);
if (outPtr != null && outPtr != IntPtr.Zero)
{
mimeRet = Marshal.PtrToStringUni(outPtr);
Marshal.FreeCoTaskMem(outPtr);
}
return mimeRet;
}
[DllImport("urlmon.dll"
,CharSet = CharSet.Unicode
,ExactSpelling = true
,SetLastError = true)]
static extern Int32 FindMimeFromData(IntPtr pBC
,[MarshalAs(UnmanagedType.LPWStr)] String pwzUrl
,[MarshalAs(UnmanagedType.LPArray,ArraySubType = UnmanagedType.I1,SizeParamIndex = 3)] Byte[] pBuffer
,Int32 cbSize
,[MarshalAs(UnmanagedType.LPWStr)] String pwzMimeProposed
,Int32 dwMimeFlags
,out IntPtr ppwzMimeOut
,Int32 dwReserved);
private static MimeTypeCollection _extensionTypes = null;
private static MimeTypeCollection ExtensionTypes
{
get
{
if (_extensionTypes == null)
_extensionTypes = new MimeTypeCollection();
return _extensionTypes;
}
}
[Serializable]
[XmlRoot(ElementName = "mimeTypes")]
private class MimeTypeCollection : List<MimeTypeCollection.mimeTypeInfo>
{
private SortedList<string,string> _extensions;
private SortedList<string,List<string>> _mimes;
private void Init()
{
if (_extensions == null || _mimes == null
|| _extensions.Count == 0 || _mimes.Count == 0)
{
_extensions = new SortedList<string,string>(StringComparer.OrdinalIgnoreCase);
_mimes = new SortedList<string,List<string>>(StringComparer.OrdinalIgnoreCase);
foreach (var mime in this)
{
_mimes.Add(mime.MimeType,new List<string>(mime.Extensions));
foreach (string ext in mime.Extensions)
if (!_extensions.ContainsKey(ext))
_extensions.Add(ext,mime.MimeType);
}
}
}
public String GetExtension(string type)
{
Init();
return _mimes.ContainsKey(type) ? _mimes[type][0] : string.Empty;
}
public String GetMimeType(string extension)
{
Init();
return _extensions.ContainsKey(extension) ? _extensions[extension] : string.Empty;
}
public MimeTypeCollection()
{
this.Add(new mimeTypeInfo("application/applixware",new List<string>(new[] { ".aw" })));
this.Add(new mimeTypeInfo("application/atom+xml",new List<string>(new[] { ".atom" })));
// ... Whole list from apache's site
this.Add(new mimeTypeInfo("x-x509-ca-cert",new List<string>(new[] { ".cer" })));
try
{
using (RegistryKey classesRoot = Registry.ClassesRoot)
using (RegistryKey typeKey = classesRoot.OpenSubKey(@"MIME\Database\Content Type"))
{
string[] subKeyNames = typeKey.GetSubKeyNames();
string extension = string.Empty;
foreach (string keyname in subKeyNames)
{
string trimmed = (keyname ?? string.Empty).Trim();
if (string.IsNullOrEmpty(trimmed))
continue;
if (!String.IsNullOrEmpty(GetExtension(trimmed)))
continue;
string subKey = "MIME\\Database\\Content Type\\" + trimmed;
using (RegistryKey curKey = classesRoot.OpenSubKey(subKey))
{
extension = (curKey.GetValue("Extension") as string ?? string.Empty).Trim();
if (extension.Length > 0)
this.Add(new mimeTypeInfo(trimmed
,new List<string>(new[] { extension })));
}
}
}
}
catch (Exception ex)
{
string s = ex.ToString();
}
}
[Serializable]
public class mimeTypeInfo
{
[XmlAttribute(AttributeName = "mimeType")]
public String MimeType { get; set; }
[XmlElement("extension")]
public List<String> Extensions { get; set; }
public mimeTypeInfo(string mimeType,List<string> extensions)
{
MimeType = mimeType;
Extensions = extensions;
}
public mimeTypeInfo() { }
}
}
}
}
System.Web.MimeMapping ha 3 versioni: due versioni 4.0 (dove una è interna) e quindi una versione 2.0 anch'essa interna. Come sottolineato, esiste una versione pubblica della classe in System.Web versione 4.0 per il framework .NET 4.5.
