SOAP based interoperation of heterogeneous systems

Csúcs Gergely <wizard@avalon.aut.bme.hu>

BME AAIT

Marossy Kálmán <coloman@avalon.aut.bme.hu>

BME AAIT

Charaf Hassan Phd <hassan@avalon.aut.bme.hu>

BME AAIT

Nowadays the component-based way of software development represents the trend. The components being used for assembling software can originate from several sources. The common factor is that software components don’t come out of nowhere, somebody has to develop them.

Generic components (such as GUI elements) are usually brought with the chosen development environment. Other typical high level services (e.g. security: authentication or even transaction management) are also easy to acquire.

Our job is to develop the rest. Unfortunately it’s not sure that we are able to do that: for example we are short of time. We should always keep the phrase in mind: there’s nothing new under the sun. It’s quite unlikely that every required service is a brand new one, no one has ever developed anything similar. As life is a continuous progression, the operation supported by our new software was working in the past some way, and perhaps was working with the assist of an information system. It can be a good idea to reuse parts of that information system, but sometimes it is not too simple because that software was built on a previous technology. The typical way to interoperate with these software parts is to build a wrapper around them, so they became components. Such a component is an entity, which interactively communicates with its environment with the protocol we need, the protocol provided by the wrapper.

A good protocol that we may need is a protocol based on XML, a data description language specified by the W3C. The interactive communication may be done with the SOAP protocol, a protocol specified for interoperating communication.

In this article we want to show how to make an interoperating component from parts of a legacy system with the help of SOAP.