Name: nt126004 Date: 02/27/2003


FULL PRODUCT VERSION :
java version "1.4.1_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_01-b01)
Java HotSpot(TM) Client VM (build 1.4.1_01-b01, mixed mode)

FULL OPERATING SYSTEM VERSION : Occurs on all OS versions


ADDITIONAL OPERATING SYSTEMS : All



A DESCRIPTION OF THE PROBLEM :
The constructor for the java.nio.charset.Charset class
takes a String for the canonical name and an array of
Strings as aliases. It check all of these using the
private checkName method, which throws an
IllegalCharsetNameException if the name contains anything
but 'A'-'Z', 'a'-'z', '0'-'9', '_', '-', ':', or '.'.
This is overly restrictive, particularly for aliases,
preventing the intended use of the name/alias combination
in certain situations. As an example, a common protocol
in medical imaging (DICOM), identifies 'ISO-8859-1'
as 'ISO_IR 100'. It would be nice to be able to alias
this DICOM name to 'ISO-8859-1', but it is not possible
given the current code constructs. Additionally, and just
as problematic, is the fact that aliases cannot be added
to the existing character sets.
As a suggested fix, I would recommend that the JDK allow
alias to be added to existing character set classes and
that, in all cases, aliases not be checked for strict
naming correctness (checking the canonical name seems fine
to me). Additionally, I would recommend that the
checkName method be scoped publicly so that the developer
could check the alias name's correctness themselves if
desired.

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER WORKAROUND :
The work-around is somewhat hackish and inelegant. It
requires the creation of a new CharsetProvider simply to
provide the aliasing for non-strict names. This work-
around is dependant upon the current use of the checkName
method - increased or modified use of this method
(specifically in the Charset.lookup method) may invalidate
the work-around in future versions.
(Review ID: 181774)
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