Per RoadkillWiki l'ho sostanzialmente invertito per evitare il fastidio di riflettere ogni volta, il gestore di file del Wiki tenta di utilizzare IIS / applicationhost.config per impostazione predefinita, quindi passa alla classe MimeMapping:
private string GetMimeType(string fileExtension, ServerManager serverManager)
{
try
{
string mimeType = "text/plain";
Microsoft.Web.Administration.Configuration config = serverManager.GetApplicationHostConfiguration();
ConfigurationSection staticContentSection = config.GetSection("system.webServer/staticContent");
ConfigurationElementCollection mimemaps = staticContentSection.GetCollection();
ConfigurationElement element = mimemaps.FirstOrDefault(m => m.Attributes["fileExtension"].Value.ToString() == fileExtension);
if (element != null)
mimeType = element.Attributes["mimeType"].Value.ToString();
return mimeType;
}
catch (UnauthorizedAccessException)
{
// Shared hosting won't have access to the applicationhost.config file
return MimeMapping.GetMimeMapping("." +fileExtension);
}
}
E MimeMapping:
public class MimeMapping
{
private static Dictionary<string, string> ExtensionMap = new Dictionary<string, string>();
static MimeMapping()
{
ExtensionMap.Add(".323", "text/h323");
ExtensionMap.Add(".asx", "video/x-ms-asf");
ExtensionMap.Add(".acx", "application/internet-property-stream");
ExtensionMap.Add(".ai", "application/postscript");
ExtensionMap.Add(".aif", "audio/x-aiff");
ExtensionMap.Add(".aiff", "audio/aiff");
ExtensionMap.Add(".axs", "application/olescript");
ExtensionMap.Add(".aifc", "audio/aiff");
ExtensionMap.Add(".asr", "video/x-ms-asf");
ExtensionMap.Add(".avi", "video/x-msvideo");
ExtensionMap.Add(".asf", "video/x-ms-asf");
ExtensionMap.Add(".au", "audio/basic");
ExtensionMap.Add(".application", "application/x-ms-application");
ExtensionMap.Add(".bin", "application/octet-stream");
ExtensionMap.Add(".bas", "text/plain");
ExtensionMap.Add(".bcpio", "application/x-bcpio");
ExtensionMap.Add(".bmp", "image/bmp");
ExtensionMap.Add(".cdf", "application/x-cdf");
ExtensionMap.Add(".cat", "application/vndms-pkiseccat");
ExtensionMap.Add(".crt", "application/x-x509-ca-cert");
ExtensionMap.Add(".c", "text/plain");
ExtensionMap.Add(".css", "text/css");
ExtensionMap.Add(".cer", "application/x-x509-ca-cert");
ExtensionMap.Add(".crl", "application/pkix-crl");
ExtensionMap.Add(".cmx", "image/x-cmx");
ExtensionMap.Add(".csh", "application/x-csh");
ExtensionMap.Add(".cod", "image/cis-cod");
ExtensionMap.Add(".cpio", "application/x-cpio");
ExtensionMap.Add(".clp", "application/x-msclip");
ExtensionMap.Add(".crd", "application/x-mscardfile");
ExtensionMap.Add(".deploy", "application/octet-stream");
ExtensionMap.Add(".dll", "application/x-msdownload");
ExtensionMap.Add(".dot", "application/msword");
ExtensionMap.Add(".doc", "application/msword");
ExtensionMap.Add(".dvi", "application/x-dvi");
ExtensionMap.Add(".dir", "application/x-director");
ExtensionMap.Add(".dxr", "application/x-director");
ExtensionMap.Add(".der", "application/x-x509-ca-cert");
ExtensionMap.Add(".dib", "image/bmp");
ExtensionMap.Add(".dcr", "application/x-director");
ExtensionMap.Add(".disco", "text/xml");
ExtensionMap.Add(".exe", "application/octet-stream");
ExtensionMap.Add(".etx", "text/x-setext");
ExtensionMap.Add(".evy", "application/envoy");
ExtensionMap.Add(".eml", "message/rfc822");
ExtensionMap.Add(".eps", "application/postscript");
ExtensionMap.Add(".flr", "x-world/x-vrml");
ExtensionMap.Add(".fif", "application/fractals");
ExtensionMap.Add(".gtar", "application/x-gtar");
ExtensionMap.Add(".gif", "image/gif");
ExtensionMap.Add(".gz", "application/x-gzip");
ExtensionMap.Add(".hta", "application/hta");
ExtensionMap.Add(".htc", "text/x-component");
