The web service broker uses web protocols and XML. We can use this pattern to expose and broker the services. Assume a circumstance, where multiple organizations are lined up in order to request info from a number of service providers. A broker provides the central medium which makes the transfer of information happen.
It is a general gateway or an address in order for the client apps to be able to access a large, diverse variety of services. These services might need a broker in order to make an interaction with either only a single server app or multiple server apps. The broker performs certain tasks. It is responsible for receiving SOAP requests from the client apps in XML format along with authenticating the request and checking for the authorization. You can also use it to generate calls to multiple server apps, which depends on nature of the request.
UML class diagram for Web Service Broker
Let’s see the following UML class diagram for the Web Service Broker.
This composition of the calls includes, sequencing the calls in order to the server app and creating a list of input arguments forever server app. You can also use the broker for collecting data from all the legacy server apps. And then transform it into XML format output. It requires XML format output to fulfill the specification in XSD of this web service. This XML contains SOAP header info and it has the capability of becoming the response.
The client app which is invoking requests receives this response. The broker can come in handy when we need to publish all of the offered services. There are certain benefits of using web service broker pattern. This design pattern exposes the current services to the web. This design pattern comes in handy in situations where the developer needs to expose the services as the web services.