Non-blocking WS call with CXF

问题

I need to call a WS that has very large response times (seconds) - without any polling/callback mechanism implemented on their side.

I think the most effective way of doing this is using non-blocking io and some kind of callback mechanism when the response received. Since we mostly use Spring and CXF I started a proof-of concept project to test my concept and the configuration itself.

Fortunately there is an HttpAsyncClient for cxf and there are good tutorials how to configure it. But at some point I stucked: with sync mode it is ok, but when I want to use the callback, it thorows the following exception:

javax.xml.ws.WebServiceException: Could not find wsdl:binding operation info for web method getDataFromWebServiceAsync.
    at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:126)
    at com.sun.proxy.$Proxy46.getDataFromWebServiceAsync(Unknown Source)

ws interface:

@WebService
public interface SampleWebService {
    public Person getDataFromWebService(@WebParam String id);
    public Future<?> getDataFromWebServiceAsync(@WebParam String id, @WebParam(name = "asyncHandler", targetNamespace = "") AsyncHandler<Person> asyncHandler);
}

client side test (implemented as a TestNG test):

@Test(threadPoolSize = 5, invocationCount = 100)
public void testMultithreadedNonBlockingSampleWs()
        throws InterruptedException, ExecutionException {

    client.getDataFromWebServiceAsync("" + id.getAndIncrement(),
            new AsyncHandler<Person>() {
                @Override
                public void handleResponse(Response<Person> resp) {
                    Person person;
                    try {
                        person = resp.get();
                        log.info(person.getName() + " | " + person.getAge()
                                + " | " + person.getDescription());
                        Assert.assertNotNull(person);
                        Assert.assertNotNull(person.getName());
                    } catch (InterruptedException | ExecutionException e) {
                        log.error("EXCEPTION WHILE PROCESSING RESPONSE CALLBACK");
                        e.printStackTrace();
                    }
                }
            });
}

server-side spring congfiguration:

<jaxws:endpoint id="sampleService"
    implementor="my.sample.SampleWebServiceImpl" address="/SampleWebService" />

client-side spring configuration:

<jaxws:client id="client"
    serviceClass="my.sample.SampleWebService"
    address="http://localhost:8080/sample-ws-cxf/SampleWebService">
    <jaxws:properties>
        <entry key="javax.xml.ws.client.connectionTimeout" value="10" />
        <entry key="javax.xml.ws.client.receiveTimeout" value="11000" />
        <entry key="org.apache.cxf.transport.http.async.usePolicy" value="ALWAYS" />
        <entry key="org.apache.cxf.transport.http.async.ioThreadCount" value="2" /> 
    </jaxws:properties>
</jaxws:client>

From the articles I found it is not clear whether this (non-blocking callback) is really possible or only the polling/callback mechanism should work. Only this article states that: http://czechscala.wordpress.com/2013/05/13/non-blocking-soap-web-services-invocation/

Could anybody provide me clarification at this point? Any way of achieving this? Or any solution to handle long-running WS calls in a reasonable way?

回答1:

If I generate the interfaces out of wsdl using the '-asyncMethods' parameter, everything is fine! The main difference is that it generates a wrapper object around my Person object called GetDataFromWebServiceResponse. Now everything is fine: the server is called through the normal interface (no polling/callback implemented), but on client side the callback method is called upon response.

Working pom.xml particle:

<execution>
    <id>generate-sources</id>
    <phase>generate-sources</phase>
    <configuration>
        <sourceRoot>${full.path.to.generate.classes}</sourceRoot>
        <wsdlOptions>
            <wsdlOption>
                <wsdl>${full.path.to.wsdl}</wsdl>
                <extraargs>
                    <extraarg>-p</extraarg>
                    <extraarg>${package.name}</extraarg>
                    <extraarg>-asyncMethods</extraarg>
                </extraargs>
            </wsdlOption>
        </wsdlOptions>
    </configuration>
</execution>

I would suggest using cxf above 2.7.

Now I'm wondering how could anybody force calling the poll/callback style service methods from client side.... but that would be another story :-)

来源：https://stackoverflow.com/questions/25241712/non-blocking-ws-call-with-cxf

标签

Spring

web-services

cxf

nonblocking