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Posted to ojb-user@db.apache.org by Björn Voigt <bv...@hs-harz.de> on 2003/09/17 18:38:30 UTC
Problem with byte[] to bytea mapping
Hi Obj_friends,
I have problems with mapping of an image to an postgresql database.
A byte[] attribute holds my image data. The column type is bytea.
The mapping look like:
<class-descriptor class="de.mobiharz.model.media.Image" table="images">
...
<field-descriptor
id="3"
name="image_data"
column="imag_data"
jdbc-type="BINARY"/>
...
</class-descriptor>
If I store the object to database and get it back, the length of
the byte[] is bigger than the original length.
It would be nice , if somebody can help
Björn
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Re: Problem with byte[] to bytea mapping
Posted by Armin Waibel <ar...@code-au-lait.de>.
Hi,
in a previous mail you said
> Castor allows u to map an byte[] to BLOB (bytea in postgres).
in OJB if the standard mapping does not fulfill your
expectations it is possible to use OJB's FieldConversion
feature.
See http://db.apache.org/ojb/repository.html#field-descriptor
OJB was shipped with some standard FieldConversion classes.
Maybe this will help you.
regards,
Armin
----- Original Message -----
From: "Björn Voigt" <bv...@hs-harz.de>
To: <oj...@db.apache.org>
Sent: Thursday, September 18, 2003 12:01 PM
Subject: Re: Problem with byte[] to bytea mapping
> Christian Pesch schrieb:
> > Björn Voigt wrote:
> >
> >> If I store the object to database and get it back, the length of
> >> the byte[] is bigger than the original length.
> >
> >
> > Did you compare the original value and the written one?
> > May be that gives a hint.
>
> In my last message I wrote some wrong,
>
> I tested the storing again with castor and ojb.
>
> I made 4 tests.
>
> 1. Store with Castor / Load with Castor successful
> 2. Store with Ojb / Load with Ojb non successful
> 3. Store with Castor / Load with Ojb non successful
> 4. Store with Ojb / Load with Castor non successful
>
> select length(image_column) from images has in all cases
> the same value. The data of all 4 rows looks same.
>
>
>
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>
>
>
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Re: Problem with byte[] to bytea mapping
Posted by Björn Voigt <bv...@hs-harz.de>.
Christian Pesch schrieb:
> Björn Voigt wrote:
>
>> If I store the object to database and get it back, the length of
>> the byte[] is bigger than the original length.
>
>
> Did you compare the original value and the written one?
> May be that gives a hint.
In my last message I wrote some wrong,
I tested the storing again with castor and ojb.
I made 4 tests.
1. Store with Castor / Load with Castor successful
2. Store with Ojb / Load with Ojb non successful
3. Store with Castor / Load with Ojb non successful
4. Store with Ojb / Load with Castor non successful
select length(image_column) from images has in all cases
the same value. The data of all 4 rows looks same.
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Re: Problem with byte[] to bytea mapping
Posted by Björn Voigt <bv...@hs-harz.de>.
Christian Pesch schrieb:
> Björn Voigt wrote:
>
>> If I store the object to database and get it back, the length of
>> the byte[] is bigger than the original length.
>
>
> Did you compare the original value and the written one?
> May be that gives a hint.
Hi Christian,
here are the sample files I use,
test1.jpg was written to db using ojb
test2.jpg ist the result.
The length of the image is bigger then the original length,
there goes something wrong during the insert. I used castor
before with the same class and table, but there goes nothing
wrong.
Castor allows u to map an byte[] to BLOB (bytea in postgres).
I tried BINARY/VARBINARY/LONGVARBINARY in ojb, but I got this
wrong byte[] back.
Re: Problem with byte[] to bytea mapping
Posted by Christian Pesch <ch...@coremedia.com>.
Björn Voigt wrote:
> If I store the object to database and get it back, the length of
> the byte[] is bigger than the original length.
Did you compare the original value and the written one?
May be that gives a hint.
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