1 / 22

Web Services

Web Services. Kanda Runapongsa ( krunapon@kku.ac.th ) Dept. of Computer Engineering Khon Kaen University. What are Web Services?. Web services are loosely coupled software components delivered over Internet standard technologies

muncel
Télécharger la présentation

Web Services

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Web Services Kanda Runapongsa (krunapon@kku.ac.th) Dept. of Computer Engineering Khon Kaen University

  2. What are Web Services? • Web services are loosely coupled software components delivered over Internet standard technologies • Facilitate delivering business applications as a service accessible to anyone, anytime, at any location, and using any platform 168493: XML and Web Services (II/2546)

  3. Web Services Characteristics • Based on XML messaging • Data exchanged between the Web service provider and the user are defined in XML • Web services provide a cross-platform integration of business applications over the Internet 168493: XML and Web Services (II/2546)

  4. Web Services Characteristics • To build Web services, developers can use any common programming language, such as Java, C, C++, Perl, Python, C#, and /or Visual Basic • Web services can be used by many types of clients on various types of devices, such as Wireless device, PDA, Desktop, Automobile 168493: XML and Web Services (II/2546)

  5. Web Services Characteristics • Web services vary in functionality from a simple request to a complex business transaction involving multiple resources • All platforms including J2EE, CORBA, and Microsoft .NET provide extensive support for creating and deploying Web services 168493: XML and Web Services (II/2546)

  6. Web Services Characteristics • Web services use industry-standard protocols like HTTP, and they can be easily accessible through corporate firewalls • Web services are dynamically located and invoked from public and private registries based on industry standards such as UDDI and ebXML 168493: XML and Web Services (II/2546)

  7. Web Applications vs. Web Services • Traditionally, Web applications enable interaction between an end user and a Web site • Web Services are service-oriented and enable application-to-application communication over the Internet and easy accessibility to heterogeneous applications and devices 168493: XML and Web Services (II/2546)

  8. Why Use Web Services? • Can be invoked through XML-based RPC mechanisms across firewalls • Provide a cross-platform, cross-language solution based on XML messaging • Facilitate ease of application integration using a light-weight infrastructure without affecting scalability • Enable interoperability among heterogeneous applications 168493: XML and Web Services (II/2546)

  9. Operational Model of Web Services Service Broker Discover Service Register Service Service Requestor Service Provider Invoke Service 168493: XML and Web Services (II/2546)

  10. Operational Model of Web Services • Service provider • Developing and deploying the Web services • Define the services and publishes them with the service broker • Service broker (service registry) • List various service types, descriptions, and locations of the services that help the service requesters find and subscribe to the required services 168493: XML and Web Services (II/2546)

  11. Operational Model of Web Services • Service requestor • Locate the Web service using the service broker • Invoke the required services • Execute the services from the service provider 168493: XML and Web Services (II/2546)

  12. Web Services Communication Models • In Web services architecture, the communication models can be • RPC-based synchronous • Messaging-based synchronous/asynchronous 168493: XML and Web Services (II/2546)

  13. REQUEST Service Requester Service Provider RESPONSE RPC-Based Communication Model • Define a request/response-based synchronous communication • When the client sends a request, the client waits until a response is sent back from the server before continuing any operation 168493: XML and Web Services (II/2546)

  14. RPC-Based Communication Model • Clients invoke the Web services by sending parameter values to the Web service provider • The Web service provider executes the required method and sends back the return values 168493: XML and Web Services (II/2546)

  15. Messaging-based Communication Model • Define a loosely coupled and document-driven communication • The service requestor does not wait for a response MESSAGE Service Requester Service Provider 168493: XML and Web Services (II/2546)

  16. Messaging-based Communication Model • The client sends an entire document rather than sending a set of parameters • The service provider receives the document, processes it, and then may or may not return a message • With a synchronous model, the client can request a service, then wait, and receive the document from the service provider 168493: XML and Web Services (II/2546)

  17. Implementing Web Services • 1. The service provider • Creates the Web service typically as SOAP-based service interfaces • Deploys the service and make them available for invocation over a network • Describes the Web service as a WSDL-based service description 168493: XML and Web Services (II/2546)

  18. Implementing Web Services • 2. The service provider • Registers the WSDL-based service description with a service broker, which is typically a UDDI registry • 3. The UDDI registry • Stores the service description as binding templates and URLs to WSDLs located in the service provider environment 168493: XML and Web Services (II/2546)

  19. Implementing Web Services • 4. The service requestor • Locates the required services by querying the UDDI registry • Obtains the binding information and the URLs to identify the service provider • 5. The service requestor • Invokes the service provider • Retrieves the WSDL Service description for those registered services 168493: XML and Web Services (II/2546)

  20. Implementing Web Services • 6. The service requestor • Communicate with the service provider • Exchange data or messages by invoking the available services in the service container 168493: XML and Web Services (II/2546)

  21. Implementing Web Services 3. Store service description Service Broker 4. Locate services and its binding info 2. Register/Publish Services 5. Invoke & obtain WSDL Service Requestor Service Provider 6. Exchange data using SOAP RPC/Messaging 1. Create Web Service and WSDL 168493: XML and Web Services (II/2546)

  22. Sun released its Java API for Web Services for the developer community as the Java Web Services Developer Pack (JWSDP) It provides a full-fledged solution package for developing and testing Web services using the Java APIs, such as JAXM, JAXP, JAXR, JAXB, JAX-RPC, Java WSDP Register Server, and JSTL Apache released Apache Axis as a tool for creating and testing Web services Building Web Services in the J2EE Environment 168493: XML and Web Services (II/2546)

More Related