1. Web Services Dr. Herbert Praehofer Institute for System Software Johannes Kepler University Linz Dr. Dietrich Birngruber Software Architect TechTalk
© University of Linz, Institute for System Software, 2004
published under the Microsoft Curriculum License
Überblick

2. Web Services Introduction Web Services in .NET SOAP SOAP and .NET
Service Description with WSDL
Discovery of Web Services: UDDI and DISCO
Preview of Web Services .NET 2.0
Summary

3. Motivation Integration of heterogonous, distributed systems
globally distributed
different programming languages
different APIs
B2C and B2B applications
Usage of globally distributed services
Example: Travel Agent Service
taken from: Web Services Architecture Usage Scenarios, W3C Working Group Note, 11 February 2004,
Überblick

4. What are Web Services? Middleware for distributed applications
For remote procedure calls und data exchange
Open standard based on XML
For loosely coupled software services
Independent of programming languages and operating systems
Utilizing existing Internet protocols and server architectures
Überblick

5. Definition Web Service (by W3C)
Software application identified by URI
interface description in XML
with interaction on the basis of XML encoded messages
and message exchange on the basis of Internet protocols
Überblick

6. Independence and Integration through ...
SOAP
XML standard for message encoding
independent of transport protocol
independent of client and server implementations: Java, .NET, Python, …
Web Services Description Language - WSDL (1.1)
Interface description in XML
communication on the basis of existing protocols and server architectures
HTTP and Web server
SMTP and mail server
FTP and FTP server
Standardisation (W3C)
SOAP 1.2, WSDL 1.1 (1.2 und 2.0)
additional protocols based on SOAP and WSDL
protocol bindings (HTTP)
Überblick

7. Web Services Scenario
Überblick

8. Web Services in Comparison
Java RMI
.NET Remoting
CORBA
Web services
Programming language
Java
.NET languages (C#, VB.NET, ..)
independent
Interface definition
Java Interfaces
C# Interfaces
CORBA IDL
WSDL (XML-based)
Data structures
Java objects
.NET objects
IDL-specified objects
XML data
Transport protocol
RMI-IIOP
binary or OAP
GIOP/IIOP
HTTP, HTTPS, SMTP, FTP
Packaging
Java object serialisation
.NET object serialisation
ORB/CDR
SOAP
Infrastructure
Java RMI infrastructure
.NET remoting infrastructure
ORBs
Web, Mail, FTP server
Überblick

9. Pros and Cons
Pros
independent of programming language, run time environment and operating system
Built on existing Internet infrastructure
standardized
promoted from important players (Microsoft, IBM, SAP, Sun)
Cons
performance (XML)
Überblick

10. Web Service Infrastructure
Überblick

11. Web Service Architecture
Überblick

12. Web Service Architecture (2)
Überblick

13. Web Services Introduction Web Services in .NET SOAP SOAP and .NET
Service Description with WSDL
Discovery of Web Services: UDDI and DISCO
Preview of Web Services .NET 2.0
Summary

14. Web Services in .NET
IIS and ASP.NET infrastructure support web services
.NET Framework provides several
base classes
attributes
protocols
for the realization of web services
Visual Studio.NET provides powerful tools for developing web services
implementation
testing
administration of IIS
generation of proxy code (wsdl.exe)
Überblick

15. .NET Namespaces System.Web.Services System.Web.Services.Configuration
for developing web services (e.g.: WebService, WebMethod)
System.Web.Services.Configuration
for extending SOAP
System.Web.Services.Description
for creating and manipulating WSDL descriptions
System.Web.Services.Discovery
for using DISCO
System.Web.Services.Protocols
for implementation of communication protocols (e.g. SOAP-HTTP)
System.Xml.Serialization
for XML serialization
Überblick

16. Implementation of Web Services
WebService Language="C#" Class="MyWebService" %>
in asmx-file with @WebService directive
public class MyWebService : WebService {
deriving from base class System.Web.Services.WebService
[WebMethod(Description= “comment ")]
[…]
public Returntype MyWebMethod( …) { …
Identification and settings by .NET attributes
identification of web service methods
definition of format and encoding
XML namespaces and element names to use
etc.
Überblick

