Обсуждение: serialized objects and JDBC driver

I am attempting to serialize objects into Postgresql using the
JDBC driver. I am attempting to do this the standard way
using Object and Byte streams.

To store the object to the database in a text (blob) field I use the
following code to turn my object into a byte[].

             // create the serialized object and store in the database
             EncryptionInfo serObj = new EncryptionInfo(32, 32);
             ByteArrayOutputStream bos = new ByteArrayOutputStream();
             ObjectOutputStream p = new ObjectOutputStream(bos);
                 p.writeObject(serObj);
                 p.flush();
             byte[] data = bos.toByteArray();


This seems to go into the database with no errors.
However when I retieeve the data using the following code...

ByteArrayInputStream bis = new ByteArrayInputStream(data);
         ObjectInputStream p = new ObjectInputStream(bis);
         EncryptionInfo ei = (EncryptionInfo)p.readObject();

I get the following error...
InputStream does not contain a serialized object


Thanks.
Stuart Barlow.

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> ByteArrayInputStream bis = new ByteArrayInputStream(data);
>          ObjectInputStream p = new ObjectInputStream(bis);
>          EncryptionInfo ei = (EncryptionInfo)p.readObject();

Are you using setBytes/getBytes in JDBC?  That's worked for me when the SQL
type is OID on 7.1beta4.

David

It might be worth your while having a look at JSX as an alternative to standard
Java serialization. JSX serializes Java objects to XML which, being plain text,
may be easier to manage.
I haven't done any serious work with JSX yet but it seems to work well in the
trials I've done.

Check out http://www.csse.monash.edu.au/~bren/JSX/

Have Fun,
John L.

Quoting Stuart Barlow <sbarlow@peopledoc.com>:

>
> I am attempting to serialize objects into Postgresql using the
> JDBC driver. I am attempting to do this the standard way
> using Object and Byte streams.
>
> To store the object to the database in a text (blob) field I use the
> following code to turn my object into a byte[].
>
>              // create the serialized object and store in the database
>              EncryptionInfo serObj = new EncryptionInfo(32, 32);
>              ByteArrayOutputStream bos = new ByteArrayOutputStream();
>              ObjectOutputStream p = new ObjectOutputStream(bos);
>                  p.writeObject(serObj);
>                  p.flush();
>              byte[] data = bos.toByteArray();
>
>
> This seems to go into the database with no errors.
> However when I retieeve the data using the following code...
>
> ByteArrayInputStream bis = new ByteArrayInputStream(data);
>          ObjectInputStream p = new ObjectInputStream(bis);
>          EncryptionInfo ei = (EncryptionInfo)p.readObject();
>
> I get the following error...
> InputStream does not contain a serialized object
>
>
> Thanks.
> Stuart Barlow.
>
> *************************************************************************
> Information in this email is confidential and may be privileged. It is
> intended for the named addressee(s) only. If you have received it in
> error please notify the sender immediately and delete it from your
> system. You should not otherwise copy, retransmit, use or disclose its
> contents to anyone.
> *************************************************************************
>
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