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DefaultTableModel.getDataVector() and Java 11

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  DefaultTableModel.getDataVector() and Java 11 Andreas Leitgeb <avl@logic.at> - 2019-04-03 15:53 +0000
    Re: DefaultTableModel.getDataVector() and Java 11 Patrick Roemer <sangamon@netcologne.de> - 2019-04-03 18:37 +0200
      Re: DefaultTableModel.getDataVector() and Java 11 Andreas Leitgeb <avl@logic.at> - 2019-04-03 16:41 +0000
    Re: DefaultTableModel.getDataVector() and Java 11 Eric Sosman <esosman@comcast-dot-net.invalid> - 2019-04-03 12:44 -0400
      Re: DefaultTableModel.getDataVector() and Java 11 Andreas Leitgeb <avl@logic.at> - 2019-04-03 17:33 +0000
        Re: DefaultTableModel.getDataVector() and Java 11 Eric Douglas <e.d.programmer@gmail.com> - 2019-04-03 11:22 -0700
    Re: DefaultTableModel.getDataVector() and Java 11 Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2019-04-03 18:49 +0200
    Re: DefaultTableModel.getDataVector() and Java 11 Eric Douglas <e.d.programmer@gmail.com> - 2019-04-03 10:34 -0700

#38847 — DefaultTableModel.getDataVector() and Java 11

In Java up to 8  DefaultTableModel had a method  getDataVector()
that returned a raw Vector.

My application's custom TableModel overrode the method to return
a Vector<MyRowType>, where MyRowType provided direct type-safe
accessors for each column.

In Java 11 it seems to have changed to returning a Vector of 
raw Vectors.

At first glance this seems just goofy to me, because that doesn't
really make it type-safe (it still involves a raw type), and it even
prevents me from making it type-safe myself.

I hope, someone here can provide me with a second glance that
clarifies the rationale behind the change.

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#38848

Responding to Andreas Leitgeb:
> In Java up to 8  DefaultTableModel had a method  getDataVector()
> that returned a raw Vector.
> 
> My application's custom TableModel overrode the method to return
> a Vector<MyRowType>, where MyRowType provided direct type-safe
> accessors for each column.
> 
> In Java 11 it seems to have changed to returning a Vector of 
> raw Vectors.
> 
> At first glance this seems just goofy to me, because that doesn't
> really make it type-safe (it still involves a raw type), and it even
> prevents me from making it type-safe myself.
> 
> I hope, someone here can provide me with a second glance that
> clarifies the rationale behind the change.

API doc for this method in Java 8: "Returns the Vector of Vectors that
contains the table's data values." There's quite a few occurrences of
casts such as "(Vector)dataVector.elementAt(row)" in the
DefaultTableModel code, too.

So it seems that using another element type than Vector with
DefaultTableModel has never really been a safe option, and the change
only codifies to types what the contract has always been saying. Custom
[Abstract]TableModel to the rescue...

Best regards,
Patrick

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#38849

Patrick Roemer <sangamon@netcologne.de> wrote:
> Responding to Andreas Leitgeb:
>> In Java up to 8  DefaultTableModel had a method  getDataVector()
>> that returned a raw Vector.
>> 
>> My application's custom TableModel overrode the method to return
>> a Vector<MyRowType>, where MyRowType provided direct type-safe
>> accessors for each column.
>> 
>> In Java 11 it seems to have changed to returning a Vector of 
>> raw Vectors.
>> 
>> At first glance this seems just goofy to me, because that doesn't
>> really make it type-safe (it still involves a raw type), and it even
>> prevents me from making it type-safe myself.
>> 
>> I hope, someone here can provide me with a second glance that
>> clarifies the rationale behind the change.
>
> API doc for this method in Java 8: "Returns the Vector of Vectors that
> contains the table's data values." There's quite a few occurrences of
> casts such as "(Vector)dataVector.elementAt(row)" in the
> DefaultTableModel code, too.
>
> So it seems that using another element type than Vector with
> DefaultTableModel has never really been a safe option, and the change
> only codifies to types what the contract has always been saying. Custom
> [Abstract]TableModel to the rescue...

Thanks a lot - it now makes sense with that background.

Will see what I really need beyond AbstractTableModel.