17. Example: TimeService TimeService.asmx WebService directive
WebService Language="C#" Class="TimeService" %>
using System;
using System.Web.Services;
public class TimeService : WebService {
[WebMethod(Description="Returns the current time")]
public string GetTime(bool shortForm) {
if (shortform) return DateTime.Now.ToShortTimeString();
else return DateTime.Now.ToLongTimeString(); }
WebService directive
deriving from WebService
Attribute [WebMethod] identifies web service method
Überblick

18. Example: Simple .NET Client
> wsdl.exe /namespace:TimeClient /out:TimeServiceProxy.cs
wsdl.exe generated proxy for client (TimeClient.TimeService)
using System;
using TimeClient; //Namespace des erzeugten Proxies
public class NetClient {
public static void Main(string[] args) {
TimeService service = new TimeService();
Console.WriteLine("Die Zeit am Server ist: ");
string time = service.GetTime(true);
Console.WriteLine(time); }
Client program creates TimeService object and calls GetTime
Überblick

19. Example: Simple Java Client
Using GLUE tool + Java libraries:
wsdl2Java create Java interface (ITimeServiceSoap) and proxy (TimeServiceHelper)
import Kapitel7.GLUEProxy.*; // import generated GLUE proxy classes
/** Simple XML web service client in Java using GLUE */
public class JavaClientGLUE {
public static void main(String[] args) {
try {
// Calling service using class and interface generated by wsdl2java
ITimeServiceSoap service = TimeServiceHelper.bind();
String time = service.GetTime(true);
System.out.println(“The time on the server is: \n" + time);
} catch (Exception ex) { ex.printStackTrace(); } }
Überblick

20. Web Services Introduction Web Services in .NET SOAP SOAP and .NET
Service Description with WSDL
Discovery of Web Services: UDDI and DISCO
Preview of Web Services .NET 2.0
Summary

21. SOAP Simple message protocol in XML Independent of transport protocol
for packaging arbitrary application data
single messages only („one-way“)
asynchronous
Independent of transport protocol
SOAP does not define:
distributed object model
communication protocol
distributed garbage collection
distributed events (distributed callbacks)
Überblick

22. Application of SOAP Client Server SOAP is extendable
method call protocol (RPC)
security
authentication
etc.
Protocol realisation by combination of messages (message exchange patterns)
one-way, request-response, multicast, …
Client
Server
e.g.: request-response for RPC by 2 messages
1: GetTime_Request
2: GetTime_Response
Überblick

23. SOAP Messages SOAP messages comparable to letters with
envelope (<Envelope>) as container
letter head (<Header>) with meta information (Message Headers)
letter (<Body>)
with arbitrary XML data
fault descriptions
Überblick

24. XML Structure (simplified, SOAP 1.2)
<?xml version="1.0" ?>
<soap:Envelope xmlns:soap="...">
<soap:Header> <!-- (optional and extendable)   -->  
<m:my xmlns:m="anURI" soap:mustUnderstand=“true" soap:role=“uri2" />  
...  
</soap:Header>
<soap:Body> 
data (depends on encoding and format)
<soap:Fault> 
<soap:Code>...who is responsible?... </Code>  
<soap:Reason>...textual description...</soap:Reason>
<soap:Detail>...more error details...</soap:Detail>
</soap:Fault> 
</soap:Body> 
</soap:Envelope>
Überblick

25. Data in <Body> Part
Message format:
document structure defined by XML schema
rpc structure defined by SOAP for RPC
Data encoding:
literal encoding defined by XML schema
encoded encoding defined by SOAP encoding rules
Usual combinations:
document/literal standard in .NET
rpc/encoded often used by Java servers
Überblick

26. HTTP Binding HTTP-GET, HTTP-POST
call encoded in HTTP (URL encoded)
response encoded in XML
Restricted to simple calls (no headers, no structured data)
SOAP over HTTP-POST
data part of POST request contains SOAP encoded call
response SOAP encoded
 No restrictions
Überblick

