kohsuke/javax.activation — pull request #1 by ahmedmohiduet (2014-12-09 07:26:39+00:00)
Title: Update video audio types mp3,mkv,mp4,webm

Getting results :
application/octet-stream
application/octet-stream
application/octet-stream
application/octet-stream

for all of my codes:
System.out.println(MimetypesFileTypeMap.getDefaultFileTypeMap().getContentType("/usr/lo.cal/myfile.mp3"));
System.out.println(MimetypesFileTypeMap.getDefaultFileTypeMap().getContentType("/usr/lo.cal/myfile.mkv"));
System.out.println(MimetypesFileTypeMap.getDefaultFileTypeMap().getContentType("/usr/lo.cal/myfile.mp4"));
System.out.println(MimetypesFileTypeMap.getDefaultFileTypeMap().getContentType("/usr/lo.cal/myfile.webm"));