Chapter 40. Developing Asynchronous Applications
40.1. Types of Asynchronous Invocation
- Polling approach — To invoke the remote operation using the polling approach, you call a method that has no output parameters, but returns a
Responseobject (which inherits from the
javax.util.concurrency.Futureinterface) can be polled to check whether or not a response message has arrived.
- Callback approach — To invoke the remote operation using the callback approach, you call a method that takes a reference to a callback object (of
javax.xml.ws.AsyncHandlertype) as one of its parameters. When the response message arrives at the client, the runtime calls back on the
AsyncHandlerobject, and gives it the contents of the response message.