Issue2387

In 2.5x could have  jtablemodel contain datetime.date data and maintained column renderer for those datetime.date columns.
In 2.5x Table display would "auto-magically" convert the datetime.date to a corresponding java.sql.Date.
However in 2.7, the java.sql.Date value is one day less than the original datetime.date. 
I can rework the software to resolve this, but is this a bug in the new release for JTables?

Let's try this out:

>>> import datetime, java
>>> datetime.date.today()
datetime.date(2015, 9, 1)
>>> datetime.date.today().__tojava__(java.sql.Date)
2015-08-31

So there's the reported problem. Let's dig in further. Per above, Jython does this automatic conversion via __tojava__ methods on datetime.{date, datetime, time} Python classes. Here's the relevant conversion for datetime.date:

https://github.com/jythontools/jython/blob/master/Lib/datetime.py#L1073

    if _is_jython:
        def __tojava__(self, java_class):
            if java_class not in (Calendar, Date, Object):
                return Py.NoConversion
            calendar = _make_java_utc_calendar()
            calendar.set(self.year, self.month - 1, self.day)
            if java_class == Calendar:
                return calendar
            else:
                return Date(calendar.getTimeInMillis())

This code is problematic: java.sql.Date is in UTC; but datetime.date is naive.

>>> cal = datetime._make_java_utc_calendar()
>>> cal.clear()
>>> cal.set(2015, 8, 1)
>>> cal.getTimeInMillis()/1000.
1441065600.0
>>> time.time()
1441125551.691
>>> cal.getTimeInMillis()/1000. - time.time()
-59969.53800010681

Or a delta about 16.7 hours. More than enough to cause this issue.

I'm not certain what to do here. java.sql.Date models time differently than datetime.date. Providing this conversion might be worse than useless, but it's also something we have historically done so we cannot just remove.

Interestingly, datetime.datetime does not support conversion to java.sql.Date, which can be done correctly:

>>> datetime.datetime.now().__tojava__(java.sql.Date)
Error

So this specific conversion should be supported.

work around --
   if you use a python TableModel class holds datetime.date elements
   you need to create a python JTable class that is derived from a 
   java JTable class in which can override getValueAt and setValueAt.
   for each method you need to do the necessary "coversion":
      METHOD                    FROM                        TO
     getValueAt      datetime.date/java.util.Date       java.sql.Date
     setValueAt      java.sql.Date/java.util.Date       datetime.date

Thanks for addressing issue.

I have been careful about "casting" in general.
Unfortunately the implicit casting in JTable caught me off-guard.

Closing, unless there's something else we can do?