ExtensionMap.Add(".htt", "text/webviewhtml");
ExtensionMap.Add(".h", "text/plain");
ExtensionMap.Add(".hdf", "application/x-hdf");
ExtensionMap.Add(".hlp", "application/winhlp");
ExtensionMap.Add(".html", "text/html");
ExtensionMap.Add(".htm", "text/html");
ExtensionMap.Add(".hqx", "application/mac-binhex40");
ExtensionMap.Add(".isp", "application/x-internet-signup");
ExtensionMap.Add(".iii", "application/x-iphone");
ExtensionMap.Add(".ief", "image/ief");
ExtensionMap.Add(".ivf", "video/x-ivf");
ExtensionMap.Add(".ins", "application/x-internet-signup");
ExtensionMap.Add(".ico", "image/x-icon");
ExtensionMap.Add(".jpg", "image/jpeg");
ExtensionMap.Add(".jfif", "image/pjpeg");
ExtensionMap.Add(".jpe", "image/jpeg");
ExtensionMap.Add(".jpeg", "image/jpeg");
ExtensionMap.Add(".js", "application/x-javascript");
ExtensionMap.Add(".lsx", "video/x-la-asf");
ExtensionMap.Add(".latex", "application/x-latex");
ExtensionMap.Add(".lsf", "video/x-la-asf");
ExtensionMap.Add(".manifest", "application/x-ms-manifest");
ExtensionMap.Add(".mhtml", "message/rfc822");
ExtensionMap.Add(".mny", "application/x-msmoney");
ExtensionMap.Add(".mht", "message/rfc822");
ExtensionMap.Add(".mid", "audio/mid");
ExtensionMap.Add(".mpv2", "video/mpeg");
ExtensionMap.Add(".man", "application/x-troff-man");
ExtensionMap.Add(".mvb", "application/x-msmediaview");
ExtensionMap.Add(".mpeg", "video/mpeg");
ExtensionMap.Add(".m3u", "audio/x-mpegurl");
ExtensionMap.Add(".mdb", "application/x-msaccess");
ExtensionMap.Add(".mpp", "application/vnd.ms-project");
ExtensionMap.Add(".m1v", "video/mpeg");
ExtensionMap.Add(".mpa", "video/mpeg");
ExtensionMap.Add(".me", "application/x-troff-me");
ExtensionMap.Add(".m13", "application/x-msmediaview");
ExtensionMap.Add(".movie", "video/x-sgi-movie");
ExtensionMap.Add(".m14", "application/x-msmediaview");
ExtensionMap.Add(".mpe", "video/mpeg");
ExtensionMap.Add(".mp2", "video/mpeg");
ExtensionMap.Add(".mov", "video/quicktime");
ExtensionMap.Add(".mp3", "audio/mpeg");
ExtensionMap.Add(".mpg", "video/mpeg");
ExtensionMap.Add(".ms", "application/x-troff-ms");
ExtensionMap.Add(".nc", "application/x-netcdf");
ExtensionMap.Add(".nws", "message/rfc822");
ExtensionMap.Add(".oda", "application/oda");
ExtensionMap.Add(".ods", "application/oleobject");
ExtensionMap.Add(".pmc", "application/x-perfmon");
ExtensionMap.Add(".p7r", "application/x-pkcs7-certreqresp");
ExtensionMap.Add(".p7b", "application/x-pkcs7-certificates");
ExtensionMap.Add(".p7s", "application/pkcs7-signature");
ExtensionMap.Add(".pmw", "application/x-perfmon");
ExtensionMap.Add(".ps", "application/postscript");
ExtensionMap.Add(".p7c", "application/pkcs7-mime");
ExtensionMap.Add(".pbm", "image/x-portable-bitmap");
ExtensionMap.Add(".ppm", "image/x-portable-pixmap");
ExtensionMap.Add(".pub", "application/x-mspublisher");
ExtensionMap.Add(".pnm", "image/x-portable-anymap");
ExtensionMap.Add(".pml", "application/x-perfmon");
ExtensionMap.Add(".p10", "application/pkcs10");
ExtensionMap.Add(".pfx", "application/x-pkcs12");
ExtensionMap.Add(".p12", "application/x-pkcs12");
ExtensionMap.Add(".pdf", "application/pdf");
ExtensionMap.Add(".pps", "application/vnd.ms-powerpoint");
ExtensionMap.Add(".p7m", "application/pkcs7-mime");
ExtensionMap.Add(".pko", "application/vndms-pkipko");
ExtensionMap.Add(".ppt", "application/vnd.ms-powerpoint");
ExtensionMap.Add(".pmr", "application/x-perfmon");
ExtensionMap.Add(".pma", "application/x-perfmon");
ExtensionMap.Add(".pot", "application/vnd.ms-powerpoint");
ExtensionMap.Add(".prf", "application/pics-rules");
ExtensionMap.Add(".pgm", "image/x-portable-graymap");
ExtensionMap.Add(".qt", "video/quicktime");
ExtensionMap.Add(".ra", "audio/x-pn-realaudio");
ExtensionMap.Add(".rgb", "image/x-rgb");
