RFR: 6244047: impossible to specify directories to logging FileHandler unless they exist

[Jim Gish]

Please review 
http://cr.openjdk.java.net/~jgish/Bug6244047-FileHandler-CheckLockLocation/ 
<http://cr.openjdk.java.net/%7Ejgish/Bug6244047-FileHandler-CheckLockLocation/>

This updates the logging FileHandler to actually check the directory 
passed to it via the pattern to ensure that it exists and is writable.  
It does this before going into the loop to create lock files there which 
will fail repeatedly if the directory specified is invalid.  If the file 
specified does not exist, or is not a directory or not writable, an 
IOException with a precise message is thrown.

Note that this fix does not do as some users would like, which is to go 
ahead and create directories that don't exist.

Thanks,
    Jim

-- 
Jim Gish | Consulting Member of Technical Staff | +1.781.442.0304
Oracle Java Platform Group | Core Libraries Team
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Burlington, MA 01803
jim.gish at oracle.com