Using the MDW RPC Web Service Adapter Activity

Note: This implementor is used to consume RPC-style web services that use a specific WSDL.
For a general-purpose adapter which can consume services using other WSDL's, refer to the Document Web Service Adapter activity.

The class com.centurylink.mdw.workflow.activity.MdwRcpWebServiceAdapter implements an adapter that can be used to invoke standard MDW web services, which has a single port named invokeWebService which takes two arguments: the first is a service name (which is passed to the listener of the receiving end as meta data and is not typically used), and the other is an XML request data in Java String format. The return value is an XML response data in string format as well:

     String invokeWebService(String service, String request)
             throws AdapterException;

Important note: with the new (poolable) implementor, you should not use the retry loop (a link to itself with the label ERROR:RETRY) for the old implementor.

Attributes

• WSDL: This is used to specify the WSDL location. It can take either the standard URL form with HTTP protocol, or a property defined in the MDW or application config file using the standard MDW binding expressions syntax: #{props['my.wsdl.url']}.
• Service Name: Specifies the service name. The value will be passed to the receiving MDW application's listener to its event handlers as a meta data field. This is not typically used, so unless requested by the receiving application specifically, you can specify any value.
• Request Variable: The name of the variable that holds the string XML data of the request.
• Response Variable: The name of the variable that holds the string XML data of the response.
• Log req/resp: A boolean attribute indicating whether the request/response of the external system should be logged in the database (table DOCUMENT for MDW 5.* and ADAPTER_INSTANCE for MDW 4.*).
• Request XSD: A URL indicating the location of XSD for the request. This is for documentation purpose only and has no runtime effect.
• Response XSD: A URL indicating the location of XSD for the response. This is for documentation purpose only and has no runtime effect.

The following additional attributes are supported by the new implementor only:

• Max tries: the maximum number of tries (original and retries) when there is a connection failure (when ConnectionException is thrown). If it is not specified, the default value is 1, namely does not retry.
• Retry interval: the number of seconds to wait for the next retry attempt. If the value is not specified, the default is 120 seconds.

Extending the (Poolable) Implementor

Refer to Using Adapter Activities for documentation on extending poolable implementor in general.

The following lists some potential needs of customization and how they can be achieved:

• Converting responses received normally but indicating error conditions to retriable or non-retriable errors: this can be achieved by overridding the invoke method to throw ConnectionException or AdapterException accordingly.
• Obtaining request data from a place other than a variable configured in the designer: this can be achieved by overriding the getRequestData method.
• Saving the response to a place other than a variable configured through the designer, and/or performing other post processing business logic: this can be achieved by overriding onSuccess .
• Performing custom retry logic and other business logic in case of failure: you can override onFailure.

Extending the Old Implementor

• invoke
• openConnection
• closeConnection