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RE: [INTERFACES] Large Object Exception/Serializing Java Objects

From: Peter Mount <petermount(at)it(dot)maidstone(dot)gov(dot)uk>
To: "'Joe Shevland'" <shevlandj(at)kpi(dot)com(dot)au>, Peter Mount <petermount(at)it(dot)maidstone(dot)gov(dot)uk>, pgsql-interfaces(at)postgresql(dot)org
Subject: RE: [INTERFACES] Large Object Exception/Serializing Java Objects
Date: 1999-12-10 11:56:58
Message-ID: 1B3D5E532D18D311861A00600865478C70BF72@exchange1.nt.maidstone.gov.uk (view raw or flat)
Thread:
Lists: pgsql-interfaces

-----Original Message-----
From: Joe Shevland [mailto:shevlandj(at)kpi(dot)com(dot)au]
Sent: Saturday, December 11, 1999 6:48 AM
To: Peter Mount; pgsql-interfaces(at)postgreSQL(dot)org
Subject: Re: [INTERFACES] Large Object Exception/Serializing Java
Objects


I'm pretty sure I compiled it to a 1.2 version (==JDBC2.0?) although
with
the requirements of gnujsp/jserv/apache I may have tied myself in a
knot.

PM: Infact, the LO & Serializing code is identical in both versions, so
it shouldn't really matter in these cases (both are subpackages).

Failing that, I'm using a 1.3 vm on Windows 98 to communicate with a
1.1.8
FreeBSD JVM. That could be the prob?? (actually, having said it, it
sounds
like that could well be the problem)  Its all to try and faciliate
persistance of Java objects with EJBoss (www.ejboss.org); if there's
easier
options I'm happy. This is probably an effort everyone in the open
source
comunity will benefit from too when you realize the benefits of EJB's...

PM: I'll have to take a look at it. It's possible as 1.3 may have a
different Serialising format than 1.1.8 (the Swing docs actually state
that it would be incompatible).

Thanks heaps for input,

(BTW, the 'Z' error sounds ominous :)

(And also BTW, I love the way people overseas are awake when I'm busily
coding at night... Australians coders must be a dying breed :)

PM: It's a common knowledge that the best software code is produced at
3am - I know that mine does - too many distractions otherwise.

Cheers,
Joe


----- Original Message -----
From: "Peter Mount" <petermount(at)it(dot)maidstone(dot)gov(dot)uk>
To: "'Joe Shevland'" <shevlandj(at)kpi(dot)com(dot)au>;
<pgsql-interfaces(at)postgreSQL(dot)org>
Sent: Thursday, December 09, 1999 11:38 PM
Subject: RE: [INTERFACES] Large Object Exception/Serializing Java
Objects


> Joe, what version of the driver are you using?
>
> The Z error I thought was fixed some time ago. Originally the fastpath
> code was based on libpq, but I found that the backend also send a
packet
> labeled Z, so added a check for it.
>
> Peter
>
> --
> Peter Mount
> Enterprise Support
> Maidstone Borough Council
> Any views stated are my own, and not those of Maidstone Borough
Council.
>
>
>
> -----Original Message-----
> From: Joe Shevland [mailto:shevlandj(at)kpi(dot)com(dot)au]
> Sent: Friday, December 10, 1999 7:35 PM
> To: pgsql-interfaces(at)postgreSQL(dot)org
> Subject: [INTERFACES] Large Object Exception/Serializing Java Objects
>
>
> Hi all,
>
> I'm trying to persist some Java objects in a PostgreSQL database using
> JDBC
> (2.0).
>
> I get the following error:
>
> Fri Dec 10 11:26:15 PST 1999 - [copyright] EJBoss - The EJB Open
Source
> Server v0.9
> Fri Dec 10 11:26:48 PST 1999 - [Exception]
> Fri Dec 10 11:26:48 PST 1999 - FastPath protocol error: Z
> FastPath protocol error: Z
>  at postgresql.fastpath.Fastpath.fastpath(Fastpath.java:159)
>  at postgresql.fastpath.Fastpath.fastpath(Fastpath.java:188)
>  at postgresql.fastpath.Fastpath.getInteger(Fastpath.java:200)
>  at
>
postgresql.largeobject.LargeObjectManager.create(LargeObjectManager.java
> :176
> )
>  at
>
org.ejboss.storage.PGSecondaryStorage.serialize(PGSecondaryStorage.java:
> 245)
>  at
>
org.ejboss.storage.PGSecondaryStorage.store(PGSecondaryStorage.java:117)
>  at
>
org.ejboss.ejb.EnterpriseBeanWrapper.passivate(EnterpriseBeanWrapper.jav
> a:34
> 3)
>  at
>
org.ejboss.managers.EnterpriseBeanWrapperManager$LRUThread.run(Enterpris
> eBea
> nWrapperManager.java:403)
>  at java.lang.Thread.run(Thread.java:479)
>
> This occurs upon trying to create the large object... before going to
> the
> source I just wanted to check that this is supposed to work and all
> that.
>
> Out of interest, here's the offending code fragment (it may be just
> plain
> wrong... any ideas appreciated!):
>
>     private int serialize(EnterpriseBean bean)
>         throws IOException, SQLException
>     {
>         ByteArrayOutputStream   byte_out = new
ByteArrayOutputStream();
>         ByteArrayInputStream    byte_in;
>         ObjectOutputStream      obj_out = new
> ObjectOutputStream(byte_out);
>
>         byte[]                  classbytes;
>         byte                    buf[] = new byte[2048];
>         int                     read=0;
>
>         // lobj was created in the constructor...
>
>         // Create the ejb object using the PostgreSQL specific blob
> support
>         int oid =
> lobj.create(LargeObjectManager.READ|LargeObjectManager.WRITE);
>
>         LargeObject obj = lobj.open(oid,LargeObjectManager.WRITE);
>         DriverManager.println("[PGSecondaryStorage] Got large object
> obj="+obj);
>
>         // Copy the EJB to a temporary byte array
>         obj_out.writeObject( bean );
>         obj_out.flush();
>         classbytes = byte_out.toByteArray();
>         byte_in = new ByteArrayInputStream(classbytes);
>
>         // Copy the data to the large object
>         while((read=byte_in.read(buf,0,2048))>0) {
>           obj.write(buf,0,read);
>         }
>
>         obj.close();
>
>         return oid;
>     }
>
>
> Thanks,
> Joe.
>
>
> ---
> Joe Shevland
> Principal Consultant
> KPI Logistics Pty Ltd
> mailto:shevlandj(at)kpi(dot)com(dot)au
> http://www.kpi.com.au
>
>
> ************
>

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Subject: Re: [INTERFACES] Apache+PostgreSQL+PHP3
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Subject: RE: [INTERFACES] Large Object Exception/Serializing Java Objects

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