Architecture of connector for web services

To illustrate the architecture of the components at a high level, this section describes two data flows. Figure 2 illustrates the two scenarios. These two scenarios are described below.

Figure 2. 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).

Copyright IBM Corp. 2003