title: How to determine appropriate file extension from MIME Type in Java
body: <p>I am uploading files to an Amazon s3 bucket and have access to the InputStream and a String containing the MIME Type of the file but not the original file name.  It's up to me to actually create the file name and extension before pushing the file up to S3.  Is there a library or convenient way to determine the appropriate extension to use from the MIME Type?  </p>
  
  <p>I've seen some references to the Apache Tika library but that seems like overkill and I haven't been able to get it to successfully detect file extensions yet.  From what I've been able to gather it seems like this code should work, but I'm just getting an empty string when my type variable is "image/jpeg"</p>
  
  <pre><code>    MimeType mimeType = null;
      try {
          mimeType = new MimeTypes().forName(type);
      } catch (MimeTypeException e) {
          Logger.error("Couldn't Detect Mime Type for type: " + type, e);
      }
  
      if (mimeType != null) {
          String extension = mimeType.getExtension();
          //do something with the extension
      }
  </code></pre>