27. Example: HTTP-POST
Call of GetTime(bool shortForm) of web service
Call :
HTTP/ OK Content-Type: text/xml; charset=utf-8 Content-Length: length <?xml version="1.0" encoding="utf-8"?>
<string xmlns="
HTTP response:
Überblick

28. Example: SOAP over HTTP (1)
POST /time/TimeService.asmx HTTP/1.1
Content-type: text/xml; charset=utf-8
SOAPAction:
Content-length: 198
User-Agent: Java1.4.0
Host: localhost
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alive
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="
<soap:Body>
<GetTime xmlns="
<shortForm>
true
</shortForm>
< /GetTime>
</soap:Body>
</soap:Envelope>
SOAP over HTTP-POST:
HTTP-header SOAPAction identifies SOAP-request
Web method
Parameter
Überblick

29. Example: SOAP over HTTP (2)
SOAP encoded response:
HTTP/ OK Content-Type: text/xml; charset=utf-8 Content-Length: length <?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap=
xmlns:xsi=
xmlns:xsd="
<soap:Body>
<GetTimeResponse xmlns="
<GetTimeResult>string</GetTimeResult>
</GetTimeResponse>
</soap:Body>
</soap:Envelope>
Return value
Überblick

30. Web Services Introduction Web Services in .NET SOAP SOAP and .NET
Service Description with WSDL
Discovery of Web Services: UDDI and DISCO
Preview of Web Services .NET 2.0
Summary

31. SOAP and .NET .NET provides support for
defining message format and encoding
encoding of .NET data types
development of message headers
life cycle management
Überblick

32. Message Format and Encoding (1)
[SoapRpcMethod(Use=SoapBindingUse.Encoded
Action=" // SOAP action
RequestNamespace=" RequestElementName="AddAddressRpcRequest", // SOAP element name ResponseNamespace=" ResponseElementName="AddAddressRpcResponse")] // SOAP element name [WebMethod(Description="Adds an address DataSet for the specified user")] public void AddAddressRpc(long userID, Address address) { ... }
Attributes SoapRpcService and SoapRpcMethod for rpc format
with parameters
Use: encoding (SoapBindingUse.Literal or SoapBindingUse.Encoded)
Action: URI for SOAPAction-HTTP header
RequestNamespace and RequestElementName: namespace and name of SOAP element for request
ResponseNamespace and ResponseElementName: namespace and name of SOAP element for response
Überblick

33. Message Format and Encoding (2)
[SoapDocumentMethod(Use=SoapBindingUse.Literal,
Action=" // SOAPAction
RequestNamespace="
RequestElementName="AddAddressDocLitRequest", // SOAP element name ResponseNamespace=" ResponseElementName="AddAddressDocLitResponse")] // SOAP element name
[WebMethod(Description="Adds an address DataSet for the specified user")] public void AddAddressDocLit(long userID, Address address) { ... }
[SoapDocumentService(Use=SoapBindingUse.Encoded)]
public class TimeService : WebService { ... }
Attributes SoapDocumentService and SoapDocumentMethod for document format
Überblick

34. SOAP Encoding of .NET Data Types
Serializing of .NET data types
on the basis of SOAP encoding rules
adjusted by attributes (namespace System.Web.Serialization)
SoapAttributeAttribute
Serializing field as XML attribute
SoapElementAttribute
Serializing field as XML element
SoapIgnoreAttribute
No serialization of field
SoapIncludeAttribute
Including a type
SoapEnumAttribute
Adapting name of enumeration
Überblick

35. Example: Encoding of a Type (1)
Web method GetTimeDesc uses type TimeDesc for return value
[WebMethod(Description="Returns the time description of the server")]
public TimeDesc GetTimeDesc() {
TimeDesc td = new TimeDesc();
// ...
return td; }
public struct TimeDesc {
[SoapAttribute] public string TimeLong;
[SoapAttribute] public string TimeShort;
[SoapAttribute (AttributeName = "ZoneID")] public int TimeZone; }
Encoding of TimeDesc adjusted by attribute [SoapAttribute]  fields encoded as XML attributes
Überblick

