Another WebService returning VOTable

[Alberto Conti]

It might be of interest to some of you that the results of any search
in the MultiMission Archives at STScI also returns a VO table. These
are not Web-Services (i.e. no wsld files) but it's a quick and dirty
way to get VO-tables. 
Ultimately GALEX will add a XML web-services which also return
VO-TAbles.

http://archive.stsci.edu/data.html
http://galex.stsci.edu

Ciao,
Alberto

> -----Original Message-----
> From: owner-grid at eso.org [mailto:owner-grid at eso.org] On 
> Behalf Of Wil O'Mullane
> Sent: Friday, December 12, 2003 9:20 AM
> To: grid at ivoa.net
> Subject: Another WebService returning VOTable
> 
> actually now that I think back the SdssCOne is a webservice which
uses
> the HTTPget since thats what the protocol demands so you may also
try
> 
> http://skyservice.pha.jhu.edu/devel/ConeSearch/sdssConeSearch.
> asmx?wsdl
> 
> also returns VOTable ...
> 
> 
> On Fri, Dec 12, 2003 at 09:09:51AM -0500, Wil O'Mullane wrote:
> > May I suggest someone points ther java wsdl2java at something like

> > 
> >
http://skyservice.pha.jhu.edu/devel/CasService/CasService.asmx?wsdl
> > 
> > it returns a VOTable from 
> > GetVOtable
> > 
> > Pass it sql like 
> > 
> > select top 10 * from galaxy
> > 
> > 
> > That will give yo a VOTable set of Java classes and you 
> > will not have to parse the result ...
> > 
> > 
> > wil
> > On Fri, Dec 12, 2003 at 10:18:00AM +0000, Guy Rixon wrote:
> > > The question was raised at an AVO meeting "for a 
> web-service that returns a
> > > VOTable can the service return a Java object so we don't 
> have to parse the
> > > VOTable?"
> > > 
> > > Well, the web service itself is defined to return XML, so 
> it will return
> > > VOTable; it can't return Java directly. In any case, a 
> public service needs
> > > to support clients in many languages.
> > > 
> > > The conversion from VOTable to Java _has_ to be done in 
> the client, but there
> > > are three ways to do this:
> > > 
> > >  - make the author of the client application write the parser;
> > > 
> > >  - have the service publisher supply a stub that does the
parsing;
> > > 
> > >  - have the service publisher supply a delegate that does 
> the parsing.
> > > 
> > > Both stubs and delegates are classes in the programming 
> language that provide
> > > the function of the XML interface. They do serialization 
> of objects to XML and
> > > deserialization of objects from XML to the programming 
> language.  Stubs
> > > and delegates are both compiled into client programmes. Stubs
> > > and delegates operate at different levels of abtraction.
> > > 
> > > Stubs are low level.  They match the XML interface 
> closely.  Typically, a stub
> > > has one object method for each operation in the XML 
> interface. Arguments and
> > > return values of methods in the stub may be objects; the 
> stub maps these to
> > > XML fragments in the XML interface.  Stubs are usually 
> generated from WSDL by
> > > tools.  I.e. the inteface of a stub is usually fixed by 
> the XML interface.
> > > 
> > > Delegates are high level.  They are usually hand-coded.  
> The methods in a
> > > delegate class don't always map one-to-one with 
> operations in the WSDL.
> > > Arguments and return values of delegate classes don't 
> always map trivially to
> > > the structures in the XML interfaces.  I.e., the 
> interface of the delegate can
> > > be tuned to help the author of client applications.
> > > 
> > > A delegate can be written to call a stub.  This lets the 
> delegate use the
> > > tool-generated code in the stub and hence to be simpler.
> > > 
> > > Stubs are hard to produce and use when complex data 
> structures are being
> > > exchanged. They work best when all the objects that are 
> arguments or return
> > > values are Java beans (or the equivalent in other 
> languages): these can be
> > > serialized to and deserialized from XML by standard 
> libraries.  The fall-back
> > > position is to have the stub return a DOM: i.e. to do 
> only the lowest level of
> > > parsing of the XML.
> > > 
> > > Trying to generate stubs for services that return VOTable 
> is going to be hard.
> > > For the use case in the original question, it seems 
> sensible to provide a stub
> > > that returns a VOTable as a DOM and then provide a 
> delegate that calls the
> > > stub and returns the VOTable as an object, using a 
> VOTable-specific parser.
> > > 
> > > AstroGrid provides delegate classes in Java for its 
> services, and these are
> > > typically based on Java stubs made with Apache-Axis. 
> Authors of applications
> > > in other languages can still used the published XML 
> interfaces in their own
> > > stubs and delegates.
> > > 
> > > The XML interfaces remain the definitions of the 
> services.  Stubs and
> > > delegates are just helper classes to make things easier 
> for authors of
> > > clients.
> > > 
> > > Guy Rixon 				        
> gtr at ast.cam.ac.uk
> > > Institute of Astronomy   	                Tel: +44-1223-337542
> > > Madingley Road, Cambridge, UK, CB3 0HA		Fax: 
> +44-1223-337523
>