HTTP is most often used as a Web-Service transport protocol. However, it is not able to meet the asynchronous communication requirements.
Web-Service on XMPP transport is capable of asynchronous communication in which a client doesn't need to wait for a response from a service; instead, the service sends the response to the client when the process is completed. Spring-WS 2.0 includes XMPP (Jabber) support in which a Web-Service can communicate over the XMPP protocol. In this recipe, setting up a Spring-WS on XMPP transport is presented. Since there is no external HTTP server, a test class is used to load the application context.
In this recipe, the project's name is LiveRestaurant_R-1.7, which has the following Maven dependencies:
spring-ws-core-2.0.1.RELEASE.jarspring-ws-support-2.0.1.RELEASE.jarspring-test-3.0.5.RELEASE.jarjunit-4.7.jarxmlunit-1.1.jarsmack-3.1.0.jar
Create an endpoint (
SamplePlayLoadEndPoint).Configure connection to the XMPP server in the application context (
applicationContext.xml).Configure the message receiver in the application context.
Run the following command:
mvn clean packageThe following is the response received:
<placeOrderRequest xmlns="..."><id>9999</id></placeOrderRequest> ... for request ...<placeOrderRequest xmlns="...."><id>9999</id></placeOrderReque t>...
In the application context, the messageFactory bean is responsible for creating the incoming and outgoing SOAP messages. The messageReceiver bean acts as a server, using a connection (to XMPP server:google talk), and listens to the host on a specific service with a username and password.
<bean id="messageFactory" class="org.springframework.ws.soap.saaj.SaajSoapMessageFactory"/>
<bean id="connection" class="org.springframework.ws.transport.xmpp.support.XmppConnectionFactoryBean">
<property name="host" value="talk.google.com"/>
<property name="username" value="[email protected]"/>
<property name="password" value="yourPassword"/>
<property name="serviceName" value="gmail.com"/>
</bean>
<bean id="messagingReceiver" class="org.springframework.ws.transport.xmpp.XmppMessageReceiver">
<property name="messageFactory" ref="messageFactory"/>
<property name="connection" ref="connection"/>
<property name="messageReceiver" ref="messageDispatcher"/>
</bean>Once the message is sent by the client, it will be forwarded to the endpoint (SamplePlayLoadEndPoint that is configured within messageDispatcher) by the message dispatcher and the response will be returned to the client:
<bean id="messageDispatcher"
class="org.springframework.ws.soap.server.SoapMessageDispatcher">
<property name="endpointMappings">
<bean class="org.springframework.ws.server.endpoint.mapping.PayloadRootQNameEndpointMapping">
<property name="defaultEndpoint"> <bean class="com.packtpub.liverestaurant.service.endpoint.SamplePlayLoadEndPoint"/>
</property> </bean>
</property>
</bean>
Webservicetemplate
is used here as a client; it will be discussed in the next chapter.
SamplePlayLoadEndPoint
just receives a request and returns a response:
public class SamplePlayLoadEndPoint implements PayloadEndpoint {
static Logger logger = Logger.getLogger(SamplePlayLoadEndPoint.class);
public Source invoke(Source request) throws Exception {
return request;
}A test class is included in the project to load the application context, set up the XMPP Web-Service server, and test the Web-Service.
The Creating Web-Service client on XMPP transport recipe discussed in Chapter 2, Building Clients for SOAP Web-Services.