DISCO UDDI -Sandeep Gadde
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DISCO UDDI
-Sandeep Gadde
CONTENTS:
Web Services
What is DISCO?
Disco Client Utilities
Disco Redirects
Dynamic Discovery
UDDI
UDDI as a better DISCO
UDDI Repository
UDDI Binding Information
UDDI Programmer’s API
UDDI - Lite
WEB SERVICES
Web services are automated information services that
are conducted over the Internet, using standardized
technologies and formats/protocols that simplify the
exchange and integration of large amounts of data over
the Internet.
Web services platform elements are SOAP, UDDI, WSDL.
Web services use XML to code and decode data, SOAP
to transport data.
CONT..
Web Services basically uses HTTP and SOAP to make
business data available on the web and executes remote
function calls.
SAMPLE WEBSERVICE
namespace WebService1
{
[WebService(Namespace = "http://tempuri.org/")]
public class Service1 : System.Web.Services.WebService
{
[WebMethod]
public string HelloWorld()
{
return "Hello World";
}
[WebMethod]
public int add(int a, int b)
{
return a+b;
}
}
}
DISCO
Web Services discovery is the process of locating and
interrogating web service descriptions, which is a
preliminary step for accessing a web service.
Discovery file is an XML document with a .disco
extension and holds the Web Services information.
SAMPLE DISCO FILE
Service1.disco
<disco:discovery
xmlns:disco="http://schemas.xmlsoap.org/disco/"
xmlns:scl="http://schemas.xmlsoap.org/disco/scl/">
<!-- reference to other DISCO document -->
<disco: discoveryRef ref="related-services/default.disco"/>
<!-- reference to WSDL and documentation -->
<scl:contractRef ref=“Service1.asmx?wsdl“ docRef=“Service1.asmx"/>
</disco:discovery>
\MyService (root dir)
Service1.asmx
web.config
Service1.disco
\bin
simpleMath.dll
complexMath.dll
DISCO CLIENT UTILITIES
There are 2 types of client utilities to discover a
WebService.
- disco.exe tool
- Add web ref feature in visual studio.net
disco.exe tool is a command line utility provided by
microsoft sdk and it is used as follows.
c:\>disco.exe
http://localhost:85635/MyService/service1.disco
CONT..
An output file with name results.discomap is created
that contains information about web services discovered
at specified URL.
It also downloads all the .disco and .wsdl documents
that were discovered.
Wsdl.exe is the utility to generated web service proxies
from WSDL documents or the .discomap files generated
by disco.exe .
CONT..
results.discomap
<?xml version="1.0" encoding="utf-8"?>
<DiscoveryClientResultsFile
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Results>
<DiscoveryClientResult
referenceType=
"System.Web.Services.Discovery.ContractReference"
url="http://localhost/MyService/Service1.asmx?wsdl"
filename=“Service1.wsdl"/>
<DiscoveryClientResult
referenceType=
"System.Web.Services.Discovery.DiscoveryDocumentReference"
url="http://localhost/MyService/related-services/default.disco"
filename="default.disco" />
</Results>
</DiscoveryClientResultsFile>
CONT..
Add web reference feature in visual studio.net
CONT..
CONT..
DISCO REDIRECTS
Disco Redirects help to redirect to disco file, if the user
doesn’t know the exact address of the disco file.
Disco provide hints in the default page of root directory
If the root's default page is an HTML document, you can
use the LINK tag to redirect the client to the .disco file:
<HTML>
<HEAD>
<link type='text/xml' rel='alternate' href=‘Sample1.disco'/>
</HEAD>
•••
</HTML>
CONT..
If the root's default page is an XML document, you can
use the xml-stylesheet processing instruction to
accomplish the same thing:
<?xml-stylesheet type="text/xml" alternate="yes" href=“Service1.disco"?>
DYNAMIC DISCOVERY
Dynamic discovery is discovering web services
dynamically
To enable dynamic discovery, a .vsdisco file like the one
shown here must be placed in the desired root.
<dynamicDiscovery xmlns="urn:schemas-dynamicdiscovery:disco.2000-03-17“ />
Requests for .vsdisco files are handled by
System.WebServices.Discovery.DiscoveryRequestHandler
namespace, which dynamically generates a DISCO
document based on the resources found in the target
root directory.
UDDI
Universal Description, Discovery and Integration (UDDI)
is a specification for building distributed databases that
enable interested parties to “discover” each other’s
Web services.
Provides easy discovery, sharing, and reuse of Web
services and other programmable resources.
UDDI AS A BETTER DISCO
UDDI goes beyond DISCO by defining how to interact
with a full-fledged Web Service information repository.
UDDI specification consists of a programmer’s API along
with an XML schema definition of supporting data
structures and messages.
UDDI REPOSITORY
UDDI repositories contain information about
businesses, services, and service bindings as well
as additional metadata for categorization
purposes.
UDDI uses white pages, yellow pages, and green
pages to organize information
CONT..
White pages include business name, contact info.
Yellow pages include categories based on
standard taxonomies.
Green pages include the technical specifications
and references.
UDDI BINDING INFORMATION
UDDI registry contains 4 main types of information:
Business, Services, Binding Templates and tModels.
Business-Name, Contact Info, Technical Info of the service.
Service-Technical/Business descriptions & categorizations.
Each service also exposes binding template info that
describes how to connect to and communicate with the
given service.
UDDI PROGRAMMER’S API
UDDI Programmer’s API is divided as Inquiry API and
Publishing API.