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#38850

On 4/3/2019 11:53 AM, Andreas Leitgeb wrote:
> In Java up to 8  DefaultTableModel had a method  getDataVector()
> that returned a raw Vector.
> 
> My application's custom TableModel overrode the method to return
> a Vector<MyRowType>, where MyRowType provided direct type-safe
> accessors for each column.
> 
> In Java 11 it seems to have changed to returning a Vector of
> raw Vectors.
> 
> At first glance this seems just goofy to me, because that doesn't
> really make it type-safe (it still involves a raw type), and it even
> prevents me from making it type-safe myself.
> 
> I hope, someone here can provide me with a second glance that
> clarifies the rationale behind the change.

     Just an untested thought: Could MyRowType extend Vector,
or even Vector<T>?

-- 
esosman@comcast-dot-net.invalid
Six hundred fifty-eight days to go.

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#38853

Eric Sosman <esosman@comcast-dot-net.invalid> wrote:
> On 4/3/2019 11:53 AM, Andreas Leitgeb wrote:
>> I hope, someone here can provide me with a second glance that
>> clarifies the rationale behind the change.
>      Just an untested thought: Could MyRowType extend Vector,
> or even Vector<T>?

"Vector<Vector>" isn't the same as "Vector<? extends Vector>"

(despite the theory, I tried anyway, and got the expected 
error that Vector<TestVectorSubclass> is indeed not convertible
to Vector<Vector>)


Patrick's advice to use AbstractTableModel already solved that
one for me.

PS:
Some comment for private method "justifyRows" of DefaultTableModel
that I noticed only in the course of changing to AbstractTableModel
reveals developers' intention:
"       // Sometimes the DefaultTableModel is subclassed
"       // instead of the AbstractTableModel by mistake.
Yep, I was guilty of that - fixed now in my code.

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#38855

On Wednesday, April 3, 2019 at 1:33:38 PM UTC-4, Andreas Leitgeb wrote:
> PS:
> Some comment for private method "justifyRows" of DefaultTableModel
> that I noticed only in the course of changing to AbstractTableModel
> reveals developers' intention:
> "       // Sometimes the DefaultTableModel is subclassed
> "       // instead of the AbstractTableModel by mistake.
> Yep, I was guilty of that - fixed now in my code.

I may have just found that note myself at some point, that the DefaultTableModel is not intended to be overridden.  I knew there was a reason I ended up extending the AbstractTableModel, while I know I initially tried to extend the default which seemed like it should be less work.

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#38851

On 2019-04-03 17:53, Andreas Leitgeb wrote:
> In Java up to 8  DefaultTableModel had a method  getDataVector()
> that returned a raw Vector.
> 
> My application's custom TableModel overrode the method to return
> a Vector<MyRowType>, where MyRowType provided direct type-safe
> accessors for each column.
> 
> In Java 11 it seems to have changed to returning a Vector of 
> raw Vectors.
> 
> At first glance this seems just goofy to me, because that doesn't
> really make it type-safe (it still involves a raw type), and it even
> prevents me from making it type-safe myself.
> 
> I hope, someone here can provide me with a second glance that
> clarifies the rationale behind the change.
> 

Well, /unless/, indeed, your intent is to override, it strikes me that:

Object cell = tableModel.getDataVector().get(0).get(0)

is more user-friendly than

Object cell = ((Vector<?>) tableModel.getDataVector().get(0)).get(0)

-- 
DF.

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#38854

On Wednesday, April 3, 2019 at 11:53:51 AM UTC-4, Andreas Leitgeb wrote:
> In Java up to 8  DefaultTableModel had a method  getDataVector()
> that returned a raw Vector.
> 
> My application's custom TableModel overrode the method to return
> a Vector<MyRowType>, where MyRowType provided direct type-safe
> accessors for each column.
> 
> In Java 11 it seems to have changed to returning a Vector of 
> raw Vectors.
> 
> At first glance this seems just goofy to me, because that doesn't
> really make it type-safe (it still involves a raw type), and it even
> prevents me from making it type-safe myself.
> 
> I hope, someone here can provide me with a second glance that
> clarifies the rationale behind the change.

It would seem I never found DefaultTableModel all that useful.  I have a class which contains the values needed to display one cell which just implements Comparable and Serializable.  Then I have a table model class which extends AbstractTableModel with an ArrayList variable.  Each element of the ArrayList contains a custom class which represents one row, constructed from a hard array [] of custom cell objects, implementing Comparable.  The custom table model class has a getRow method which returns a row class instance.  The custom row class has a getRowData method returning the entire array of cell data as well as a getColumnData method to return a single cell.

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