8000685: (props) Properties.storeToXML/loadFromXML should only require UTF-8 and UTF-16 to be supported
Alan.Bateman at oracle.com
Fri Oct 12 10:19:29 UTC 2012
A few days ago we added a JDK private provider interface  to which
the Properties loadFromXML and storeToXML methods will delegate. The
motive as I mentioned is to allow for a smaller environments where JAXP
might not be present (so motivated by both modules and the compact
The next step in this effort is dealing with the issue of arbitrary
encodings. The storeToXML method allows the encoding to be specified,
the loadFromXML method assumes that the implementation can decode the
stream and read the encoding declaration. The specification doesn't make
it clear how either method behaves with unrecognized encodings and this
is something that we need to fix in order to allow for alternative
implementations, in particular tiny parsers that might not support more
than a few.
The webrev the proposed changes is here:
The proposal is that an implementation minimally supports UTF-8 and
UTF-16, which I think is consistent with the W3C XML specification .
Based on a search of a large number of projects then it appears that
these methods aren't used very much so I don't think this will have any
significant impact. In addition the same set of encodings [ which is not
exactly the same set as Charsets.availableCharsets().keySet() ] that
works today will continue to work when the service provider that uses
JAXP is installed.
In addition, to specifying the required encodings, I have also changed
both methods to specify that UnsupportedEncodingException may be thrown.
In the case of loadFromXML then this is the long standing behavior
anyway. In the case of storeToXML then the long standing behavior is
somewhat bizarre. If the method is invoked with an unsupported encoding
then the underlying Xalan code prints a warning to System.out and
changes the encoding under the covers to UTF-8. I've submitted a bug on
this oddity; in the mean-time I've added a check in the platform
provider to always fail for charsets that aren't recognized.
More information about the core-libs-dev