At 10:12 PM 3/4/01 +0530, J.Ganesan wrote:
>
>
>Paul Brinkley wrote:
>
>> At 12:05 PM 3/3/01 +0530, J.Ganesan wrote:
>> >Hi all,
>> > I have a class X , which extends AbstractTableModel. When I save an
>> >object of X, the JTable whose TableModel is the object of X, is also
>> >serialized and saved. I am interseted ONLY in the private data of X.
>> >Besides, the file size becomes unacceptably big.
>> > Any suggestions to solve this problem ?
>> > Thanks.
>>
>> If you're only interested in an X's private data, you should
>> probably extract it explicitly and save it, rather than
>> trying to serialize the X object itself. The reason for
>> this is that some other class may need to save the state
>> of the entire X object, including any JTables it references.
>
>How can we do this ? Because, even if we implement writeObject() method
>for the private data , the defaultWriteObject() method operates on super
>class .
>With the result that JTable is also serialized.
That's correct. (With the proviso that I still don't know
how this table model is referencing JTable non-transiently.
It was my understanding that event listeners were transient.
Can anyone give a better explanation? Is it because
AbstractTableModel doesn't extent Component? Is there a
John Zukowski in the house? :-) )
The standard way around this is externalization. It's a
more hands-on version of serialization. First, have your
class implement java.io.Externalizable. Then you have to
implement two methods it defines; I can't remember the
names of them off the top of my head, but they're clearly
outlined in the Javadoc for Externalizable. An externalizable
object writes -only- those fields you tell it to in the
"write" method.
The superclass is initialized using its no-arg constructor.
AbstractTableModel happens to have one, so you're fine there.
Again, I'm not certain serialization/externalization is the
"right" approach here, since you're explicitly interested
in saving only the table data. I would implement a method
on X that saves just table data, but that's me.
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