This document provides an overview of service oriented architecture (SOA) and web services. It defines SOA as an architectural style that promotes loose coupling between components. The key benefits of SOA include flexibility, reusability, and the ability to integrate systems. Web services are described as a standard way to implement SOA using XML, SOAP, WSDL and UDDI. The roles of a service, consumer and provider in SOA are also outlined.

1. Service Oriented Architectureand Web servicesMohammed LuqmanShareef

2. COM, DCOM Microsoft specificEJB, RMI Java SpecificCORBA Platform and Language Independent2010-02-082Popular Distributed Application Frameworks/Technologies

3. A software system is divided into highly flexible and re-usable components called services. SOA is just an architecture blue print It is NOT a technical standardIt is NOT a technology2010-02-083What is SOA?SOA is an architectural style of building software applications that promotes loose coupling between components for their reuse.Coarse grainedLoosely coupledPlatform independentStandard Interface

4. Self-contained module that perform a predetermined taskSoftware component that have published contracts/interfacesBlack-box to the consumersPlatform-IndependentInteroperable2010-02-084What is Service ?

5. Systems today are bigger than ever beforeComplexity increases exponentially with sizeSystems need to be interconnectedOO solved the problems of small-medium sized systemsCO (Component Orientation) solved problems of medium-large systemsNeither OO nor CO could cope with the problems of very large systems, systems of systems, or integration between systemsWhy SOA?

6. 2010-02-086Why SOA?End Customer PortalOperator PortalPartner PortalCustomer InfoManagementOrder ManagementCredit ManagementSalesManagementBillingLets take a telecom enterprise systemInvoicingProvisioningNetwork ManagementInventoryServiceCatalogCustomer Profiles

7. 2010-02-087Why SOA?End Customer PortalOperator PortalPartner PortalServicesCredit ManagementSalesManagementCustomer InfoManagementOrder ManagementProvisioningInvoicingInventoryNetwork ManagementCustomer ProfilesBillingServiceCatalog

8. Towards Service-Oriented ArchitectureCoordination oriented

9. Build to change

10. Incrementally built and deployed

11. Enterprise solutions

12. Loosely coupled

13. Message oriented

14. Abstraction

15. Function oriented

16. Build to last

17. Prolonged development cycles

18. Application silos

19. Tightly coupled

20. Object oriented

21. Known implementationManaging servicesService governancePerformanceReliabilitysecuritySLAsInteroperability of servicesChallenges

22. Loose couplingMinimize dependencies.Service contractServices adhere to a communications agreement.Service abstraction Hide the service execution logic from the outside world.Service reusabilityLogic is divided into services for reuse.2010-02-0810SOA: Architectural Principles

23. Service composabilityServices can be assembled to form composite service.Service autonomyServices have control over the logic they encapsulate.Service discoverabilityServices can be found and assessed via available discovery mechanisms.Service relevance Service presented at a granularity recognized by user a meaningful service.2010-02-0811SOA: Architectural Principles

24. SOA can be implemented using any service based technology such as CORBA, but the SOAP based web services standard implementation has gained wide industry acceptance, because these standards provide greater interoperability. Key differences between CORBA and web service are2010-02-0812SOA Implementation

25. 2010-02-0813Realizing SOA with Web Services

26. Web service is a standard way of integrating Web-based applications using the XML, SOAP, WSDL and UDDI open standards over an Internet protocol backbone. XML is used to tag the data, SOAP is used to transfer the data, WSDL is used for describing the services available and UDDI is used for listing what services are available. Web services are loosely coupled computing services that can reduce the complexity of building business applications, save costs, and enable new business models. Services running on an arbitrary machine can be accessed in a platform- and language-independent fashion.2010-02-0814What is web service ?

27. Lookup for the tomato sellersYellow Pages: contain companies that are selling tomatoes, their location, and contact information. 2010-02-0815How to buy tomatoes ?Find the service offered according to my needsWhere, when and how can I buy tomatoes? Buy the tomatoesDo the transaction

28. Lookup for the Service ProviderRegistry: contain providers that are selling services, their location, and contact information. Find the service offered according to my needsWhere, when and how can I get the service? Access the servicedo the transaction 2010-02-0816How to access a service?

