Provider
.
Applications that use the JAX-WS RI can implement this interface instead of
Provider
to implement asynchronous web services (AWS.) AWS enables
applications to perform operations with long latency without blocking a thread,
and thus particularly suitable for highly scalable service implementation,
at the expesnce of implementation complexity.
Programming Model
Whenever a new reuqest arrives, the JAX-WS RI invokes the invoke(T, com.sun.xml.ws.api.server.AsyncProviderCallback<T>, jakarta.xml.ws.WebServiceContext)
method
to notify the application. Normally, the application then schedules an execution
of this request, and exit from this method immediately (the point of AWS is not
to use this calling thread for request processing.)
Unlike the synchronous version, which requires the response to be given as the return value,
with AWS the JAX-WS RI will keep the connection with client open, until the application
eventually notifies the JAX-WS RI via AsyncProviderCallback
. When that
happens that causes the JAX-WS RI to send back a response to the client.
The following code shows a very simple AWS example:
@WebService class MyAsyncEchoService implements AsyncProvider<Source> { private static finalExecutor
exec = ...; public void invoke( final Source request, final AsyncProviderCallback<Source> callback, final WebServiceContext context) { exec.execute(newRunnable
() { public void run() { Thread.sleep(1000); // kill time. callback.send(request); // just echo back } }); } }
Please also check the Provider
and its programming model for general
provider programming model.
WebServiceContext
In synchronous web services, the injected WebServiceContext
instance uses
the calling Thread
to determine which request it should return information about.
This no longer works with AWS, as you may need to call WebServiceContext
much later, possibly from entirely different thread.
For this reason, AsyncProvider
passes in WebServiceContext
as
a parameter. This object remains usable until you invoke AsyncProviderCallback
,
and it can be invoked from any thread, even concurrently. AWS must not use the injected
WebServiceContext
, as its behavior is undefined.
- Since:
- 2.1
- Author:
- Jitendra Kotamraju, Kohsuke Kawaguchi
- See Also:
-
Provider
-
Method Summary
Modifier and TypeMethodDescriptionvoid
invoke
(T request, AsyncProviderCallback<T> callback, jakarta.xml.ws.WebServiceContext context) Schedules an execution of a request.
-
Method Details
-
invoke
void invoke(@NotNull T request, @NotNull AsyncProviderCallback<T> callback, @NotNull jakarta.xml.ws.WebServiceContext context) Schedules an execution of a request.- Parameters:
request
- Represents the request message or payload.callback
- Application must notify this callback interface when the processing of a request is complete.context
- The web service context instance that can be used to retrieve context information about the given request.
-