Java Reference
In-Depth Information
payloadsasXML,andisknownasa
dispatch client
.Aswith
Provider
,
Dispatch
offers a
T invoke(T)
method. Dispatch clients call this method to send messages
synchronouslytoproviders,andtoobtainproviderresponsesfromthismethod'sreturn
value.
Note
Dispatch
offers additional invocation methods, such as
Response<T>
invokeAsync(T msg)
for invoking the
Provider
's
invoke()
method asyn-
chronously. This method returns immediately; the result of the
Provider
's
in-
voke()
method is made available in the returned
Response<T>
object at some
point in the future —the
javax.xml.ws.Response
interface extends the
java.util.concurrent.Future<T>
interface, which I discuss in
Chapter 6
.
A dispatch client obtains an object whose class implements
Dispatch<T>
by
invoking one of
Service
's
createDispatch()
methods. For example,
Dis-
patch<T> createDispatch(QName portName, Class<T> type, Ser-
vice.Mode mode)
returns a
Dispatch
instance for communicating with the
web service through the port identified by
portName
, using the specified
Source
,
SOAPMessage
, or
DataSource
counterpart to the actual type argument passed to
Provider<T>
, and via the service mode (message or payload) passed to
mode
.
Afterthe
Dispatch
instancehasbeenobtained,adispatchclientwillcreateanob-
ject conforming to the actual type argument passed to
T
, and pass this instance to the
web service provider in a call to
Dispatch
's
invoke()
method. To understand the
interplaybetweenadispatchclientandaprovider,consideraclientthatinvokes
Dis-
patch<Source>
's
invoke()
method with an XML document made available via
the
Source
argument. The following sequence occurs:
• The provider's JAX-WS runtime dispatches the client request to
Provider-
<Source>
's
invoke()
method.
• The provider transforms the
Source
instance into an appropriate
javax.xml.transform.Result
instance (such as a DOM tree), pro-
cessesthis
Result
instanceinsomemanner,andreturnsa
Source
instance
containing XML content to JAX-WS, which transmits the content to
Dis-
patch
's
invoke()
method.
•
Dispatch
's
invoke()
methodreturnsanother
Source
instancecontaining
the XML content, which the dispatch client transforms into an appropriate
Result
instance for processing.
