Transcript How to Publish and Find WSDL Service Descriptions in a

WSDL Tutorial
Heather Kreger (borrowed from Peter Brittenham)
Web Services Architect
IBM Emerging Technologies
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WSDL: Web Service Description Language
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Standard for describing Web services
 Abstract interface for defining operations and their
messages
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Messages contain either document-oriented or procedureoriented information
Bindings to message formats and protocols
Defines how to locate the endpoint for the service
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Example: URLs for HTTP
Extensible (SOAP and HTTP extensions are defined)
 Written in XML, leverages XML schema
WSDL V1.1 Specification
 http://www.w3.org/TR/wsdl
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Usage Scenarios
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As IDL (Interface Definition Language)
 Allows tools to generate client access code for a
service
 Examples: IBM WebSphere Studio Application
Developer, IBM Web Services Toolkit
Standardized service interface descriptions
 Allows advertisement and dynamic discovery of
services
 Enables dynamic binding to service
 Complements UDDI registry
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Document Content
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Abstract Definitions
 <types>
data type definitions
 <message> operation parameters
 <portType> operation definitions
Concrete Definitions
 <binding>
operation bindings
 <service>
location/address for each binding
Also:
 <import>
used to reference other XML documents
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WSDL Extensibility Elements
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Extensibility elements can be specified within these
WSDL elements:
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<types>
<port>
<binding>
<binding>/<operation>
<binding>/<operation>/<input>
<binding>/<operation>/<output>
<binding>/<operation>/<fault>
Binding extensibility defined in the specification for:
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SOAP
HTTP
MIME
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Document Structure
<binding>
[SOAP]
<service>
<port>
<port>
<port>
<binding>
[EJB]
<portType>
<operation>
<operation>
<operation>
<message>
[Request]
Java class
method
method
method
SOAP
Request/
response
<types>
[data]
<message>
[Response]
<binding>
[…]
Service(s)
Supported
Protocol(s)
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SOAP Binding - RPC Style
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Indicates that the Web service is accessed using
SOAP V1.1 protocol
Use style="rpc" attribute on SOAP binding element
Example SOAP service method signature:
 public float getQuote (String symbol)
SOAP
Java
Description
Operation
getQuote
Method name
Input Message
String symbol
Input parameter
Output Message
float
Return type
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Example: Stock Quote Service [1]
<definitions name="StockQuoteService"
targetNamespace="http://tempuri.org/StockQuoteService“
xmlns:tns="http://tempuri.org/StockQuoteService" …>
<message name="SymbolRequest">
<part name="symbol" type="xsd:string" />
</message>
public float
getQuote (String symbol)
<message name="QuoteResponse">
<part name="quote" type="xsd:float" />
</message>
public float
getQuote (String symbol)
<portType name="StockQuoteService">
<operation name="getQuote">
<input message="tns:SymbolRequest" />
<output message="tns:QuoteResponse" />
</operation>
public float
</portType>
...
getQuote (String symbol)
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Example: Stock Quote Service [2]
...
<binding name="SoapBinding" type="tns:StockQuoteService">
<soap:binding style="rpc"
transport="http://schemas.xmlsoap.org/soap/http" />
<operation name="getQuote">
<soap:operation soapAction="http://tempuri.org/GetQuote" />
<input>
<soap:body use="encoded"
namespace="http://tempuri.org/live-stock-quotes"
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</input>
<output>
<soap:body use="encoded" namespace="…" encodingStyle="…"/>
</output>
</operation>
</binding>
...
