What is Web Services?

Web Service is a new Web application. Program Branch. They are self-contained, self-described, and modular applications that can be released, located, and called through the Web. Web services can execute any function from simple requests to complex business processing. After deployment, other Web service applications can discover and call the services deployed by the application.
Web Service is an application that uses standard Internet protocols, such as Hypertext Transfer Protocol (HTTP) and XML, to visually display functions on the Internet and on the enterprise intranet. Web services can be considered as Web component programming.
Web services are built on common protocols, such as HTTP, soap, XML, WSDL, and UDDI. These protocols involve operating systems, object models, and Programming Language There is no tendency to choose, so there will be a strong vitality. But there are some differences between. NET and J2EE in Web Service programming .. Net web services can be written in C #, VB, JScript, and other languages, and some windows resources can be used. J2EE Web services generally use Java and J2EE resources, such as bean, EJB, and so on. They also have their own characteristics in the programming environment, syntax structure, and management configuration. The inet Web Service uses Java to implement the Web Service APIs provided in the. NET class library. It can port web services developed by users using. Net to Java that is not related to the platform. Because it is Java, Java resources can also be used.
What role does web services play?
These trends mean that more intelligent Processing, operations, and summary of content become very important. Let's look at the four trends predicted from the Web Services perspective:
◆ More dynamic content: A web service must be able to merge content from multiple sources, including stocks, weather, news, and other content in the traditional environment, such as inventory level, purchase orders or directory information are all from the back-end system.
◆ Cheaper bandwidth: Web services can distribute various types of content (such as audio and video streams)
◆ Cheaper storage: Web services must be able to process a large amount of data intelligently, which means that the database, LDAP directory, buffering, and Server Load balancer technologies must be used to maintain scalability.
◆ Universal computing is more important: Web Services does not require customers to use traditional Windows browsers of a certain version. They must support various devices, platforms, browser types, and content types.
To achieve this goal, Web Services uses two technologies:
◆ XML is a great way to transmit structured data on the Web. Web services must operate data in a reliable and automatic manner. HTML does not meet the requirements, XML allows web services to process data conveniently, and its content and representation separation is ideal.
◆ Soap uses XML messages to call remote methods, so that web services can interact with remote machines through the post and get methods of the HTTP protocol. In addition, soap is more robust, flexible, and easy to use.
Other technologies such as UDDI and WSDL are closely integrated with XML and soap for service discovery.
So what is the Web service platform? The most basic platform is XML and HTTP. HTTP is a widely used protocol on the Internet. XML is a metalanguage. You can use it to write specific languages to describe the interaction between customers and services or between components and complex services. After the web server, messages in XML format are converted into requests in middleware, and the returned results are also converted into XML format.
It is necessary to add some services while maintaining simplicity and universality to build the Web into a more powerful platform. The fully functional web services platform can be considered as XML + HTTP + soap + WSDL + UDDI. At a higher level, some unwidely accepted technologies such as XAML, XLANG, XKMS, and XFS may be added.