ExtensionMap.Add(".ram", "audio/x-pn-realaudio");
ExtensionMap.Add(".rmi", "audio/mid");
ExtensionMap.Add(".ras", "image/x-cmu-raster");
ExtensionMap.Add(".roff", "application/x-troff");
ExtensionMap.Add(".rtf", "application/rtf");
ExtensionMap.Add(".rtx", "text/richtext");
ExtensionMap.Add(".sv4crc", "application/x-sv4crc");
ExtensionMap.Add(".spc", "application/x-pkcs7-certificates");
ExtensionMap.Add(".setreg", "application/set-registration-initiation");
ExtensionMap.Add(".snd", "audio/basic");
ExtensionMap.Add(".stl", "application/vndms-pkistl");
ExtensionMap.Add(".setpay", "application/set-payment-initiation");
ExtensionMap.Add(".stm", "text/html");
ExtensionMap.Add(".shar", "application/x-shar");
ExtensionMap.Add(".sh", "application/x-sh");
ExtensionMap.Add(".sit", "application/x-stuffit");
ExtensionMap.Add(".spl", "application/futuresplash");
ExtensionMap.Add(".sct", "text/scriptlet");
ExtensionMap.Add(".scd", "application/x-msschedule");
ExtensionMap.Add(".sst", "application/vndms-pkicertstore");
ExtensionMap.Add(".src", "application/x-wais-source");
ExtensionMap.Add(".sv4cpio", "application/x-sv4cpio");
ExtensionMap.Add(".tex", "application/x-tex");
ExtensionMap.Add(".tgz", "application/x-compressed");
ExtensionMap.Add(".t", "application/x-troff");
ExtensionMap.Add(".tar", "application/x-tar");
ExtensionMap.Add(".tr", "application/x-troff");
ExtensionMap.Add(".tif", "image/tiff");
ExtensionMap.Add(".txt", "text/plain");
ExtensionMap.Add(".texinfo", "application/x-texinfo");
ExtensionMap.Add(".trm", "application/x-msterminal");
ExtensionMap.Add(".tiff", "image/tiff");
ExtensionMap.Add(".tcl", "application/x-tcl");
ExtensionMap.Add(".texi", "application/x-texinfo");
ExtensionMap.Add(".tsv", "text/tab-separated-values");
ExtensionMap.Add(".ustar", "application/x-ustar");
ExtensionMap.Add(".uls", "text/iuls");
ExtensionMap.Add(".vcf", "text/x-vcard");
ExtensionMap.Add(".wps", "application/vnd.ms-works");
ExtensionMap.Add(".wav", "audio/wav");
ExtensionMap.Add(".wrz", "x-world/x-vrml");
ExtensionMap.Add(".wri", "application/x-mswrite");
ExtensionMap.Add(".wks", "application/vnd.ms-works");
ExtensionMap.Add(".wmf", "application/x-msmetafile");
ExtensionMap.Add(".wcm", "application/vnd.ms-works");
ExtensionMap.Add(".wrl", "x-world/x-vrml");
ExtensionMap.Add(".wdb", "application/vnd.ms-works");
ExtensionMap.Add(".wsdl", "text/xml");
ExtensionMap.Add(".xml", "text/xml");
ExtensionMap.Add(".xlm", "application/vnd.ms-excel");
ExtensionMap.Add(".xaf", "x-world/x-vrml");
ExtensionMap.Add(".xla", "application/vnd.ms-excel");
ExtensionMap.Add(".xls", "application/vnd.ms-excel");
ExtensionMap.Add(".xof", "x-world/x-vrml");
ExtensionMap.Add(".xlt", "application/vnd.ms-excel");
ExtensionMap.Add(".xlc", "application/vnd.ms-excel");
ExtensionMap.Add(".xsl", "text/xml");
ExtensionMap.Add(".xbm", "image/x-xbitmap");
ExtensionMap.Add(".xlw", "application/vnd.ms-excel");
ExtensionMap.Add(".xpm", "image/x-xpixmap");
ExtensionMap.Add(".xwd", "image/x-xwindowdump");
ExtensionMap.Add(".xsd", "text/xml");
ExtensionMap.Add(".z", "application/x-compress");
ExtensionMap.Add(".zip", "application/x-zip-compressed");
ExtensionMap.Add(".*", "application/octet-stream");
}
public static string GetMimeMapping(string fileExtension)
{
if (ExtensionMap.ContainsKey(fileExtension))
return ExtensionMap[fileExtension];
else
return ExtensionMap[".*"];
}
}
Ho scritto un programma per recuperare e convertire il file mime.types di Apache in un C # Dictionary<string, string> digitato dall'estensione del file. È qui:
https://github.com/cymen/ApacheMimeTypesToDotNet
L'output effettivo è questo file:
https://github.com/cymen/ApacheMimeTypesToDotNet/blob/master/ApacheMimeTypescs< a>
Speriamo che anche qualcun altro lo trovi utile!
