4-12 Programming Advanced Features of JAX-RPC Web Services for Oracle WebLogic Server
These files are described in detail in the sections that follow.
4.8.1 ConversationService.java File
The example ConversationService.java file is shown in Example 4–1
. The example includes extensive comments that describe its function.
Example 4–1 ConversationService.java File
package conv; import javax.jws.WebMethod;
import javax.jws.WebService; import javax.jws.Oneway;
import weblogic.jws.Conversation; import weblogic.jws.Callback;
import weblogic.jws.CallbackService; import java.io.Serializable;
Demonstrates use of the Conversation annotation to manage the lifetime of the service
and provide data persistence and message correlation. Remember that multiple clients might invoke a web service simultaneously. When
the web service stores data relevant to the client or calls additional services
in order to process a clients request, the service must be able to process returned
data from the external services in the context of the specific client it relates
to. This is all automatic when conversations are used. Remember that not all clients are capable of accepting callbacks.
Specifically, clients operating from behind firewalls may not be able to receive asynchronous
callbacks. You may wish to provide a synchronous interface, like this one, for such clients. If a client can accept callbacks, it must send a callback
endpoint refrence as part of any start conversation method invocation.
To see the behavior in the Test View, invoke startRequest and then getRequestStatus
several times quickly. WebServiceserviceName = ConversationService, portName = conversation,
targetNamespace = http:www.openuri.org public class ConversationService implements Serializable {
Callback public CallbackInterface callback;
private boolean useCallbacks; private int num;
Starts the conversation ConversationConversation.Phase.START
Creating Conversational Web Services 4-13
WebMethod public void startRequestboolean useCallbacks {
this.useCallbacks = useCallbacks; }
WebMethod ConversationConversation.Phase.CONTINUE
public String getRequestStatus { num++;
if num == 1 return This is the first time you call getRequestStatus method.;
if num == 2 useCallbacks { callback.onResultReadyfinished;
return This is the second time you call getRequestStatus method, the conversation has been terminated automtically when the onResultReady callback
method is invoked.; } else
return You have called getRequestStatus method + num + times; }
Used to tell Conversation.jws that the current conversation is no longer needed.
WebMethod ConversationConversation.Phase.FINISH
public void terminateRequest { }
CallbackServiceserviceName = ConversationCallbackService public interface CallbackInterface {
Callback to invoke on the client when the external service returns its result. Will only be called it the client can
accept callbacks and told us where to send them. p
If this callback is used, it implicitly terminates the conversation with no action required on the part of the
client. WebMethod
Oneway ConversationConversation.Phase.FINISH
public void onResultReadyString result; }
}
4.8.2 Service.cs File
