Accessing SOAP server programatically with a client

Question

Hi!
I have found lots of documentation on how to send messages to a SOAP server when the xml is already specified. A lot less is written how this should be done programatically, and I can't find the solution to my problem. (I think doing it programatically is more pretty....)
So, I got my web server up and running (JBoss 4.0.5GA), and the web service is deployed as it should (I've tested it using hard-coded ws request, which succeed).
I also got a bunch of java files generated using wsdl2java, which I am using to create my request. The first thing I want to do is a simple login.
The code (stripped a bit for convenience):
public void run()
               throws AxisFault, InterruptedException {
          // set up some initial stuff
          SOAPFactory factory = new SOAP12Factory();
          Options options = new Options();
          options.setTo(mTargerEPR);
          // log in to the system
          SOAPEnvelope payload = createLoginDocument(factory);
          // set the action to use for this call
          options.setAction("CAI3G#Login");
          // Non-Blocking Invocation
          ServiceClient sender = new ServiceClient();
          sender.setOptions(options);
          process(payload, sender);
private SOAPEnvelope createLoginDocument(SOAPFactory factory) {
          LoginDocument loginDocument = LoginDocument.Factory.newInstance();
          LoginDocument.Login login = loginDocument.addNewLogin();
          login.setUserId("admin");
          login.setPwd("admin");
          return toEnvelope(factory, loginDocument);
private SOAPEnvelope toEnvelope(SOAPFactory factory, XmlObject document) {
          SOAPEnvelope envelope = factory.createSOAPEnvelope();
          // create the header, which must contain sequence id and session id
          factory.createSOAPHeader(envelope);
          if (document != null) {
               // create the body and include the document provided
               SOAPBody body = factory.createSOAPBody(envelope);
               body.addChild(toOM(document));
          return envelope;
private static void process(SOAPEnvelope payload, ServiceClient sender)
               throws AxisFault, InterruptedException {
          Callback callback = new Callback() {
               // currently just print it to test
               public void onComplete(AsyncResult result) {
                    System.out.println(result.getResponseEnvelope());
               public void onError(Exception e) {
                    e.printStackTrace();
           sender.sendReceiveNonBlocking(payload, callback);
          // Wait until the callback receives the response.
          while (!callback.isComplete()) {
               Thread.sleep(1000);
     }The error I receive looks like this:
2007-05-29 15:30:03,644 [INFO] Axis2 Task - I/O exception (org.apache.axis2.AxisFault) caught when processing request: Can not output XML declaration, after other output has already been done.
2007-05-29 15:30:03,644 [INFO] Axis2 Task - Retrying request
2007-05-29 15:30:03,644 [INFO] Axis2 Task - I/O exception (org.apache.axis2.AxisFault) caught when processing request: Can not output XML declaration, after other output has already been done.
2007-05-29 15:30:03,644 [INFO] Axis2 Task - Retrying request
2007-05-29 15:30:03,644 [INFO] Axis2 Task - I/O exception (org.apache.axis2.AxisFault) caught when processing request: Can not output XML declaration, after other output has already been done.
2007-05-29 15:30:03,644 [INFO] Axis2 Task - Retrying request
org.apache.axis2.AxisFault: Can not output XML declaration, after other output has already been done.
     at org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:221)
     at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:452)
     at org.apache.axis2.description.OutInAxisOperationClient.send(OutInAxisOperation.java:330)
     at org.apache.axis2.description.OutInAxisOperationClient$NonBlockingInvocationWorker.run(OutInAxisOperation.java:405)
     at edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:665)
     at edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:690)
     at java.lang.Thread.run(Thread.java:619)
Caused by: javax.xml.stream.XMLStreamException: Can not output XML declaration, after other output has already been done.
     at com.ctc.wstx.sw.BaseStreamWriter.throwOutputError(BaseStreamWriter.java:1473)
     at com.ctc.wstx.sw.BaseStreamWriter.reportNwfStructure(BaseStreamWriter.java:1502)
     at com.ctc.wstx.sw.BaseStreamWriter.doWriteStartDocument(BaseStreamWriter.java:699)
     at com.ctc.wstx.sw.BaseStreamWriter.writeStartDocument(BaseStreamWriter.java:687)
     at org.apache.axiom.soap.impl.llom.SOAPEnvelopeImpl.internalSerialize(SOAPEnvelopeImpl.java:190)
     at org.apache.axiom.om.impl.llom.OMElementImpl.internalSerializeAndConsume(OMElementImpl.java:808)
     at org.apache.axiom.om.impl.llom.OMElementImpl.internalSerialize(OMElementImpl.java:779)
     at org.apache.axiom.om.impl.llom.OMElementImpl.internalSerializeAndConsume(OMElementImpl.java:808)
     at org.apache.axiom.soap.impl.llom.SOAPEnvelopeImpl.serializeInternally(SOAPEnvelopeImpl.java:234)
     at org.apache.axiom.soap.impl.llom.SOAPEnvelopeImpl.internalSerialize(SOAPEnvelopeImpl.java:222)
     at org.apache.axiom.om.impl.llom.OMElementImpl.internalSerializeAndConsume(OMElementImpl.java:808)
     at org.apache.axiom.om.impl.llom.OMNodeImpl.serializeAndConsume(OMNodeImpl.java:418)
     at org.apache.axis2.transport.http.SOAPMessageFormatter.writeTo(SOAPMessageFormatter.java:55)
     ... 19 more
In JBoss, I get this exception:
15:30:04,285 ERROR [[localhost]] Exception Processing ErrorPage[errorCode=500, location=/axis2-web/Error/error500.jsp]
org.apache.jasper.JasperException: getOutputStream() has already been called for this response
Any idea/pointer, someone? All help is greatly appreciated!
Best regards,
Peter

Answer 1

I thought it might be worth to give a printout of the generated xml and the hard-coded, working xml.
The working one:
<env:Envelope
     xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"
     xmlns:xs="http://www.w3.org/1999/XMLSchema"
     xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance"
     xmlns:enc="http://schemas.xmlsoap.org/soap/encoding/"
     env:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
     <env:Header />
     <env:Body>
             <cai3g:Login xmlns:cai3g="http://schemas.ericsson.com/cai3g1.1/">
                  <cai3g:userId>admin</cai3g:userId>
                  <cai3g:pwd>admin</cai3g:pwd>
             </cai3g:Login>
     </env:Body>
</env:Envelope>The one I've generated, when doing a System.out.println() on the variable payload:
<?xml version='1.0' encoding='utf-8'?>
<soapenv:Envelope
     xmlns:xs="http://www.w3.org/1999/XMLSchema"
     xmlns:soapenv="http://www.w3.org/2003/05/soap-envelope"
     xmlns:enc="http://schemas.xmlsoap.org/soap/encoding/"
     xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance">
     <soapenv:Body>
          <Login xmlns="http://schemas.ericsson.com/cai3g1.1/">
               <userId>admin</userId>
               <pwd>admin</pwd>
          </Login>
     </soapenv:Body>
</soapenv:Envelope>