RE: [Barcode4j-users] Using FOP extension from a web app

[Aaron T. <ata...@zi...>]

I wanted to let the list know that we were finally able to get the =
barcode extension working, but we may not be able to use it.

Our situation was that we could generate barcodes within FOP if invoked =
from the console and we could generate barcodes as images within the =
appserver, but using FOP within the appserver gave us no barcodes and no =
errors.

The problem seems to be some kind of mismatch between the fop.jar, =
batik.jar, and barcode4j.jar.  Unfortunately you can no longer download =
the versions of fop or batik that were used in creating the barcode4j =
jar files, maybe fop-0.20.5-patch2 and batik version 1.51.  I tried =
compiling the barcode4j code against the the older jars we have already, =
fop-0.20.5 and batik-1.5, that has some insurmountable problems.  So I =
downloaded and tried using the current versions, fop-0.20.5-patch3 and =
batik-1.6, and after getting past some of the obvious errors we =
evenutally get to some bizarre runtime exceptions about method =
signatures not matching (when clearly they passed the compiler AND =
looking at the method and the calling code it seems to match).  So to =
check if we can get barcode4j working within our appserver we copied the =
fop.jar and batik.jar from the barcode4j source lib directory, =
overwriting our previous versions, and barcodes come out just fine. =20

Unfortunately since we changed these versions it seems many other things =
are just off.  Margins and  scales seems to be wrong (e.g. you specify =
1.0in and you often get about 1.2in), SVG renderings that previously =
spanned an entire 8.5in page now are only 7.5ins, they are not major =
issues and could be accounted for but they are counter-intuitive AND =
we'd have to change many pages.  Are these bugs in the version of fop =
that is used or is it something else on our side?




-----Original Message-----
From: Jeremias Maerki [mailto:de...@je...]=20
Sent: Tuesday, November 22, 2005 12:00 PM
To: bar...@li...
Subject: Re: [Barcode4j-users] Using FOP extension from a web app

Ok, so you're Benny Anderson's colleague, judging from the e-mail =
address. :-)=20

Looks like a really tricky thing. To your question: I've already told =
Benny Anderson my ideas:
http://sourceforge.net/mailarchive/forum.php?thread_id=3D9027683&forum_id=
=3D38496

But I guess it hasn't helped, yet. There are no facilities to turn on =
logging especially for the ElementMapping. The only thing you can do is =
to add System.out statement in the FOP and Barcode4J source code and =
recompile it. Another idea I just had is trying FOP's example servlet =
found in the examples/servlet directory in the 0.20.5 distribution. That =
reduces the webapp to a minimum and should provide a reference point =
against your own webapp. Benny Anderson said you're working on Linux. If =
you have a Windows box around, please try the same there. Maybe it's a =
problem with the JDK in use, or maybe it's something with the web =
container. What web container are you using, BTW?

I'm sorry that I'm not able to help you more. If you solve this please =
let me know the solution. That you don't get any error messages at all =
is very disturbing because until now I've always received an error =
message if the Barocde4J Namespace is used in an FO document and FOP did =
not recognize the barcode extension.

The only work-around is to use the Xalan or SAXON extension during the =
XSLT stage to convert the barcode to an SVG graphic. Since for PDF =
Barcode4J does the same internally there's no performance penalty.

Good luck!

On 22.11.2005 20:09:34 Aaron Tavistock wrote:
> We're trying to get barcode4j working with our existing application=20
> which acts as a xsl-fo to PDF translator.  This part works fine, the=20
> xsl-fo is generated dynamically based on user requests and they get=20
> the results as a PDF file.
>=20
> Now we're trying to add some barcodes and barcode4j looks great,=20
> except we can't get it to integrate seemlessly.  We can generate a=20
> barcode from the command line and we can generate a barcode as an=20
> image using the the JavaBean within the app server.  Unfortunately,=20
> using the FOP extension is failing with no errors, no debug, and no=20
> results, we still get ALL the content outside the =
instream-foreign-object, just no barcodes.
>=20
> My first thought was that there is a classloader issue with the=20
> META-INF/services directory.  So I found the method for adding these=20
> by hand using driver.addElementMapping(ElementMapping) and added an=20
> instance of org.krysalis.barcode4j.fop0205.BarcodeElemenetMapping. =20
> This compiles (so the classes are clearly in the classpath) but there=20
> is no change, the results include all fop content except the barcode.
>=20
> Heres a snippet of the code:
>=20
>=20
>     ByteArrayOutputStream out =3D=20
>         new ByteArrayOutputStream();
>    =20
>     InputSource in =3D=20
>         new InputSource(new ByteArrayInputStream(rawContent));
>    =20
>     ElementMapping barcodeMapping =3D=20
>         new BarcodeElementMapping();
>=20
>     Driver driver =3D new Driver();
>     driver.setRenderer(Driver.RENDER_PDF);
>     driver.setLogger(logger);
>     driver.setInputSource(input);
>     driver.setOutputStream(out);
>     driver.addElementMapping(barcodeMapping)
>     driver.run();
>=20
>     byte[] content =3D out.toByteArray();
>=20
>=20
> First, does anyone have any ideas on resolving this?
>=20
> Second, is there a way to turn on explicit debuging for this element=20
> mapping?  Our logs show FOP starting, processing, and stopping as if=20
> there are no problems but theres no indication that the barcode=20
> mapping was accessed.
>=20
>=20
> -------------------------------------------------------
> This SF.Net email is sponsored by the JBoss Inc.  Get Certified Today=20
> Register for a JBoss Training Course.  Free Certification Exam for All =

> Training Attendees Through End of 2005. For more info visit:
> http://ads.osdn.com/?ad_idv28&alloc_id=16845&op=CCk
> _______________________________________________
> Barcode4j-users mailing list
> Bar...@li...
> https://lists.sourceforge.net/lists/listinfo/barcode4j-users



Jeremias Maerki