36. Example: Encoding of a Type (2)
SOAP encoded response
...
<soap:Envelope xmlns:soap=" ...
<soap:Body soap:encodingStyle=" <types:GetTimeDescResponse>
<GetTimeDescResult href="#id1" />
</types:GetTimeDescResponse>
<types:TimeDesc id="id1" xsi:type="types:TimeDesc" types:TimeLong="10:00:25" types:TimeShort="10:00" types:ZoneID="1" />
</soap:Body>
</soap:Envelope>
Überblick

37. Including Types
SoapIncludeAttribute allows inclusion of types
 important for specializations
Example: PersonService
public class PersonService : WebService {
[WebMethod]…
public Person[ ] GetAll() {…} }
Web method with return value of type Person[]
Person
Customer
Employee
Person has 2 specializations Customer and Employee
 Customer and Employee have to be included explicitly into web service description!
Überblick

38. Example: PersonService (1)
Classes Person, Customer and Employee
public abstract class Person { …}
public class Customer : Person { …}
public class Employee : Person {…}
WebService Language="C#" Class="PersonService" %>
using System; … using System.Xml.Serialization;
public class PersonService : WebService {
[WebMethod] [SoapRpcMethod]
[SoapInclude(typeof(Customer)), SoapInclude(typeof(Employee))]
public Person[] GetAll() {
Person[] data = new Person[2];
data[0] = new Customer("1“, "Max Customer", "EMP-33");
data[1] = new Employee("EMP-33", "Tom Employee");
return data; }
PersonService defines web method GetAll with return type Person[]
SoapInclude attribute includes Customer and Employee types
Überblick

39. Example: PersonService (2)
SOAP encoded response
<soap:Envelope xmlns:soap=" ... >
<soap:Body soap:encodingStyle="
<tns:GetAllResponse>
<GetAllResult href="#id1" />
</tns:GetAllResponse>
<soapenc:Array id="id1" soapenc:arrayType="types:Person[2]">
<Item href="#id2" />
<Item href="#id3" />
</soapenc:Array>
<types:Customer id="id2" xsi:type="types:Customer">
<SSN xsi:type="xsd:string">1</SSN>
<Name xsi:type="xsd:string">Max Customer</Name>
<EmpSSN xsi:type="xsd:string">EMP-33</EmpSSN>
</types:Customer>
<types:Employee id="id3" xsi:type="types:Employee">
<SSN xsi:type="xsd:string">EMP-33</SSN>
<Name xsi:type="xsd:string">Tom Employee</Name>
</types:Employee>
</soap:Body>
</soap:Envelope>
Überblick

40. SOAP Header Entries
SOAP header entries are used for metainfos in messages
Arbitrary header entries are possible
All header entries have attributes
recipient of entry (Actor)
if it must be handled by recipient (mustUnderstand)
.NET supports header entries by:
Class SoapHeader: development of header entry classes
Attribute SoapHeaderAttribute: Defining header entries for web methods
Überblick

41. Classes SoapHeader and SoapHeaderAttribute
Recipient
Header must be handled
Header handled successfully
In-, Out-, InOut direction of headers
Name of field of web service class for header entry
public string Actor {get; set;}
public SoapHeaderDirection Direction {get; set;}
public bool MustUnderstand {get; set;}
public string MemberName {get; set;}
public bool DidUnderstand {get; set;}
Überblick

42. Example: AuthHeader (1)
User indentification in TimeService
Login returns identification code (cookie)
GetTime sends back identification code in header entry
Header class AuthHeader defines public field cookie
public class AuthHeader : SoapHeader { public string cookie; }
Web service class defines field curUser to store AuthHeader object
[WebService(Namespace="
public class HeaderTimeService : WebService {
public AuthHeader curUser;
Login with user and password returns identification string
[WebMethod (Description="Authenticates the user")]
public string Login(string user, string pwd) { ... create cookie ... }
bool ValidateCookie(string cookie) { ... validate cookie ... }
Überblick

43. Example: AuthHeader (2)
GetTime requires header entry of type AuthHeader which will be stored in field curUser
Validates user based on login data
[WebMethod(Description="Returns the current time")]
[SoapHeader("curUser")]
public string GetTime() {
if (curUser != null && ValidateCookie(curUser.cookie))
return System.DateTime.Now.ToLongTimeString();
else throw new SoapHeaderException("Access denied!",
SoapException.ClientFaultCode); }
Überblick

