The following sections describe how to create a buffered Web Service:
When a buffered operation is invoked by a client, the method operation goes on a JMS queue and WebLogic Server deals with it asynchronously. As with Web Service reliable messaging, if WebLogic Server goes down while the method invocation is still in the queue, it will be dealt with as soon as WebLogic Server is restarted. When a client invokes the buffered Web Service, the client does not wait for a response from the invoke, and the execution of the client can continue.
The following procedure describes how to create a buffered Web Service and a client Web Service that invokes an operation of the buffered Web Service. The procedure shows how to create the JWS files that implement the two Web Services from scratch. If you want to update existing JWS files, use this procedure as a guide. The procedure also shows how to configure the WebLogic Server instance that hosts the buffered Web Service.
Note: | Unless you are also using the asynchronous request-response feature, you do not need to invoke a buffered Web Service from another Web Service, you can also invoke it from a stand-alone Java application. |
It is assumed that you have set up an Ant-based development environment and that you have a working build.xml
file to which you can add targets for running the jwsc
Ant task and deploying the generated buffered Web Service. It is further assumed that you have a similar setup for the WebLogic Server instance that hosts the client Web Service that invokes the buffered Web Service. For more information, see in Getting Started With WebLogic Web Services Using JAX-RPC:
Use your favorite IDE or text editor. See Programming Guidelines for the Buffered JWS File.
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<jwsc
See
“Running the jwsc WebLogic Web Services Ant Task” in Getting Started With WebLogic Web Services Using JAX-RPC for general information about using the
jwsc Ant task.
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prompt> ant build-clientService deploy-clientService
For more information about deployment, see See
“Deploying and Undeploying WebLogic Web Services” in Getting Started With WebLogic Web Services Using JAX-RPC.
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prompt> ant build-clientService deploy-clientService
For more information about deployment, see See
“Deploying and Undeploying WebLogic Web Services” in Getting Started With WebLogic Web Services Using JAX-RPC.
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Configuring the WebLogic Server instance on which the buffered Web Service is deployed involves configuring JMS resources, such as JMS servers and modules, that are used internally by the Web Services runtime.
You can configure these resources manually or you can use the Configuration Wizard to extend the WebLogic Server domain using a Web Services-specific extension template. Using the Configuration Wizard greatly simplifies the required configuration steps; for details, see “Configuring Your Domain For Web Services Features” in Getting Started With WebLogic Web Services Using JAX-RPC.
Note: | Alternatively, you can use WLST to configure the resources. For information about using WLST to extend the domain, see “Configuring Existing Domains” in WebLogic Scripting Tool. |
If you prefer to configure the resources manually, perform the following steps.
See
“Invoking the Administration Console” in Getting Started With WebLogic Web Services Using JAX-RPC.
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Create a JMS Server. If a JMS server already exists, you can use it if you do not want to create a new one.
See
“Create JMS servers” in the Administration Console Online Help.
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Create a JMS module, and then define a JMS queue in the module. If a JMS module already exists, you can use it if you do not want to create a new one. Target the JMS queue to the JMS server you created in the preceding step. Be sure you specify that this JMS queue is local, typically by setting the local JNDI name. See
“Create JMS system modules” and
“Create queues in a system module” in the Administration Console Online Help.
If you want the buffered Web Service to use the default Web Services queue, set the JNDI name of the JMS queue to
weblogic.wsee.DefaultCallbackQueue . Otherwise, if you use a different JNDI name, be sure to use the @BufferQueue annotation in the JWS file to specify this JNDI name to the reliable Web Service. See Programming Guidelines for the Buffered JWS File.
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Review
“Tuning Heavily Loaded Systems to Improve Web Service Performance” in WebLogic Server Performance and Tuning.
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The following example shows a simple JWS file that implements a buffered Web Service; see the explanation after the example for coding guidelines that correspond to the Java code in bold.
package examples.webservices.buffered;
import javax.jws.WebMethod;
import javax.jws.WebService;import javax.jws.Oneway;
import weblogic.jws.WLHttpTransport;import weblogic.jws.MessageBuffer;
import weblogic.jws.BufferQueue;
@WebService(name="BufferedPortType",
serviceName="BufferedService",
targetNamespace="http://example.org")
@WLHttpTransport(contextPath="buffered",
serviceUri="BufferedService",
portName="BufferedPort")
// Annotation to specify a specific JMS queue rather than the default
@BufferQueue(name="my.jms.queue")
/**
* Simple buffered Web Service.
