Chapter 6 Introduction to Web ServicesObjectivesWhat is Web services?What is Web services? (continue)What are the difference between website access and Web servicesWhat are the difference between website access and Web services (continue)Slide 7What Web services can do and cannot doSlide 9Identify the key technologies involved in Web servicesIdentify the key technologies involved in Web services (continue)Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Identify who manages the Web services specificationsIdentify who manages the Web services specifications (continue)Slide 22Examine the examples of the Web servicesQuestions and DiscussionHomework for Extra PointsChapter 6Chapter 6Introduction to Web ServicesIntroduction to Web ServicesObjectivesObjectivesBy study of the chapter, you will be able to:By study of the chapter, you will be able to:Describe what is Web servicesDescribe what is Web servicesDescribe what are differences between website Describe what are differences between website access and Web services access and Web services Describe what Web services can do and cannot doDescribe what Web services can do and cannot doIdentify the key components or technologies involved Identify the key components or technologies involved in Web services in Web services Identify who manages the Web services Identify who manages the Web services specificationsspecificationsexamine the examples of the Web servicesexamine the examples of the Web servicesQuestions and DiscussionQuestions and DiscussionHomeworkHomeworkWhat is Web services? What is Web services? A Web service is a software application that can be A Web service is a software application that can be accessed remotely using different XML-based accessed remotely using different XML-based languageslanguagesA Web service normally identified by a URL, just like A Web service normally identified by a URL, just like you access any other website. You can use the you access any other website. You can use the service provided by the website, such as currency service provided by the website, such as currency exchange rate and calculation, weather reports for a exchange rate and calculation, weather reports for a specified city, or language translationspecified city, or language translationThose services are not stored at your computer, but Those services are not stored at your computer, but in the server. You will can those services remotely in the server. You will can those services remotely at your computer to the remote server via the at your computer to the remote server via the InternetInternetWhat is Web services? What is Web services? (continue)(continue)Your request for a Web service will be transmitted by Your request for a Web service will be transmitted by XML and send the request with all parameters to the XML and send the request with all parameters to the Web services serverWeb services serverThen the request will be received, parsed, and Then the request will be received, parsed, and executed by the server. Finally, the result of the executed by the server. Finally, the result of the service as a response, will be sent back to your service as a response, will be sent back to your screen, and extracted by SOAP message parserscreen, and extracted by SOAP message parserDoesn’t matter what operating system and computer Doesn’t matter what operating system and computer language you use, A Web service will recognize your language you use, A Web service will recognize your request, since it follows all of the standards, request, since it follows all of the standards, especially the XML and SOAP appliancesespecially the XML and SOAP appliances Example of a Web serviceExample of a Web service–World LingoWorld Lingo (a free online translator) (a free online translator)What are the difference between What are the difference between website access and Web serviceswebsite access and Web servicesMost websites are designed to provide a Most websites are designed to provide a response to a request from a user; response to a request from a user; furthermore, the user either type in the URL, furthermore, the user either type in the URL, or click on a hyperlink, to create a request. or click on a hyperlink, to create a request. This request then takes the form of a text This request then takes the form of a text document that contains some fairly simple document that contains some fairly simple instructions for the serverinstructions for the serverIn a website access, these instructions are In a website access, these instructions are limited to the name of a document to be limited to the name of a document to be returned or a call to a server-side program returned or a call to a server-side program with a few parameterswith a few parametersWhat are the difference between What are the difference between website access and Web services website access and Web services (continue)(continue)However, in a Web service, the content in a However, in a Web service, the content in a request from a user to the server is sending by request from a user to the server is sending by XML documentXML documentThe document formatted in a special way in The document formatted in a special way in accordance with the rules of the SOAP accordance with the rules of the SOAP specificationspecificationA SOAP message can contain a call to a method A SOAP message can contain a call to a method along with any parameters that might be neededalong with any parameters that might be neededThe complexity of a SAOP message far exceeds The complexity of a SAOP message far exceeds the complexity that is possible using only a Web the complexity that is possible using only a Web browserbrowserWe will discuss SOAP in later chaptersWe will discuss SOAP in later chaptersWhat are the difference between What are the difference between website access and Web services website access and Web services (continue)(continue)In summary, a Web service uses XML In summary, a Web service uses XML specification, but a website uses a text specification, but a website uses a text documentdocumentA Web service follows SOAP specification, but A Web service follows SOAP specification, but a website only follows a web browser’s rules, a website only follows a web browser’s rules, so that its complexity to handle the request is so that its complexity to handle the request is greatly limitedgreatly limitedWhat Web services can do and What Web services can do and cannot