44. Example: AuthHeader (3)
Client
creates service proxy and AutHeader object
HeaderTimeService proxy = new HeaderTimeService();
AuthHeader entry = new AuthHeader();
receives cookie from call to Login
entry.cookie = proxy.Login(user, pwd);
sets the AuthorHeader in proxy
calls GetTime with AuthHeader header entry
entry.cookie = proxy.Login(user, pwd);
proxy.AuthHeaderValue = entry;
Console.WriteLine(proxy.GetTime());
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap=" ... >
<soap:Header>
<AuthHeader xmlns="
<cookie>aewt12348cvNNgrt55</cookie>
</AuthHeader>
</soap:Header>
<soap:Body>
<GetTime xmlns=" />
</soap:Body>
</soap:Envelope>
Überblick

45. Life Cycle Web service objects are stateless Are created for each call
Data can be stored in properties of
Application state object or
Sesssion state object
public HttpApplicationState Application {get;}
public HttpApplicationState Session {get;}
public sealed class HttpSessionState : ICollection, IEnumerable {
public object this[ string name ] {get; set;}
public object this[ int index ] {get; set;} … }
Überblick

46. Example: StateDemo (1)
WebService Language="C#" Class="StateDemo" %>
using System.Web.Services;
[WebService(Namespace="
public class StateDemo : WebService {
Web service StateDemo demonstrates storage of data
IncApplication increases property "Hit" of Application state object
[WebMethod()]
public int IncApplication() {
int hit = (Application["Hit"] == null) ? 0 : (int) Application["Hit"];
hit++;
Application["Hit"] = hit;
return hit; }
Überblick

47. Example: StateDemo (2)
Parameter EnableSession enables usage of Session object
IncSeesion increases property "Hit" of Session state object
[WebMethod(EnableSession=true)]
public int IncSession() {
int hit = (Session["Hit"] == null) ? 0 : (int) Session["Hit"];
hit++;
Session["Hit"] = hit;
return hit; }
Überblick

48. Web Services Introduction Web Services in .NET SOAP SOAP and .NET
Service Description with WSDL
Discovery of Web Services: UDDI and DISCO
Preview of Web Services .NET 2.0
Summary

49. Web Service Description Language (WSDL)
WSDL is an XML based IDL for web services
a WSD describes:
used data types
structure of messages
operations (methods)
protocols to call operations
addresses of web service
current version in .NET: WSDL 1.1 (
Working Draft: WSDL 2.0 (10/4/2004)
Überblick

50. Structure of WSDL 1.1 abstract part concrete part <definitions>
<types>
</types>
<message>
<part>
</part>
</message>
<portType>
<operation>
<input>
<output>
</operation>
</portType>
<binding>
</binding>
<service>
<port>
</service>
</definitions>
WSDL description of a web services
types defined in <xsd:schema>
simple messages
parts of messages
interface specification
operations of an interface
input message
output message
binding of interface to protocols and encoding
description of the binding for each operation
service description
URI and binding to port
concrete
part
Überblick

51. Example: WSDL for TimeService (1)
WSDL description created by web container (IIS)
<?xml version="1.0" encoding="utf-8"?>
<definitions xmlns:soap=
xmlns:tns="
xmlns:s="
xmlns:http="
xmlns:mime="
xmlns:soapenc="
targetNamespace="
xmlns="
<types />
<message name="GetTimeSoapIn" />
<message name="GetTimeSoapOut">
<part name="GetTimeResult" type="s:string" />
</message>
<portType name="TimeServiceSoap">
<operation name="GetTime">
<input message="tns:GetTimeSoapIn" />
<output message="tns:GetTimeSoapOut" />
</operation>
</portType> …
abstract part
Überblick

52. Example: WSDL for TimeService (2)…
<binding name="TimeServiceSoap" type="tns:TimeServiceSoap">
<soap:binding transport=" style="rpc" />
<operation name="GetTime">
<soap:operation soapAction=" style="rpc" />
<input>
<soap:body use="encoded" namespace="
encodingStyle=" />
</input>
<output>
</output>
</operation>
</binding>
<service name="TimeService">
<documentation>Simple web service for querying the time</documentation>
<port name="TimeServiceSoap" binding="tns:TimeServiceSoap">
<soap:address location=" />
</port>
</service>
</definitions>
concrete
part
Überblick

