Processing web service messages

Use IBM® Integration Bus nodes and services to connect to other web services providers and consumers.

About this task

A web service is a software system designed to support interoperable computer-to-computer interaction over a network. It has an interface described by an XML-based specification; specifically, the Web Service Definition Language, or WSDL.

Web services fulfill a specific task or a set of tasks. A web service is described using a standard, formal XML notation, called its service description, that provides all the details necessary to interact with the service, including message formats (that detail the operations), transport protocols, and location.

The nature of the interface hides the implementation details of the service, so that it can be used independently of the hardware or software platform on which it is implemented. The interface is also independent of the programming language in which it is written. This interface handles web service-based applications as loosely coupled, component-oriented, cross-technology implementations. Web services can be used alone, or with other web services, to carry out a complex aggregation or a business transaction.

The IBM Integration Bus environment provides two different development styles for developing web services:
  • For an assisted development environment to provide web services, where you can focus on implementing service operations instead of directly handling the transport-level interaction, consider using Services. For more information, see Developing integration solutions by using integration services.
  • For more fine-grained control over developing a web service, consider creating your own message flows which use SOAPInput nodes directly. For more information, see Message flows for web services. You might want to do this in the following situations:
    • You are providing a web service over JMS.
    • You want to provide a gateway for multiple services.
    • You want more operational control over how web services are grouped.

To call a web service as part of your message flow, include SOAPRequest nodes in the message flow appropriately. For more information, see Message flows for web services.

For more information about how IBM Integration Bus acts as a web service provider or consumer, and how it complies with external web service standards, see IBM Integration Bus and web services.

Once you have developed an IBM Integration Bus solution, the IBM Integration Bus administrator can apply policies to affect how messages are secured or when messages are retransmitted. The administrator also controls how the listener behaves, and can work with an external listener for HTTP traffic. For more information, read the following topics:
The following topics describe how to work with web services:

IBM Integration Bus supplies a Java™ servlet that you can use in an external Web servlet container such as IBM WebSphere Application Server or Apache Tomcat, to receive HTTP requests from web services client applications. The HTTP proxy servlet is described in HTTP proxy servlet overview.