Advice on choosing best approach for xml over http

[cf0051]

Hi,

I need to build a client that exchanges xml messages directly over http to a server process. The remoting api options I have considered for this are:

• Commons HttpClient
• Apache XML-RPC

I am looking for a remoting option that has nice spring integration. Can anyone suggest alternatives?

I intend using xmlbeans or castor to provide schema to object mapping. What other options are there?

Thanks in advance,

Colin

[c.petz@efkon.com]

http://xfire.codehaus.org/Castor

[mlythgoe]

I've used HttpClient a lot and its a very good tool for initiating http communication with remote clients.

If you have a system that just listens and responds to http calls then a servlet that reads the request input stream and puts any result into the servlet response works very well.

I've used this very successfully for an XML messaging system.

[David Winterfeldt]

I made an HttpClient template that makes using HttpClient a little easier. It converts HttpException to a runtime exception so you don't have to catch errors if you don't want to and the template reduces code a little. It also makes setting up authentication a little easier (beans have no param constructors).

Below are a couple of simple examples and there is more info if you follow the links.

HttpClientTemplate

<bean id="httpClient" class="org.springbyexample.httpclient.HttpClientTemplate">
    <property name="defaultUri">
        <value><![CDATA[http://localhost:8093/test]]></value>
    </property>
</bean>

The built in callbacks are for String, InputStream, and a byte array (below String callback).

template.executeGetMethod(new ResponseStringCallback() {
    public void doWithResponse(String response) throws IOException {
        ...
        
        logger.debug("HTTP Get string response. '{}'", response);
    }
});

HttpClientOxmTemplate can also marshall and unmarshall responses using Spring Web Service's OXM Framework for marshalling and unmarshalling.

<bean id="jaxbMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
    <property name="contextPath" value="org.springbyexample.schema.beans"/>
</bean>
    
<bean id="httpClient" class="org.springbyexample.httpclient.HttpClientOxmTemplate">
    <property name="defaultUri">
        <value><![CDATA[http://localhost:8093/test]]></value>
    </property>
    <property name="marshaller" ref="jaxbMarshaller" />
    <property name="unmarshaller" ref="jaxbMarshaller" />
</bean>

template.executePostMethod(persons, new ResponseCallback<Persons>() {
    public void doWithResponse(Persons persons) throws IOException {
        ...
        
        Person result = persons.getPerson().get(0);
        
        ...

        logger.debug("id={}  firstName={}  lastName={}", 
                     new Object[] { result.getId(), 
                                    result.getFirstName(), 
                                    result.getLastName()});
    }
});