Nisus: saresti disposto a pubblicare l'intero codice sorgente per la tua utility da qualche parte? sarebbe davvero utile. grazie!
Non importa ....
Ho modificato il file di definizione di apache per contenere solo voci con estensioni definite, quindi ho esteso il codice per caricare i tipi / estensioni dal file di testo in fase di esecuzione. Forse non è elegante ma batte sicuramente creando / mantenendo 630 righe di codice sorgente per i tipi mime.
[nel costruttore per MimeTypeCollection invece di queste cose: this.Add (new mimeTypeInfo (" application / applixware ", new List (new [] {" .aw "})));]
// import mime/extension definition list to facilitate maintenance
string dir = AppDomain.CurrentDomain.BaseDirectory;
using (TextReader streamReader = new StreamReader(Path.Combine(dir, "MimeDefinitions.txt")))
{
string input;
while ((input = streamReader.ReadLine()) != null)
{
if (input.Substring(0, 1) != "#")
{
// text line format ::= [contenttype]<tab>[space delimited list of extensions, without dot]
string contentType = input.Group("0\t1");
string extensionList = input.Group("1\t1");
string[] extensions = extensionList.Split(" ".ToCharArray());
List<string> extensionSet = new List<string>();
foreach (string term in extensions)
{
extensionSet.Add("."+term);
}
this.Add(new mimeTypeInfo(contentType, extensionSet));
}
}
}
Ho anche scoperto che il metodo Init () sarebbe stato chiamato e che i membri _extensions e _mime non sarebbero stati completamente inizializzati, quindi l'ho cambiato in read:
if (_extensions == null || _mimes == null || _mimes.Count != this.Count)
Comunque, ora ho bisogno di una classe in grado di gestire i defs esterni e il registro locale.
Grazie!
Ho anche scoperto che il metodo Init () sarebbe stato chiamato e i membri _extensions e _mime non sarebbero stati completamente inizializzati, quindi l'ho cambiato in lettura, e il modo migliore è, rimuovere la chiamata GetExtension nel costruttore da MimeTypeCollection:
public MimeTypeCollection()
{
this.Add(new mimeTypeInfo("application/applixware", new List<string>(new[] { ".aw" })));
this.Add(new mimeTypeInfo("application/atom+xml", new List<string>(new[] { ".atom" })));
// ... Whole list from apache's site
this.Add(new mimeTypeInfo("x-x509-ca-cert", new List<string>(new[] { ".cer" })));
try
{
using (RegistryKey classesRoot = Registry.ClassesRoot)
using (RegistryKey typeKey = classesRoot.OpenSubKey(@"MIME\Database\Content Type"))
{
string[] subKeyNames = typeKey.GetSubKeyNames();
string extension = string.Empty;
foreach (string keyname in subKeyNames)
{
string trimmed = (keyname ?? string.Empty).Trim();
if (string.IsNullOrEmpty(trimmed))
continue;
if (this.Exists(mime => mime.MimeType == trimmed))
continue;
//if (!String.IsNullOrEmpty(GetExtension(trimmed)))
// continue;
string subKey = "MIME\\Database\\Content Type\\" + trimmed;
using (RegistryKey curKey = classesRoot.OpenSubKey(subKey))
{
extension = (curKey.GetValue("Extension") as string ?? string.Empty).Trim();
if (extension.Length > 0)
this.Add(new mimeTypeInfo(trimmed
, new List<string>(new[] { extension })));
}
}
}
}
catch (Exception ex)
{
string s = ex.ToString();
}
}
Vorrei solo metterti in guardia contro il recupero del tipo Mime / content di un file senza convalidarlo rispetto al contenuto effettivo del file, in quanto potrebbe comportare un serio rischio per la sicurezza del tuo sistema e degli utenti.
Sebbene esistano casi d'uso validi per qualcosa del genere, gli aggressori possono potenzialmente attaccare il tuo sistema o usarlo come meccanismo per propagare file dannosi ad altri utenti, mascherando eseguibili o script come altri tipi di file non sospetti.
Si consiglia di prendere seriamente in considerazione il sandboxing e di eseguire un'ispezione approfondita del contenuto sui file caricati prima di continuare a elaborarlo (o renderlo disponibile per il download).
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