Nick, to answer your question, I'll just forward a discussion I just had with James Strachan.
See below: ----- Original Message ----- From: "Nick Airey" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, April 12, 2002 4:08 AM Subject: Bean generator > > Hello everyone, > > I think it would be useful to have a "BeanGenerator", which basically > generates SAX events based on a java bean. > > I already have written several of these, customized according to various > java bean structures, but I see I am going to need more of them, so it > would be cool to replace all of these generators with a single generator > which uses bean introspection to generate SAX events. > > > In my case, the beans in question are value objects returned from EJB > middleware, and cocoon is doing all the presentation layer processing. > > > > My question is: does something like this exist already? I suspect not. > > If not, my second question is: does anyone know a good (open) framework > for converting beans to SAX events. I have been doing some research, and > have come across several projects: > > Betwixt > (http://cvs.apache.org/viewcvs/jakarta-commons-sandbox/betwixt/) > Looks promising, but doesn't (yet) have a SAX writer. > > Domify: > (http://domify.sourceforge.net/) > > Hammer: > (http://www.csse.monash.edu.au/~bren/Hammer/) > Stars in the WROX "Java XML" book, published 2001, chapter 6. > > > Can anyone comment on which would be a good way to go. Of course, if > this is considered to be generally useful, I would be happy to donate > the code for the resulting generator to the cocoon project. > > > Nick. ----- Original Message ----- From: "James Strachan" <[EMAIL PROTECTED]> To: "Jakarta Commons Developers List" <[EMAIL PROTECTED]> Sent: Monday, April 08, 2002 10:32 PM Subject: Re: [Question] Betwix & JAXB > Hi Ivelin > > From: "Ivelin Ivanov" <[EMAIL PROTECTED]> > > Is there a rundown available on the reasons why Betwix is developing in > > paralel with JAXB? > > Good question :-) > > > > I've used Castor for quite some time and have been happy with its > > performance. > > JAXB takes the approach that a DTD (and one day an XML schema) is used to > generate beans that can parse/output the XML, then you can derive from them > to add behaviour. > > Betwixt takes a different approach, that starting with any bean, it already > has a default XML representation; then betwixt can be customized with just > the differences you want (moving elements around, adding arbitrary extra XML > nestings, renaming elements/attributes etc). Then betwixt can parse XML > (using Digester, it essentially defaults digester rules) or output XML > straight away, then customize to make it esthetically nicer XML later. > > On the list of things planned are SAX reader/writers and a DOM > implementation using betwixt's mappings, then XSLT can be used on beans > (like the Maven project does). Also I should finally get around to using > Betwixt to add a bean Navigator to the Jaxen XPath engine. Betwixt > essentially mirrors the Introspector / BeanInfo classes from java.beans but > for mapping information of beans to XML, so there's an XMLIntrospector and > XMLBeanInfo etc. > > > Both the JAXB & betwixt approaches are equally valid; JAXB is useful if you > want some beans generated from some kind of XML 'schema', betwixt is better > if you already have the beans and want to customize what the XML looks like, > or to automatically default digester rules for you, then maybe customize > things later. > > So if you're starting from beans and want nice XML then betwixt is a good > tool for the job; if you're starting with a DTD and want to write some > beans, then look at JAXB. > > Castor is kinda in the middle between them with a bit more complexity thrown > in for good measure but its got some good stuff in there. Though I always > get the impression Castor is trying to do too much together at the same time > rather than just doing one thing well, but maybe thats just me. I can't help > think of the phrase 'jack of all trades and master of none'. e.g. Castor is > JDO-like without being compliant, its kind of an O/R mapping tool, its a > reasonable O/XML mapping tool and a kinda OQL engine all thrown in together. > An impressive body of work though. > > As an aside, betwixt focusses on the mapping metadata of how beans should > map to XML, so betwixt could maybe be used to generate Castor java <-> XML > bindings - though I'm not sure why you'd want to do that ;-) > > > > Apache Axis build their own JavaBean-XML mapping and Betwix is yet another > > development in the area. > > Its on my list to investigate using Betwixt in Axis. SOAP supports various > different encodings, 1 of which (usually called the 'soap encoding') is a > well defined mapping of SOAP to java objects, so Axis probably implements > that spec. > > However for some of the other encodings (such as none where you just get > XML), then maybe betwixt could be used to map a SOAP schema to some > implementation beans. i.e. to have a flexible, customizable mapping. > > I'd certainly like try out a Betwixt based serializer/deserializer for Axis > and see if it works neatly. > > James > > > _________________________________________________________ > Do You Yahoo!? > Get your free @yahoo.com address at http://mail.yahoo.com > > > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
