Web Service

Definitions

Webservice is a process and set of protocols to find and connect a system with software that diekspose as services via the web. Web Services can be anything from movie reviews, information exchange, the name and content cd music service to the hotel and flight bookings. Webservice technical infrastructure to ensure that the services of the vendor-vendor different.
Web Service fully web-based standards and xml. Web Service can help:
1. Mediator in the integration platform throughout the execution of a virtual machine.
2. Integration between the Web and OO middleware.
3. Integration of work flow, isolated and sevice-service (Web Services Flow Language - WSFL).
4. Exchange of data on the application of different (X-Schema, XSLT + +)
5. (The future: the standardization of information between the context of web services and client - horizontal integration services).

The main players and standards
Microsoft:. NET SUN: Open Net Environment (ONE) IBM: Web Service Conceptual Architecture (WSCA) W3C: Web Service Workshop Oracle: Web Service Broker Hewlett-Packard: Web Service Platform
1. The ability of the application, function or operation of the exposure to other programs through the open standard, and interoperable.
2. "Payloads" is defined as XML.
3. "Transports" via http or other open Internet protocol.
4. Data accessible from various programming languages, hardware platform or operating system. 5. Middleware from the Internet.

Working Mechanism
Before entering the working mechanisms that occur in the Web Service, will be discussed first-kompenen components that have an important role in the Web Service components can be seen on the standards the web service itself, where the standards of web service is as follows: WSDL Web Services Description Language description http://www.w3.org/TR/wsdl-description from the web service UDDI Universal Discovery, Description & Integration http://www.uddi.org/specification.html Registry on the description of the services SOAP Simple Object Access Protocol http://www.w3.org/TR/SOAP/ transport protocol for communication between the web service Standards other WSRP, WSIA, WSXL ... ....
In addition to the standard-standard Web Service, there is also Sections Web Service (Web Service Dumpstack) heard that task, the task will occur in the process of running a web service, where the task-the task, among others: Wire protocols, Description, Discovery. Sections of the Web Service.
* Wire Rules major protocols: provides a standard, flexible communication channel additional Rules: provide a standard, wire-level representation of data that flexible Advantages: interoperability at the lowest level
* Rules main description: provides standard way to explaining what and how a web service that must be done with flexible. Advantages: interoperability.
* main Discovery Rules: provide a standard, to find the point where the web service in place and how to find additional information about what the web service with flexible Advantages: interoperability, integration of dynamic.
The ability to attribute metadata services registered in UDDI, and then run-quei queries based on metadata that mediates the absolute goal of the UDDI second time in the design and pengekskusian time.
UDDI (Universal Description, Discovery and Integration) has the following tasks: Programmatic description of the business and sevice that supported the Programmatic description of the web service specifications and programming model schema.
Stages of the development of the Web Service itself is: Discover - browse the UDDI registry for Web Service to the existing integration. Transform-create or create the Web Service from the project-the project. Build artifacts that are as SOAP and HTTP service. Develop - Build an example application to enter the client application to make Web service Publish - publish / upload the Web Service in the UDDI registry business.

The advantage of the Web Service
1. The use of open formats for all platforms.
2. Easy in and easy to understand debug.
3. Support a stable interface.
4. Using standards "to open the service once and have multiple users.
5. Easy to mediate messages and processes to add value.
6. Routing and delivery.
7. Security.
8. management and monitoring.
9. schema design and service.
10. Acceleration.
11. easy to develop with additional semantic transport.
12. Open, standards-based text.
13. Achieving a modular.
14. Not expensive to implement (relative).
15. Reduce the cost of enterprise application integration.
16. Implementation of the incremental.
XML allows software developers to expose valuable resources in the form of interoperability which has high, where the resources are all types of applications or storage data used by the organization. XML Web services architecture defines a standard mechanism to provide resources through the delivery of XML messages. To access the resources only with XML transmision messages through a standard protocol such as TCP, HTTP, or SMTP. The word "Web Service" (in short "service") refers to the code of the XML interface to be a source of power, where the bias so difficult to access.
This architecture allows for consumers to support integrated with the XML Web Service application. However, to meet this, consumers should determine the appropriate XML interface along with the message that the message diverse and have the details right. XML scheme can fill needs because this allows developers to explaining the structure of XML messages. XML own scheme, however, can not announce additional details concerning the communication with the Web Service.
Definition of the scheme to tell the XML messages that can be used but not how the messages relate to one another. For example, if there is an XML element named Add the name and other AddResponse, this is likely the second name is related but can not indicate its scheme. Therefore, in addition to know the messages, consumers should also know the possible exchange of messages that are supported by the Web Service (example:., If you send a message Add, you get a message back form AddResponse).
Can exchange messages intended as an exchange operation. Operations conducted by consumers on the most important point interaction service. Each time you use a Web Service, will be conducted inspection operations that supported the list to get all the processes that are available.
1. This is normal for developers to group operations to be connected to the interface-interface. Consumers need to know of these affect the way they create the code. This is important for developers, developers working with Web Service on the scope of object-oriented interface because XML can become a map interface programmatis (or abstract classes) in the language options selected.
2. Consumers also need to know what the communication protocol used for sending messages to the service, along the specific mechanisms involved when using the protocol defined as the use of the command, the header-header, an error code. Packing (binding) specify concrete details of what happened on the cable (wire) with how to use interface with specific communication protocol. Binding also affect message-peasn way in the abstract enkodisasi specify on the wire with the style of service (vs. document. RPC) mechanism and enkodisasi (vs. literal. Terenkodisasi).
3. Service can support binding on the double-binding interface that is determined, but each must be binding dapta accessible at the address identified by a unique URI, is also intended as the end point of the Web Service.
4. Consumers should find out all details outlined before they can interact using the Web Service.
After discussion about the Web Services discussed the many people, this is a sign that the concept of openness among the applications received by both. Everyone is aware of the importance of interoperability between different applications across platforms. This triggered and encouraged by various forms of new business models that start applied in the business world. ECommerce or ebusiness is possible that the occurrence of many transactions between the parties without the restrictions are by geography and limit the use of the platform used by the perpetrators of the business to develop a market that was never possible.
However, realize the ideals - ideals is a long road with many challenges that must be faced. Or the reform era of openness in the IT world it is also not easy. The concept of web services can be successfully and run well when it required were met. One of the implementation of web services is interoperability or abbreviated interop, namely, the activation process of doing a function or calling a method (method call) in the remote or with ordinary term known as Remote Procedure Call (RPC). Interop become a complex and challenging because many parties will interact each other, and will each berinteroperasi parties must meet various agreements. The main problem in interoperability is about:
Transport protocol used to send messages to each other.
Mechanism to send a message containing various parameters to enable a remote procedure call. And receive a response from a program that is activated. Interpret each message received.
Indeed, the efforts - the efforts made to create an interop has been a reliable and continuously carried out by various vendors. Technology - technology such as the Distributed Component Object Model (DCOM) from Microsoft, CORBA, Internet Inter-ORB Protocol (IIOP) from the Object Management Group and many others are, for example. However, none of the various initiatives and technology that can be easily accepted by the developers to build applications - the other berinteroperasi application. Challenges and things - things such as that mentioned above is too difficult to be implemented, and the more difficult when the technology, the technology was in the same or try to integrate technology originating from different platforms.