*/
public class BufferedImpl {
@WebMethod()@MessageBuffer(retryCount=10, retryDelay="10 seconds")
@Oneway()
public void sayHelloNoReturn(String message) {
System.out.println("sayHelloNoReturn: " + message);
}
}
Follow these guidelines when programming the JWS file that implements a buffered Web Service. Code snippets of the guidelines are shown in bold in the preceding example.
import javax.jws.Oneway;
import weblogic.jws.MessageBuffer;
import weblogic.jws.BufferQueue;
See the following bullets for guidelines on which JWS annotations are required.
@BufferQueue
JWS annotation to specify the JNDI name of the JMS queue used internally by WebLogic Server when it processes a buffered invoke; for example:
@BufferQueue(name="my.jms.queue")
If you do not specify this JWS annotation, then WebLogic Server uses the default Web Services JMS queue (weblogic.wsee.DefaultQueue
).
You must create both the default JMS queue and any queues specified with this annotation before you can successfully invoke a buffered operation. See Configuring the Host WebLogic Server Instance for the Buffered Web Service for details.
@MessageBuffer
JWS annotation to specify the operations of the Web Service that are buffered. The annotation has two optional attributes: retryCount
: The number of times WebLogic Server should attempt to deliver the message from the JMS queue to the Web Service implementation (default 3).retryDelay
: The amount of time that the server should wait in between retries (default 5 minutes).@MessageBuffer(retryCount=10, retryDelay="10 seconds")
You can use this annotation at the class-level to specify that all operations are buffered, or at the method-level to choose which operations are buffered.
@Oneway
annotation to specify that the method is one-way. This means that the method cannot return a value, but rather, must explicitly return void
. For example:@Oneway()
public void sayHelloNoReturn(String message) {
Conversely, if the method is not annotated with the @Oneway
annotation, then you must invoke it using the asynchronous request-response feature. If you are unsure how the operation is going to be invoked, consider creating two flavors of the operation: synchronous and asynchronous.
See Invoking a Web Service Using Asynchronous Request-Response, and Using the Asynchronous Features Together.
You can invoke a buffered Web Service from both a stand-alone Java application (if not using asynchronous request-response) and from another Web Service. Unlike other WebLogic Web Services asynchronous features, however, you do not use the @ServiceClient
JWS annotation in the client Web Service, but rather, you invoke the service as you would any other. For details, see
“Invoking a Web Service from Another Web Service” in Getting Started With WebLogic Web Services Using JAX-RPC.
The following sample JWS file shows how to invoke the sayHelloNoReturn
operation of the BufferedService
Web Service:
package examples.webservices.buffered;
import java.rmi.RemoteException;
import javax.xml.rpc.ServiceException;
import javax.jws.WebService;
import javax.jws.WebMethod;
import weblogic.jws.WLHttpTransport;
import examples.webservices.buffered.BufferedPortType;
import examples.webservices.buffered.BufferedService_Impl;
import examples.webservices.buffered.BufferedService;
@WebService(name="BufferedClientPortType",
serviceName="BufferedClientService",
targetNamespace="http://examples.org")
@WLHttpTransport(contextPath="bufferedClient",
serviceUri="BufferedClientService",
portName="BufferedClientPort")
public class BufferedClientImpl {
@WebMethod()
public String callBufferedService(String input, String serviceUrl)
throws RemoteException {
try {
BufferedService service = new BufferedService_Impl(serviceUrl + "?WSDL");
BufferedPortType port = service.getBufferedPort();
// Invoke the sayHelloNoReturn() operation of BufferedService
port.sayHelloNoReturn(input);
return "Invoke went okay!";
} catch (ServiceException se) {
System.out.println("ServiceExcpetion thrown");
throw new RuntimeException(se);
}
}
}
To update a build.xml
file to generate the JWS file that invokes a buffered Web Service operation, add taskdefs
and a build-clientService
targets that look something like the following example. See the description after the example for details.
<taskdef name="jwsc"
classname="weblogic.wsee.tools.anttasks.JwscTask" />
<target name="build-clientService">
<jwsc
enableAsyncService="true"
srcdir="src"
destdir="${clientService-ear-dir}" >
<jws file="examples/webservices/buffered/BufferedClientImpl.java">
<clientgen
wsdl="http://${wls.hostname}:${wls.port}/buffered/BufferedService?WSDL"
packageName="examples.webservices.buffered"/>
</jws>
</jwsc>
</target>
Use the taskdef
Ant task to define the full classname of the jwsc
Ant tasks.
Update the jwsc
Ant task that compiles the client Web Service to include a <clientgen>
child element of the <jws>
element so as to generate and compile the JAX-RPC stubs for the deployed BufferedService
Web Service. The jwsc
Ant task automatically packages them in the generated WAR file so that the client Web Service can immediately access the stubs. You do this because the BufferedClientImpl
JWS file imports and uses one of the generated classes.