53. Web Services Introduction Web Services in .NET SOAP SOAP and .NET
Service Description with WSDL
Discovery of Web Services: UDDI and DISCO
Preview of Web Services .NET 2.0
Summary

54. Universal, Description, Discovery and Integration (UDDI)
Standardized protocol for searching for and using web services
Provides web services interface
Directory (UDDI)
1.) register
2.) search
Client
Web Service A
Web Service B
3.) connect
4.) call
Überblick

55. DISCO Microsoft’s technique for dynamic usage of web services
DISCO file
contains XML document with URIs pointing to web services
can be the result to a UDDI inquiry
.NET support in namespace System.Web.Services.Discovery
Überblick

56. DISCO Descriptions Creation of DISCO descriptions:
by command tool disco.exe
by IIS
> disco.exe /out:WebProject1 WebProject1/TimeService.asmx
<?xml version="1.0" encoding="utf-8" ?>
<discovery xmlns:xsd="
xmlns:xsi="
xmlns="
<contractRef ref="
docRef="
xmlns=" />
<soap address="
xmlns:q1=" binding="q1:TimeServiceSoap„
xmlns=" />
</discovery>
Überblick

57. Example: TimeService Discovery (1)
2 variants of TimeService
TimeService1
TimeService2
WebService Language="C#" Class="TimeService1" %>
using System.Web.Services;
[WebService(Namespace=" Name="TimeService")]
public class TimeService1 : WebService {
[WebMethod(Description="Returns the current server time")]
public string GetTime() { return System.DateTime.Now.ToLongTimeString(); } }
WebService Language="C#" Class="TimeService2" %>
using System.Web.Services;
[WebService(Namespace=" Name="TimeService")]
public class TimeService2 : WebService {
[WebMethod]
public string GetTime() { return "I don’t know the time!"; } }
Überblick

58. Example: TimeService Discovery (2)
Disco client with discovery of DISCO file
using System; using System.Web.Services.Discovery; using System.Collections;
public class DiscoSample {
public static void Main(string[] args) {
loading the DISCO files
DiscoveryClientProtocol discoClient = new DiscoveryClientProtocol();
foreach (string uri in args) {
discoClient.Discover(uri); }
iterating over all DISCO descriptions
discoClient.ResolveAll();
TimeService proxy = new TimeService();
foreach (object obj in discoClient.Documents.Values) {
DiscoveryDocument dDoc = obj as DiscoveryDocument;
Überblick

59. Example: TimeService Discovery (3)
iterating over all <contactRef>-elements and retrieve URLs
ContractReference contr = null;
IEnumerator it = dDoc.References.GetEnumerator();
while (contr == null && it.MoveNext())
contr = it.Current as ContractReference;
given URL connect to web service and call web method
if (contr != null) {
proxy.Url = contr.DocRef; Print("Connecting proxy to " + proxy.Url);
proxy.Discover();
Print("Result of GetTime: " + proxy.GetTime()); }
static void Print(string msg) { System.Console.WriteLine(msg); }
Überblick

60. Web Services Introduction Web Services in .NET SOAP SOAP and .NET
Service Description with WSDL
Discovery of Web Services: UDDI and DISCO
Preview of Web Services .NET 2.0
Summary

61. Indigo Web services in .NET 2.0 are integrated in Indigo Indigo unites
.NET remoting
Web services
.NET Enterprise Services
in one uniform programming model
Indigo provides
transactions
reliable communication
secure communication and authentication
independence of transport protocols
host independence
message-based server activation
Überblick

62. Indigo Architecture
Überblick

63. Indigo Web Service Example (1)
Implementation of web service TimeService
using System; using System.MessageBus.Services;
[DatagramPortType(Name="TimeService", Namespace="
public class TimeService {
[ServiceMethod]
public DateTime GetTime() {
DateTime now = DateTime.Now;
Console.WriteLine ("Time request at {0}", now); // output to monitor server
return now; }
Compiling and creation of assembly
csc /target:library /reference:System.MessageBus.dll TimeService.cs
Creating the WSDL description
wsdlgen TimeService.dll
Überblick

