假设我有一个完整的文件路径:(/sdcard/tlogo.png)。我想知道它的mime类型。

我为它创建了一个函数

public static String getMimeType(File file, Context context)    
{
    Uri uri = Uri.fromFile(file);
    ContentResolver cR = context.getContentResolver();
    MimeTypeMap mime = MimeTypeMap.getSingleton();
    String type = mime.getExtensionFromMimeType(cR.getType(uri));
    return type;
}

但当我调用它时,它返回null。

File file = new File(filePath);
String fileType=CommonFunctions.getMimeType(file, context);

当前回答

上面的解决方案在.rar文件的情况下返回null,使用URLConnection.guessContentTypeFromName(url)在这种情况下工作。

其他回答

get file object....
File file = new File(filePath);

then....pass as a parameter to...

getMimeType(file);

...here is 


public String getMimeType(File file) {
        String mimetype = MimeTypeMap.getSingleton().getMimeTypeFromExtension(MimeTypeMap.getFileExtensionFromUrl(Uri.fromFile(file).toString()).toLowerCase());
        if (mimetype == null) {
            return "*/*";
        }
        return mimetype;///return the mimeType
    }
// This will return the mimeType. 
// for eg. xyz.png it will return image/png. 
// here uri is the file that we were picked using intent from ext/internal storage.
private String getMimeType(Uri uri) {
   // This class provides applications access to the content model.  
   ContentResolver contentResolver = getContentResolver();

   // getType(Uri url)-Return the MIME type of the given content URL. 
   return contentResolver.getType(uri);
}

Mime从本地文件:

String url = file.getAbsolutePath();
FileNameMap fileNameMap = URLConnection.getFileNameMap();
String mime = fileNameMap.getContentTypeFor("file://"+url);

我也遇到过类似的问题。到目前为止,我知道不同的名字可能会有不同的结果,所以最终得出了这个解决方案。

public String getMimeType(String filePath) {
    String type = null;
    String extension = null;
    int i = filePath.lastIndexOf('.');
    if (i > 0)
        extension = filePath.substring(i+1);
    if (extension != null)
        type = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
    return type;
}  

首先,你应该考虑调用MimeTypeMap#getMimeTypeFromExtension(),就像这样:

// url = file path or whatever suitable URL you want.
public static String getMimeType(String url) {
    String type = null;
    String extension = MimeTypeMap.getFileExtensionFromUrl(url);
    if (extension != null) {
        type = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
    }
    return type;
}