o.a.h.io.UTF8 is deprecated but is still used in multiple places. FSEditLog.java has 40 UTF8 related warnings. I don't think it is feasible to avoid using UTF8 in FSEditLog.java.
Two options to get rid of these warnings :
1. use @SupressWarnings at each use of UTF or for enclosing class.
2. define a wrapper class DeprecatedUTF8 that is not @deprecated.
I prefer the second option in this case since it keeps FSEditLog.java and other places clean and still makes it explicit that a deprecated class is used.
This is part of spring cleaning effort to remove warnings in javac. I will attach a patch for the second option.