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Example: Stock Quote Service [3]
…
<service name="StockQuoteService">
<documentation>Stock Quote Service</documentation> <port name="Demo“ binding=“tns:SoapBinding">
<soap:address
location="http://tempuri.org/services/StockQuoteService" />
</port>
</service>
</definitions>
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Message
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Defines the messages that are referenced in the
input, output, and fault elements within an operation
A message may have one or more parts
Each part contains a reference to a data type
 element
Reference to XML Schema element
using a QName
 type
Reference to XML Schema
simpleType or complexType
<definitions .... >
<message name="ncname"> *
<part name="nmtoken" element="qname"? type="qname"?/> *
</message>
</definitions>
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PortType
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Contains one or more abstract operations
 Each operation references one or more messages
Four operation types:
 One-way
Send message to service and
there is no response
 Request-response
Send message to service which
returns a correlated message
 Solicit-response
Service sends a message and
requestor returns a correlated
message
 Notification
Service sends a message to
the requestor
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PortType
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One-way Operation
<portType name="ncname"> *
<operation name="nmtoken"> *
<input name="nmtoken"? message="qname"/>
</operation>
</portType >
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Request-response Operation
<portType name="ncname"> *
<operation name="nmtoken" parameterOrder="nmtokens"> *
<input name="nmtoken"? message="qname"/>
<output name="nmtoken"? message="qname"/>
<fault name="nmtoken" message="qname"/>*
</operation>
</portType >
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Binding
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Each binding
has an unique
name
 Referenced
by a port
element
Contains a
reference to
one portType
Binding
interpreted
based on
ext. elements
<binding name="ncname" type="qname"> *
<-- extensibility element (1) --> *
<operation name="nmtoken"> *
<-- extensibility element (2) --> *
<input name="nmtoken"? > ?
<-- extensibility element (3) -->
</input>
<output name="nmtoken"? > ?
<-- extensibility element (4) --> *
</output>
<fault name="nmtoken"> *
<-- extensibility element (5) --> *
</fault>
</operation>
</binding>
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Service
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A WSDL document may contain one or more service
elements
 Each service element may contain one or more ports
A port is named, references one binding, and
contains the endpoint for the Web service
 Port names must be unique within a service element
 Endpoint is specified using an extensibility element
<definitions .... >
<service name="ncname"> *
<port name="nmtoken" binding="qname"> *
<-- extensibility element (1) -->
</port>
</service>
</definitions>
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Complex Type Definitions
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Complex data types
 Defined within the <types> element or by referencing
an external XML schema document
AddressBook Example:
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public void addEntry(String name, Address address)
<schema ...>
<complexType name="AddressType">
<sequence>
<element name="streetName" type="string" minOccurs="1"/>
<element name="city" type="string" minOccurs="1"/>
<element name="state" type="string" minOccurs="1"/>
<element name="zip" type="string" minOccurs="1"/>
<element name="phoneNumber" type="AddressBook:phoneNumberType"/>
</sequence>
</complexType>
...
</schema>
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AddressBook Service
<definitions ...>
<import location="http://localhost:8080/schema/AddressBook.xsd"
namespace="http://tempuri.org/AddressBook”/>
<message name="AddEntryRequest">
<part name="name" type="xsd:string"/>
<part name="address" type="types:AddressType"/>
</message>
<portType name="AddressBookService">
<operation name="addEntry">
<input message="tns:AddEntryRequest"/>
</operation>
</portType
<binding name="AddressBookBinding" type="tns:AddressBookService">
<soap:binding style="rpc" transport="http://.../soap/http"/>
<operation name="addEntry">
<soap:operation soapAction="http://tempuri.org/addressbook"/>
<input>
<soap:body encodingStyle="..." namespace="..." use="..."/>
</input>
...
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SOAP Binding - Document Style
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Similar to SOAP Binding with RPC Style
 SOAP binding contains style=“document” attribute
 This style can also be set on a SOAP body element
which is specified with each operation element
Used with Web services that specify XML
documents for message content
 Example: UDDI Registry
<?xml version="1.0"?>
<SOAP-ENV:Envelope …>
<SOAP-ENV:Body>
<find_business generic="2.0" xmlns="urn:uddi-org:api_v2">
<name>Business Name</name>
</find_business>
</ SOAP-ENV:Body>
</SOAP-ENV:Envelope>
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WSDL for UDDI Registry [1]
<?xml version="1.0" encoding="UTF-8" ?>
<definitions targetNamespace="urn:uddi-org:inquiry"
xmlns:uddi="urn:uddi-org:api_v2"
xmlns:tns="urn:uddi-org:inquiry_v2" ...>
<import namespace="urn:uddi-org:api"
location="http://www.uddi.org/schema/uddi_v2.xsd" />
<message name="find_business">
<part name="body" element="uddi:find_business" />
</message>
...
<portType name="InquireSoap">
<operation name="find_business">
<input message="tns:find_business" />
<output message="tns:businessList" />
<fault name="error" message="tns:dispositionReport" />
</operation>
...
