FULL PRODUCT VERSION :
java version "1.8.0_161"
Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
Java HotSpot(TM) Client VM (build 25.161-b12, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Sürüm 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
While using BasicAuthenticator, turkish characters are correctly handled.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
include turkish character as user and/or password like "şŞİıöÖğĞüÜçÇ"

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
user and password provided should correctly authanticate.
ACTUAL -
the string is converted as they are single byte encoded characters.

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
created local version of class BasicAıthenticator.java

in class BasicAuthenticatior line 76, changed the line
from
       String userpass = new String (b);

to
       String userandpass = UTF8String.getValue(b);