Introduction to Web Service

WEB Sevice Platform

Three basic elements of Web Service: SOAP, WSDL, UDDI

What is soap:
Xml+http Basic Web Service Platform
SOAP Simple Object Access Protocol, a format for sending messages, platform-independent, language-independent, XML-based

What is WSDL:
WSDL is an XML-based language for describing Web service and how to access Web service
WSDL Network Service Description language, written using XML

What is UDDI:
UDDI is a directory service
UDDI refers to a common description, discovery, and consolidation, a directory for storing information about Web services, a directory of network Service interfaces described by WSDL, and fine soap for communication

Simply put, WebService is some of the site to open some services, it can be your own development of service, that is, some methods, through the URL, specify a method name, make a request, the site of this service (method), received your request, according to the parameters passed over, do some processing, The processed results are then returned in XML to you, and your program parses the XML data and then displays it or does other things.
For example: Many large sites provide WebService with weather forecasts, and as soon as you make a request, it returns the weather forecast data, and then you display the results in your own program.

what is a Web ServiceWe have at least two kinds of answers to this question. On the surface, a Web service is an application that exposes an API that can be called through the web. This means that you can programmatically invoke the application via the Web. We call the application calling this Web service a customer. For example, you want to create a Web service that is useful for returning the current weather conditions. Then you can create an ASP page that accepts the ZIP code as a query string, and then returns a comma-separated string containing the current temperature and weather. To invoke this ASP page, the client needs to send the following HTTP get returned data should be: 21 This ASP page should be counted as a Web service. It exposes an API that can be called through the Web because it is based on an HTTP GET request. Of course, there is more to the WEB service. The following is a more precise explanation of Web services: A Web service is a new platform for building interoperable, distributed applications. As a Windows programmer, you may have built a component-based distributed application with COM or DCOM. COM is a very good component technology, but we can easily cite the case that COM does not meet the requirements. The Web service platform is a set of standards that defines how applications can interoperate on the web. You can write Web services on any platform you like, in any language you like, as long as we can query and access them through the Web service standard.