File file = new File( pfileName);
request.setCharacterEncoding("UTF-8");

//*****이부분 추가 해줘야함 *****
response.setHeader("Accept-Ranges", "bytes"); 
//***** 이부분 추가 해줘야함 *****

response.setContentType("application/download; utf-8");
response.setContentLength((int)file.length());

참조

[SoundHub] HTTP Range Requests – Che1's Blog