Architecture of connector for web services
To illustrate the architecture of the components at a
high level, this section describes two data flows. Figure 3 illustrates the two scenarios. These two scenarios
are described below.
Figure 3. Flow of a web services message
Request processing illustrates the sequence
of events that occurs when a collaboration makes a service call
request to the connector to invoke a web service. In this scenario,
the collaboration plays the role of a client, sending a request
to a server.
- A
- The collaboration sends a service call request to the connector,
which calls the SOAP data handler to convert the business object
to a SOAP request message.
- B
- The connector invokes the web service WS2 by sending the SOAP
message. If the destination is an external web service, the connector
sends the SOAP message to a gateway. The gateway sends the SOAP
message to the endpoint corresponding to the destination web service.
This invokes the web service.
- C
- The invoked web service receives the SOAP request message
and performs the requested processing.
- D
- The invoked web service sends a SOAP response (or fault) message.
If the web service is external to the enterprise, a gateway receives
and routes the SOAP response message.
- E
- The SOAP response (or fault) message is routed back to the
connector, which calls the data handler to convert it to a response
or fault business object.
- F
- The connector returns the SOAP response or fault business
object to the collaboration.
Event processing illustrates the sequence
of events that occurs when a collaboration is called as a web service.
In this scenario, the collaboration, which is exposed as a web service,
plays the role of the server, accepting a request from a client,
external or internal, and responding as required.
- 1
- The client web service (WS1) sends a SOAP request message
to the destination specified in the WSDL document generated for
the collaboration.
- 2
- If the client web service is external, the gateway receives
and routes the message to the connector.
- 3
- The connector sends the SOAP message to the SOAP data handler
to convert the SOAP message to a business object. The connector
invokes the collaboration exposed as a web service.
- 4
- The collaboration returns a SOAP Response (or Fault) business
object.
- 5
- The connector calls the SOAP data handler to convert the SOAP
Response (or Fault) business object to a SOAP response message.
The connector returns the response to the gateway.
- 6
- If the client web service is external, the gateway routes
the SOAP response message to the client web service (WS1).