64. Indigo Web Service Example (2)
Implementation of the server application
using System; using System.MessageBus.Services; using System; using System.MessageBus;
class Server {
static void Main () {
ServiceEnvironment se = null;
try {
se = ServiceEnvironment.Load();
se.Open();
Console.WriteLine("Press enter to stop the service ...");
Console.ReadLine();
} finally { if (se != null) se.Close(); } }
Überblick

65. Indigo Web Service Example (3)
Configuration of the server in file Server.exe.config
<configuration>
<system.messagebus>
<serviceEnvironments>
<serviceEnvironment name="main">
<port>
<identityRole>
soap.tcp://localhost:12345/TimeService/
</identityRole>
</port>
<remove name="securityManager"/> <!-- Security disabled!!! -->
<policyManager>
<areUntrustedPolicyAttachmentsAccepted> true
</areUntrustedPolicyAttachmentsAccepted>
<isPolicyReturned> true </isPolicyReturned>
</policyManager>
<serviceManager>
<activatableServices>
<add type="TimeService, TimeService" />
</activatableServices>
</serviceManager>
</serviceEnvironment>
</serviceEnvironments>
</system.messagebus>
</configuration>
Überblick

66. Indigo Web Service Example (4)
Compilation of the server application
csc /reference:System.MessageBus.dll Server.cs
Creation of the proxy for the client
wsdlgen dotnet_jku_at.WS.wsdl dotnet_jku_at.WS.xsd
Compilation of the proxy code
csc /target:library /reference:System.MessageBus.dll dotnet_jku_at.WS.cs
Überblick

67. Indigo Web Service Example (5)
Implementation of the client application
using System; using System.MessageBus.Services;
public class Client {
public static void Main () {
ServiceEnvironment se = null;
try {
se = ServiceEnvironment.Load();
ServiceManager sm = se[typeof(ServiceManager)] as ServiceManager;
if (sm == null) throw new Exception("ServiceManager is not available.");
se.Open();
Uri uri = new Uri("soap.tcp://localhost:12345/TimeService/");
// get a channel to the web service from the default service manager
ITimeServiceChannel channel = (ITimeServiceChannel)
sm.CreateChannel(typeof(ITimeServiceChannel), uri);
Console.WriteLine(channel.GetTime());// invoke web service method
} catch (Exception e) { Console.WriteLine(e);
} finally { if (se != null) se.Close(); } }
Configuration of the client (analogous to the server) and compilation
csc /reference:System.MessageBus.dll,dotnet_jku_at.WS.dll Client.cs
Überblick

68. Indigo Web Service Example (6)
Starting the server and the client
//----- Server
> Host.exe
Press enter to stop the service ...
Time request at 1/29/2004 3:35:51 PM
>
//----- Client
> Client.exe
Time request at 1/29/2004 3:35:51 PM
>
Überblick

69. Web Services Introduction Web Services in .NET SOAP SOAP and .NET
Service Description with WSDL
Discovery of Web Services: UDDI and DISCO
Preview of Web Services .NET 2.0
Summary

70. Summary Web services are a middleware technology
on the basis of XM and Internet protocols
independent of programming language and run time system
for the integration of heterogeneous, distributed systems
.NET supports web services
development of web services
development of web service clients
discovery and dynamic connection to web services
In .NET 2.0 Indigo unites the different remoting technologies
Überblick

71. Resources (apart from dotnet.jku.at)
UDDI & Co
Homepage of UDDI initiative
www-3.ibm.com/services/uddi: Discovery service from IBM
uddi.microsoft.com: Discovery service from Microsoft
Catalogue with UDDI- und DISCO entries
For developers
Specifications
Articles and tutorials about web services
Site for .NET technology, including web services
groups.yahoo.com/group/soapbuilders: Discussion group for SOAP
Java implementations
xml.apache.org/axis/: Web service server in Java based on Apache
GLUE: web service server in Java
Überblick