29. XML (eXtensibleMarkup Language)A uniform data representation and exchange mechanismSOAP (Simple Object Access Protocol)Lightweight (XML-based) protocol for exchange of information in a decentralized, distributed environmentWSDL (Web Service Description Language)XML format that describes the web serviceUDDI (Universal Description Discovery and Integration)Like yellow pages of Web services2010-02-0817Components of a web service

30. 2010-02-08183 roles of service

31. 2010-02-0819Service Vs. ConsumerPolicyAdheres togoverned byEnd PointBinds toExposesServesService ConsumerServiceContractsimplementsUnderstandsdescribesMessagesSends/ReceivesSends/Receives

32. Define the service implementation and compile it. \WS>javac -d . HelloImpl.javaUse wsgen to generate the artifacts required to deploy the service. \WS>wsgen -wsdlserver.HelloImpl3. Package the files into a WAR file and deploy it .2010-02-0820Steps to develop a web serviceusing JAX-WSpackage server;import javax.jws.WebService;@WebServicepublic class HelloImpl { /** * @param name * @return Say hello to the person. */ public String sayHello(String name) { return "Hello, " + name + "!"; }}

33. 2010-02-0821HelloImplService.wsdl

34. 2010-02-0822HelloImplService.wsdl contd…

35. 2010-02-0823HelloImplService_schema1.xsd

36. Implement Client Code5. Use wsimport to generate and compile the web service artifacts needed to connect to the service. \WS>wsimportHelloImplService.wsdl parsing WSDL... generating code... compiling code...6. Run the client.2010-02-0824Steps to develop a web service contd…package myClient;import helloservice.endpoint.HelloService;import helloservice.endpoint.Hello;public class HelloClient { public static void main(String[] args) { try {HelloService service = new HelloService(); Hello port = service.getHelloPort(); String response = port.sayHello(“Luqman");System.out.println(response); } catch (Exception e) {e.printStackTrace(); } }}

37. WSDL is a contract between service provider and the consumerA WSDL document describesWhat the service can doWhere it residesHow to invoke it2010-02-0825WSDLWSDL elementsTypesMessageOperationPort TypeWSDLBindingPortService

38. Types Data type definition used in exchanging messagesMessage Describes the logical content of data being communicatedOperation An Abstract description of an action supported by the servicePort Type A set of operations and messages involved with the serviceBinding A concrete protocol and data format specification for a port typePort A single end point defined as a combination of a binding and a network addressService Identifies which ports to group together2010-02-0826WSDL elements

39. 2010-02-0827SOAPSOAP EnvelopeSOAP HeaderHeader BlockSOAP BodyMessage BodyFault HandlersSOAP message structureSOAP is a lightweight (XML-based) protocol for exchange of information in a decentralized, distributed environment. SOAP is a format for sending messagesSOAP is independent of transport protocolA SOAP message is an ordinary XML document containing the following elements:Envelope - identifies the XML document as a SOAP messageHeader - contains application specific info like authentication etc.Body - contains the message in request and responseFault - contains errors and status information

40. <?xml version="1.0"?><soap:Envelopexmlns:soap="http://www.w3.org/2001/12/soap-envelope"soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding"><soap:Bodyxmlns:m="http://www.example.org/Hello"> <m:sayHello> <m:name>Luqman</m:name> </m:sayHello></soap:Body></soap:Envelope> 2010-02-0828SOAP ExampleRequestResponse<?xml version="1.0"?><soap:Envelopexmlns:soap="http://www.w3.org/2001/12/soap-envelope"soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding"><soap:Bodyxmlns:m="http://www.example.org/stock"> <m:sayHelloResponse> <m:return>Hello Luqman</m:return> </m:sayHelloResponse></soap:Body></soap:Envelope>

41. SOAP errors are handled using a specialised envelope known as a Fault EnvelopeA SOAP Fault is a special element which must appear as an immediate child of the body element<faultcode> and <faultstring> are required.2010-02-0829SOAP Fault

42. Printing SOAP Messagepublic class MySOAPHandler implements SOAPHandler<SOAPMessageContext>{ public booleanhandleMessage(SOAPMessageContext context) { try {SOAPMessage message = context.getMessage(); if ((Boolean)context.get(MessageContext.MESSAGE_OUTBOUND_PROPERTY) == true){System.out.println("Request Message: "); }else{System.out.println("Response Message: "); }message.writeTo(System.out); } catch (Exception ex) {ex.printStackTrace(); } return true; } public Set<QName> getHeaders() { return null; } public booleanhandleFault(SOAPMessageContext context) { return true; } public void close(MessageContext context) { }}Wite a new Class MySOAPHandlerImplement handleMessage

