Information Technology Reference
In-Depth Information
messages to a service task will be consumers. Services will be assigned to the partici-
pant corresponding to the pool containing each activity, and the associated Service
Contract will hold all service information. Fig. 4 displays some Service and Request
Ports (formerly Points) for the services defined, showing the bidirectional and unidi-
rectional pattern of communication that can be defined.
D2
-
Specify services
. The specification of services corresponds to the definition of
all the information needed, including the associated Service Contract with interfaces,
operations, input and output parameters, among others. The information related to the
in and out messages must be specified, indicating the parameters and data to be
exchanged between the parties. The choreography defined by the Service Contract
must also be specified, based on the interaction between participants. Once all this
information has been considered, the most important parts of the ServiceContract can
be generated and this can then be completed by the Architect or developers, who will
also have to give the implementation details. Fig. 5 presents the ServiceContract
definition and its choreography for the “ReceiveAppointmentRequest” service.
Fig. 5.
ServiceContract and Choreography for the “ReceiveAppointmentRequest” service
D3 - Investigate existing services.
The principal goal of this activity is to reuse the
organization's existing services, as far as possible. To do so, a central Service Cata-
logue is defined, which has to be searched in each service development project. In the
SoaML component diagram an adapter or wrapper has to be defined to relate the
design service to its existing implementation, linking them in activity D4.
D4 - Assign components to services.
The components that will implement the ser-
vices generated must be defined and shown in the components diagram. For each
service, a component with which to implement it has to be defined. SoaML provides
the participant component with which to define the implementation of participants
and services, defining new components to be generated and, if one exists, defining
adapters or wrappers to use it.