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WSDL for UDDI Registry [2]
<binding name="InquireSoap" type="tns:InquireSoap">
<soap:binding style="document"
transport="http://schemas.xmlsoap.org/soap/http" />
<operation name="find_business">
<soap:operation soapAction="" style="document" />
<input message="tns:find_business">
<soap:body use="literal" parts="body"
namespace="urn:uddi-org:api_v2" />
</input>
<output message="tns:businessDetail">
<soap:body use="literal" parts="body" namespace="urn:uddi-org:api_v2" />
</output>
<fault name="error" message="tns:dispositionReport">
<soap:fault name="error" use="literal" />
</fault>
</operation>
...
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MIME Binding
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Examples of supported MIME types:
 multipart/related
 text/xml
 application/x-www-form-urlencoded
Input or output message can be defined using MIME
binding
MIME binding can be combined with SOAP binding
to define a service that uses SOAP attachments
 Use multipart/related binding
 SOAP envelope must be in the root part
 Define other parts using MIME binding
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Attachment Service Interface [1]
<definitions name="AttachmentService-interface" ...>
<types>
<schema ...>
<complexType name="ArrayOfString">
<complexContent>
<restriction base="soapenc:Array">
<attribute ref="soapenc:arrayType“ arrayType="xsd:string[]"/>
</restriction>
</complexContent>
</complexType>
<complexType name="ArrayOfBinary">
<complexContent>
<restriction base="soapenc:Array">
<attribute ref="soapenc:arrayType" arrayType="xsd:binary[]"/>
</restriction>
</complexContent>
</complexType>
</schema>
</types>
...
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Attachment Service Interface [2]
<message name="AttachmentRequest">
<part name="fileList" type="types:ArrayOfString"/>
<part name="classFile" type="types:ArrayOfBinary"/>
<part name="imageFile" type=”types:ArrayOfBinary"/>
</message>
<message name= ="AttachmentResponse">
<part name="list" type="xsd:string"/>
</message>
<portType name="AttachmentService">
<operation name="listAttachments">
<input message="tns:AttachmentRequest"/>
<output message="tns:AttachmentResponse"/>
</operation>
</portType>
<binding name="AttachmentBinding" type="tns:AttachmentService">
<soap:binding style="rpc" transport="http://.../soap/http"/>
<operation name="listAttachments">
<soap:operation soapAction=""/>
...
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Attachment Service Interface [3]
<input>
<mime:multipartRelated>
<mime:part>
<soap:body parts="fileList" use="encoded"
namespace="http://tempuri.org/attachment-service"
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</mime:part>
<mime:part>
<mime:content part="classFile" type="application/octet-stream"/>
</mime:part>
<mime:part>
<mime:content part="imageFile" type="image/jpeg"/>
</mime:part>
</mime:multipartRelated>
</input>
<output>
<soap:body use="encoded“
namespace=“http://tempuri.org/attachment-service"
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</output>
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WSDL4J
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WSDL Java API
 WSDL object model
 Parse contents of a WSDL document
 Programmatically create new WSDL documents
Open source project on IBM developerWorks site
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http://oss.software.ibm.com/developerworks/projects/wsdl4j/
Will be a reference implementation for JSR 110
 Primarily a set of Java interfaces that can be
implemented by anyone
 Java package name: javax.wsdl
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WSDL4J Example - Find Port
// Get WSDLReader
WSDLReader wsdlReader = WSDLFactory.newInstance().newWSDLReader();
// Read WSDL service implementation document
Definition wsdlDefinition = wsdlReader.readWSDL(null, wsdlURL);
// Get the service elements
Map services = definition.getServices();
// Get an iterator for the list of services
Iterator serviceIterator = services.values().iterator();
boolean bPortFound = false;
while ((serviceIterator.hasNext()) && !(bPortFound)) {
// Get next service element
Service service = (Service) serviceIterator.next();
// Determine if this service element contains the specified port
if ((port = service.getPort(portName)) != null)
bPortFound = true;
}
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WSDL Resources
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WSDL V1.1 Specification
 http://www.w3.org/TR/wsdl
W3C Web Services Description Working Group
 http://www.w3c.org/2002/ws/desc/
WSDL4J Open Source Project
 http://oss.software.ibm.com/developerworks/projects/
wsdl4j/
Yahoo Group: wsdl
 http://groups.yahoo.com/group/wsdl
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An Overview of Web Services – Part 2
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Questions?
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