43. Printing SOAP Message contd...public class MyMessageHandlerResolver implements HandlerResolver { public List<Handler> getHandlerChain(PortInfoportInfo) { List<Handler> handlerChain = new ArrayList<Handler>();MySOAPHandlerhh = new MySOAPHandler();handlerChain.add(hh); return handlerChain; }}Wite a new Class MyHandlerResolverImplement getHandleChainSet the Handler Resolver in ClientInvoke the web methodRun the clientservice.setHandlerResolver(new MyMessageHandlerResolver());

44. UDDI is a set of specifications that is used to publish information for describing and discovering web services, finding businesses, building registries. UDDI is a directory for storing information about web services.UDDI communicates via SOAP.2010-02-0832UDDI3 levels of information in UDDIWhite PagesTo query companies with their names and attributesYellow PagesTo query businesses with their categoriesGreen PagesContains technical info on how to interact with the services

45. 2010-02-0833UDDI Structure

46. 2010-02-0834Registry APIs (SOAP Messages)Publishers API

47. Save things

48. save_business

49. save_service

50. save_binding

51. save_tModel

52. Delete things

53. delete_business

54. delete_service

55. delete_binding

56. delete_tModel

57. security…

58. get_authToken

59. discard_authToken

60. Inquiry API

61. Find things

62. find_business

63. find_service

64. find_binding

65. find_tModel

66. Get Details about things

67. get_businessDetail

68. get_serviceDetail

69. get_bindingDetail

70. get_tModelDetailWrite the implementation and interfaceGenerate WSDL file>java org.apache.axis.wsdl.Java2WSDL -o AdderWSDL.wsdl -l http://localhost:8080/axis/services/Adder luqman.AdderInterfaceGenerate server side and client side classes>java org.apache.axis.wsdl.WSDL2Java -o . -p luqman.generated -s AdderWSDL.wsdlBind web service with functionality providerBundle required classesjar cfv adderServerSide.jar luqman\*.class luqman\generated\*.classCopy the jar in the server’s axis/WEB-INF/lib folder>jar cfv adderClientSide.jar luqman\generated\AdderInterface.classluqman\generated\AdderInterfaceService.classluqman\generated\AdderInterfaceServiceLocator.classluqman\generated\AdderSoapBindingStub.classRegister web services with Axisjava org.apache.axis.client.AdminClientluqman\generated\deploy.wsddWrite Web service clientDeveloping a web service using Axis

71. Printing SOAP Message in AXISEdit the generated code in AdderSoapBindingStub.class - In the corresponding method of the Stub class add the following lines of code after the _call.invoke(...) statementString requestMessage = _call.getMessageContext().getRequestMessage().getSOAPEnvelope().toString(); String responseMessage = _call.getMessageContext().getResponseMessage().getSOAPEnvelope().toString(); System.out.println(“Request SOAP Message” + requestMessage);System.out.println(“Request SOAP Message” + responseMessage);

72. Adding attachments to SOAP Message in AXISClient Side CodeCalculatorService service = new CalculatorServiceLocator();Calculator calc = service.getcalculator();Stub stub = (Stub) calc;FileDataSourcefs = new FileDataSource(new File("E:/Code/testA.txt") );DataHandler dh = new DataHandler(fs);stub.addAttachment(dh);Display the Attachment in StubEdit the generated code in AdderSoapBindingStub.class - In the corresponding method of the Stub class add the following lines of code after the _call.invoke(...) statementMessageContext message = _call.getMessageContext(); //.getRequestMessage(); Iterator it = message.getRequestMessage().getAttachments();while (it.hasNext()) {AttachmentPart part = (AttachmentPart) it.next(); try {System.out.println("File Name : " + part.getDataHandler().getDataSource().getName());InputStream is = part.getDataHandler().getInputStream(); while (is.available() > 0) {System.out.print((char) is.read()); } } catch (Exception ex) {ex.printStackTrace(); }

73. 2010-02-0838REST

74. Each unique URL is a representation of some objectEx : http://www.mycompany.com/india/hyd/employees http://www. mycompany.com/india/hyd/employees/1234HTTP GET Method operates on the resource.Object state is transferred and stored at client.Representation of the resource state in XML, JSON etc.2010-02-0839RESTful web servicesREpresentationalState Transfer

