Web Service | Part 1

Web Service | Part 1

Web Service

As defined by the World Wide Web Consortium (W3C) Web Services (web service) is a software system designed to support interoperability between different computers on the same network key feature of a Web Service is to offer a ‘ software interface’ (described in an automatically processable format such as, for example, the Web Services Description Language) using the other systems which may interact with the Web Service itself by activating the steps in the interface by means of special “messages” included in an “envelope” (the most famous is SOAP): these messages are usually transported via the HTTP protocol and formatted according to the XML standard.

Thanks to the use of XML standards, through an architecture based on Web Service (Service Oriented Architecture – SOA) software applications written in different programming languages and deployed on different hardware platforms can be used through the interfaces that they “expose” publicly and through the use of functions that are able to make (the “products” to make available) for the exchange of information and the conduct of complex operations (such as , the execution of business processes that involve multiple areas of the same company) and on corporate networks, as well as on the Internet: the possibility of interoperability between different programming languages (e.g., between Java and Python) and operating systems (such as Windows and Linux) is made possible by the use of standard “open”.

The consortium OASIS (Organization for the Advancement of Structured Information Standards) and W3C are primarily responsible for the architecture and standardization of Web services, to improve interoperability between different implementations of Web Services WS-I organization is also developing a series of “profiles” to better define the standards involved.

Protocol stacks of Web Service

The protocol stack of Web services is the set of network protocols used to identify, locate, implement and to interact with each Web Service, is mainly composed of four areas:

  • Transport Service: Responsible for transporting messages between applications on the network, including protocols such as HTTP, SMTP, FTP, XMPP, and the recent Blocks Extensible Exchange Protocol (BEEP).
  • XML Messaging: all data exchanged is formatted with a “tag” XML so that they can be used at both ends of the connections, the message can be encoded in accordance with the SOAP standard, as well as use JAX-RPC, XML-RPC or REST.
  • Description of service: the public interface of a Web Service is described by WSDL (Web Services Description Language) an XML-based language used to create “documents” describing how to interface and use of the Web Service.
  • List of services: the centralization of the description and the location of the Web Service in a “register” Joint allows you to search and quickly find the Web Service available on the web, is currently used for this purpose the protocol UDDI.

Additional standard protocols used are:

  • WS-Security: the protocol Web Services Security protocol was adopted as an OASIS Standard, this standard allows user authentication and confidentiality of messages exchanged with the interface of Web Service
  • WS-Reliability: This is based on SOAP specifications and accepted as an OASIS Standard that satisfy the request message “reliable” (reliable), required for some of the critical applications that use Web services (such as, for example, monetary transactions or E-commerce applications).

Advantages of Web Services

  • Allow interoperability between different software applications on different hardware platforms
  • Using standard protocols and “open” protocols and data format and, where possible, in text format, which makes them easier to understand and use by developers
  • Through the use of HTTP to transport messages the Web Service does not require, normally, that changes are made to the security rules used as a filter on the firewall
  • Can be easily used in combination with each other (regardless of who supplies them and where they are available) to form services “integrated” and complex.
  • Allow reuse of infrastructure and applications already developed and are (relatively) independent of any changes to these

Web Services — More Benefits

  • Web services provide interoperability between various software running on various platforms.
  • Web services use open protocols and standards.
  • The protocols and data formats are text wherever possible, thus facilitating the understanding of how global trade.
  • Based on HTTP protocol, Web services can work through many firewalls without requiring changes to filtering rules.
  • Development tools based on these standards, allow the automatic creation of programs using existing Web services.