Inquiry API: Provides operations for retrieving
information from the registry.
Publishing API: Provides operations for publishing
information to the registry.
INQUIRY API
Name
Description
Find_business
This locates information about one or more businesses.
Find_service
This locates services within a registered businessEntity.
Find_binding
This locates bindings within a registered businessService.
Get_businessDetail
This gets businessEntity information for one or more businesses.
Get_business DetailExt
This gets extended businessEntity information.
Get_serviceDetail
This gets full details for a set of registered businessServices.
Get_bindingDetail
This gets bindingTemplate information for making service
requests.
Get_tModelDetail
This gets details for a set of registered tModels.
<FIND_BUSINESS> EXAMPLE
The following code illustrates how to perform a business
lookup by the company's name.
<?xml version='1.0' encoding='utf-8'?>
<s:Envelope xmlns:s='http://schemas.xmlsoap.org/soap/envelope/'>
<s:Body>
<find_business generic="1.0" xmlns="urn:uddi-org:api">
<name>XXX</name>
</find_business>
</s:Body>
</s:Envelope>
CONT..
The result of the find_business operation is the info about its
services
<s:Envelope xmlns:s='http://schemas.xmlsoap.org/soap/envelope/'>
<s:Body>
<businessList generic="1.0" truncated="false" operator=“XXX" xmlns="urn:uddi-org:api">
<businessInfos>
<businessInfo businessKey="0076B468-EB27-42E5-AC09-9955CFF462A3">
<name>XXX</name>
<description xml:lang="en">Empowering people through great software...</description>
<serviceInfos>
<serviceInfo businessKey="0076B468-EB27-42E5-AC09-9955CFF462A3"
serviceKey="D2BC296A-723B-4C45-9ED4-494F9E53F1D1">
<name>UDDI Web Services</name>
</serviceInfo>
</serviceInfos>
</businessInfo>
…………
</businessInfos>
</businessList>
</s:Body>
</s:Envelope> .
PUBLISHING API
Name
Description
get_authToken
Requests an authentication token from an operator site.
get_registeredInfo
Requests information currently managed by the user.
save_business
Registers/updates a businessEntity.
save_service
Registers/updates a businessService.
save_binding
Registers/updates a bindingTemplate.
save_tModel
Registers/updates a tModel.
delete_business
Deletes a businessEntity from the registry.
delete_service
Deletes a businessService from the registry.
delete_binding
Deletes a bindingTemplate from the registry.
delete_tModel
Deletes a tModel from the registry.
discard_authToken
Discards an existing authentication token.
<SAVE_BUSINESS> EXAMPLE
<?xml version='1.0' encoding='utf-8'?>
<s:Envelope xmlns:s= 'http://schemas.xmlsoap.org/soap/envelope/'>
<s:Body>
<save_business generic="1.0" xmlns="urn:uddi-org:api">
<!-- retrieved from get_authToken API -->
<authinfo>fd3c7a44-118f-413a-a2e3-473a35379993 </authinfo>
<businessEntity businessKey="ee3be846-d828-4a38-a5e4-3c33f931d122">
<name>Developmentor</name>
<description>Services the developer by... </description>
<businessServices>
<!-- service descriptions go here -->
</businessServices>
</businessEntity>
</save_business>
</s:Body>
</s:Envelope>
UDDI-LITE
Microsoft has come up with UDDI-Lite recently, a
compromise between DISCO and UDDI.
The idea behind this sample was to provide a centralized
web service repository that would be easy to maintain,
and would integrate with all of the existing .NET DISCObased tools.
CONT..
To implement UDDI-Lite
-Web Services are stored in SQL Server DB.
-ASP.NET front end to register and unregister Web
Services.
When client requests .vsdisco file, it automatically
generates information stored in SQL Server by mapping
requests using System.Web.UI.PageHandlerFactory class.
CONT..
SAMPLE CODE TO IMPLEMENT UDDI-LITE
<%@ page language="C#" contenttype="text/xml" enablesessionstate="false" %>
<%@ import namespace="System.Data" %>
<%@ import namespace="System.Data.SqlClient" %>
<% Response.ContentType = "text/xml"; %> <disco:discovery xmlns:disco="http://schemas.xmlsoap.org/disco/"
xmlns:scl="http://schemas.xmlsoap.org/disco/scl/">
<% SqlConnection conn = new SqlConnection("data source=localhost;initial catalog=uddilite;user id=sa;pwd="); conn.Open();
try
{
SqlCommand cmd = new SqlCommand("select contract, documentation from contracts");
cmd.Connection = conn;
IDataReader reader = null;
reader = cmd.ExecuteReader();
while (reader.Read())
{
%>
<scl:contractRef ref="<%= reader[0].ToString() %>
" docRef="<%= reader[1].ToString() %>" />
<% }
}
finally
{
conn.Close();
}
%>
</disco:discovery>
CONCLUSION
DISCO is ultimately limited by the type and depth of the
information that it provides.
Microsoft has been heavily involved in the development
of UDDI, which is receiving a lot of attention.
The bottom line is that DISCO works today and it can
help us to get more out of .NET Web Services with little
effort. For the future, look for UDDI developments.
REFERENCES
http://msdn.microsoft.com/en-us/magazine/cc302073.aspx
http://www.cs.odu.edu/~mukka/cs795sum10.net/Lecturenotes/d
ay4/wsuddi.ppt
http://uddi.xml.org/uddi-org
THANK YOU
