Hi Adrian,
I think you correctly identified the problem (encoding date via a
'toString()' method is definitely wrong), and looks like the patch
attached to CAY-792 should fix it by not including any textual output
in the encoded date. There's one problem though - our existing users
may have stored XML that was encoded using the previous default
formatter. I guess I am going to add some failover strategy that
would try a previous formatter in case of parse exceptions..
On a side note - maybe we can improve encoder/decoder performance by
introducing some "context" object that internally stores reusable
thread-unsafe objects like formatters, instead of creating them for
every field?
Thanks
Andrus
On May 22, 2007, at 8:58 PM, Adrian Wiesmann wrote:
Hello
I guess I found a problem within the XML Serialisation/Deserialisation
code when working with Dates. But before posting a patch or bug in
JIRA I
thought I'd make sure that I really found a problem and am not hunting
ghosts (the wrong ones :) ).
The scenario is the following:
Serialising a list of objects with the XMLEncoder:
xmlEncoder.encode(myId, dataObjectList);
results in the date fields to be formatted like this:
"Tue Mar 13 20:56:11 CET 2007"
which basically represents this format:
"EEE MMM dd HH:mm:ss zzz yyyy"
That works like a charm. The resulting XML is well formatted.
The problem is then, when you try to read back such a deserialised
list
with the help of the XMLDecoder into a DataContext:
XMLDecoder.decodeList(buffer, dataContext);
Sometimes this resulted in our application in the following error:
Unparseable date: "Tue Mar 13 20:56:11 CET 2007"
and first we thought this is an error with Windows because the
error only
happened on that system. But after doing some testing I think we have
a locale problem:
The XMLDecoder decodes Dates like this:
formatter = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy");
formatter.parse("Tue Mar 13 20:56:11 CET 2007");
The problem is, that the SimpleDateFormat seems to use the locale
of the
respective system, although we define the mask it should use in its
constructor! I tried to use non lenient functionality:
formatter.setLenient(false);
but that didn't work as well. Which basically means the XMLDecoder and
XMLEncoder are not supporting different locales.
Can somebody confirm this behaviour? (And if yes, shouldn't we
change the
format of the date/time as well as the formatting within the
Decoder and
Encoder?)
Regards,
Adrian
P.S: This is some snippet to test the problem:
String strDate = "Tue Mar 13 20:56:11 CET 2007";
String strFormat = "EEE MMM dd HH:mm:ss zzz yyyy";
DateFormat formatter = new SimpleDateFormat(strFormat, Locale.CHINA);
try {
System.out.println(formatter.parse(strDate));
} catch (ParseException e) {
e.printStackTrace();
}
formatter = new SimpleDateFormat(strFormat, Locale.CHINA);
formatter.setLenient(false);
try {
System.out.println(formatter.parse(strDate));
} catch (ParseException e) {
e.printStackTrace();
}
formatter = new SimpleDateFormat(strFormat, Locale.US);
try {
System.out.println(formatter.parse(strDate));
} catch (ParseException e) {
e.printStackTrace();
}
