Tika currently misuses the HTTP Content-Encoding header, and does not seem to use the charset part of the Content-Type header properly.
Content-Encoding is not for the charset. It is for values like gzip, deflate, compress, or identity.
Charset is passed in with the Content-Type. For instance: text/html; charset=iso-8859-1
Tika should, in my opinion, do the following:
1. Stop using Content-Encoding, unless it wants me to be able to pass in gzipped content in an input stream.
2. Parse and understand charset=... declarations if passed in the Metadata object
3. Return charset=... declarations in the Metadata object if a charset is detected.