code: public static String getContentType(final String fileName) {
  
  		if (Util.empty(fileName)) {
  			return ConfigurationProperties.getDefaultMimeType();
  		}
  
  		String mimeType = null;
  
  		if (fileName.lastIndexOf('.') > -1) {
  			String suffix = fileName.substring(fileName.lastIndexOf('.') + 1).toLowerCase();
  			mimeType = ConfigurationProperties.getFileMimeTypeForExtension(suffix);
  		}
  
  		if (mimeType == null) {
  			mimeType = URLConnection.guessContentTypeFromName(fileName);
  			if (mimeType == null) {
  				mimeType = ConfigurationProperties.getDefaultMimeType();
  			}
  		}
  
  		return mimeType;
  	}
docs: Attempts to guess the content-type for the given file name.
  
  @param fileName the file name to return the content-type for.
  @return the content-type for the given fileName, or a generic type if unknown.