75. Every object has its own unique methodsMethods can be remotely invoked over the InternetA single URI represents the end-point, and that's the only contact with the WebData hidden behind method calls and parametersData is unavailable to Web applicationsRPC vs RESTRPCRESTEvery useful data object has an address

76. Resources themselves are the targets for method calls

77. The list of methods is fixed for all resources2010-02-0841RESTful web services contd…PrinciplesResource identification through URI

78. Uniform interface GET/PUT/POST/DELETESelf-descriptive messages

79. Stateful interactions through hyperlinksBenefitsClient sideEasy to experiment in browserBroad programming language supportChoice of data formatsbookmarkableServer sideUniform Interface

80. Cacheable

81. Scalable

82. Easy failover42ExampleRequestGET/india/hyd/employees/1234 HTTP/1.1Host: mycompany.comAccept: application/xmlResponseHTTP/1.1 200 OKDate: Tue, 09 Feb 2010 11:41:20 GMTServer: Apache/1.3.6Content-Type: application/xml; charset=UTF-8<?xml version="1.0"?><Employees xmlns="…"> <Employee name=“ABC”> … </Employee></Employees>ResourceMethodStatetransferRepresentation2010-02-08

83. 2010-02-0843Developing a RESTful web service using JAX-WSpackage com.sun.jersey.samples.helloworld.resources;import javax.ws.rs.GET;import javax.ws.rs.Produces;import javax.ws.rs.Path;@Path("/employees/{empid}")public class Employee{@GET @Produces("text/xml") public String getEmployee(@PathParam(“empid") String empId) { ... … }}

84. REST Annotations

85. REST Annotations

86. Securing web servicesSSL is not enoughSSL provides point to point securityWS needs end to end securitySSL provides security at transport levelWS needs security at message levelSSL doesn’t support non-repudiationNon-repudiation is critical for business WSWeb service security requirementsAuthentication ( Identity check )Authorization ( Access Control )Confidentiality ( Encryption )Integrity ( Signature Support )Non-repudiation ( Ability to prove that a particular transaction is performed)Accessibility ( Ensuring that the service is not impacted by attacks)2010-02-0846

87. XML digital signature ( IETF and W3C)XML Encryption ( W3C)SAML (Secure Assertion Markup Language) ( OASIS)WS-Security (Web Services Security) (OASIS)WS-SecureConversationWS-FederationWS-PolicyWS-TrustWS-PrivacyXACML (Extensible Access Control Markup Language) (OASIS)2010-02-0847Web service security standards

88. “BPEL is an XML language for defining the composition of web services into new services”BPEL would require that every process Either has a “center” of executionA process is composed of a large set of orchestration definitions interacting with each otherBPEL assumes that business processes can be fully captured in a single definition, including all possible exception pathsNot sure this is the right assumptionBPEL

89. Identify the partners in the processDeclare the Partners in the ProcessDesign the workflow of the processDefine up the workflow processDeclare the Process Using BPEL Activity ConstructsAdd Business Logic Using BPELConstructsBPEL Steps

90. Open source specification project from the Object Management Group (OMG), describing a UML profile and metamodel for the modeling and design of services within a service-oriented architecture.SoaML(SOA Modeling Language)

91. Dealer Network ArchitectureThe dealer network is defined as a community “collaboration” involving three primary roles for participants in this community: the dealer, manufacturer, and shipper. The following diagram illustrates these roles and services in the dealer network architecture. SOAML Example

92. The enterprise service bus (ESB) is a software infrastructure that facilitates application integration. An ESB does not itself implement SOA but provides the features with which SOA can be implemented.ExamplesGlassfish ESB (Sun)Websphere ESB (IBM)Biztalk Server (Microsoft)JBOSS ESBESB

93. InvocationRoutingMediationMessage ProcessingService OrchestrationComplex Event ProcessingManagementCommon ESB Characteristics

94. SOAP - http://www.w3c.org/TR/soapWSDL - http://www.w3c.org/TR/wsdlUDDI - http://www.uddi.xml.orgSAML - http://saml.xml.orgebXML - http://www.ebxml.orgCORBA Vs. Web services - http://www2002.og/CDROM/alternate/395SoaML - http://www.omg.org/spec/SoaMLBPEL - www.oasis-open.org/committees/wsbpel2010-02-0854For more information

95. 2010-02-0855Questions?

96. Thank You2010-02-0856