Soap & attachments: encoded or literal??

[Julien Martin]

Hello,
I would like for a ws client to retrieve an image from a ws endpoint. I am totally confused as to how to what encoding style to choose as well as how to implement it.

Here is the code for the client:

  package pack;
 

import java.io.*;
import java.net.*;
import java.util.Enumeration;
import java.util.StringTokenizer;
import javax.activation.DataHandler;
 
import javax.servlet.*;
import javax.servlet.http.*;
import javax.xml.rpc.ServiceException;
import javax.xml.rpc.Stub;
import javax.xml.rpc.server.ServiceLifecycle;
import javax.xml.soap.MessageFactory;
import javax.xml.soap.MimeHeaders;
import javax.xml.soap.SOAPException;
import javax.xml.soap.SOAPMessage;
 
/**
 *
 * @author julien
 * @version
 */
public class ServletFetchesAttachment extends HttpServlet {
    
    
    
    /** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
  
        System.out.println("processRequest");
        
        response.setContentType("image/gif");
        
        PrintWriter out = response.getWriter();
        try { // This code block invokes the retrieveAttachment operation on web service
           DataHandler dh =  getProvidesAttachmentSEIPort().retrieveAttachment();
           //More to go here once I have sorted the encoding problem
        } catch(java.rmi.RemoteException ex) {
            ex.printStackTrace();
        } catch(Exception ex) {
            ex.printStackTrace();
        }
        
        
        out.close();
    }
    
    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }
    
    /** Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }
    
    /** Returns a short description of the servlet.
     */
    public String getServletInfo() {
        return "Short description";
    }
    // </editor-fold>
    
    private pack.ProvidesAttachment getProvidesAttachment() {
        pack.ProvidesAttachment providesAttachment = null;
        try {
            javax.naming.InitialContext ic = new javax.naming.InitialContext();
            providesAttachment = (pack.ProvidesAttachment) ic.lookup("java:comp/env/service/ProvidesAttachment");
        } catch(javax.naming.NamingException ex) {
            ex.printStackTrace();
        }
        return providesAttachment;
    }
    
    private pack.ProvidesAttachmentSEI getProvidesAttachmentSEIPort() {
        pack.ProvidesAttachmentSEI providesAttachmentSEIPort = null;
        try {
            providesAttachmentSEIPort = getProvidesAttachment().getProvidesAttachmentSEIPort();
        } catch(javax.xml.rpc.ServiceException ex) {
            ex.printStackTrace();
            
        }
        return providesAttachmentSEIPort;
    }
    
    
}
  

Here is the code for the endpoint:

  package pack;
 
import java.net.MalformedURLException;
import java.net.URL;
import javax.activation.DataHandler;
import javax.xml.rpc.ServiceException;
import javax.xml.rpc.handler.soap.SOAPMessageContext;
import javax.xml.rpc.server.ServiceLifecycle;
import javax.xml.soap.AttachmentPart;
import javax.xml.soap.SOAPMessage;
 

/**
 * This is the implementation bean class for the ProvidesAttachment web service.
 * Created May 23, 2006 3:40:25 PM
 * @author julien
 */
public class ProvidesAttachmentImpl implements ProvidesAttachmentSEI{
    
    
    // Enter web service operations here. (Popup menu: Web Service->Add Operation)
    /**
     * Web service operation
     */
    public DataHandler retrieveAttachment() throws java.rmi.RemoteException {
        URL url=null;
        DataHandler dataHandler=null;
        try {
            url = new URL("file:///home//julien//tests//logo.gif");
            dataHandler = new DataHandler(url);
                   
        } catch (MalformedURLException ex) {
            ex.printStackTrace();
        }
        return dataHandler;
    }
 
    
}
  

If I choose documentliteral it will not compile and give me the following error message:
**************
Attachment types are not supported in literal mode - Type: "javax.activation.DataHandler"
**************

If I choose nothing (which defaults to encoded in Netbeans) It does compile but when I test the operation, I get this from JBOss 4.0.4:

23:10:14,411 ERROR [SOAPFaultExceptionHelper] SOAP request exception
javax.xml.rpc.JAXRPCException: Cannot create or send response message
        at org.jboss.ws.server.ServiceEndpoint.postProcessResponse(ServiceEndpoint.java:311)
        at org.jboss.ws.server.ServiceEndpoint.handleRequest(ServiceEndpoint.java:236)
        at org.jboss.ws.server.ServiceEndpointServlet.doPost(ServiceEndpointServlet.java:120)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
        at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
        at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
        at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
        at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
        at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
        at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
        at java.lang.Thread.run(Thread.java:595)
Caused by: javax.xml.rpc.JAXRPCException: Cannot obtain serializer factory for: [xmlType={http://java.sun.com/jax-rpc-ri/internal}datahandler,javaType=class javax.activation.DataHandler]
        at org.jboss.ws.soap.SOAPContentElement.getSerializerFactory(SOAPContentElement.java:419)
        at org.jboss.ws.soap.SOAPContentElement.getXMLFragment(SOAPContentElement.java:156)
        at org.jboss.ws.soap.SOAPContentElement.expandToDOM(SOAPContentElement.java:844)
        at org.jboss.ws.soap.SOAPContentElement.getChildNodes(SOAPContentElement.java:761)
        at org.jboss.util.xml.DOMWriter.printInternal(DOMWriter.java:211)
        at org.jboss.util.xml.DOMWriter.printInternal(DOMWriter.java:270)
        at org.jboss.util.xml.DOMWriter.printInternal(DOMWriter.java:270)
        at org.jboss.util.xml.DOMWriter.printInternal(DOMWriter.java:270)
        at org.jboss.util.xml.DOMWriter.print(DOMWriter.java:186)
        at org.jboss.util.xml.DOMWriter.printNode(DOMWriter.java:135)
        at org.jboss.ws.server.ServiceEndpoint.postProcessResponse(ServiceEndpoint.java:305)
        ... 22 more
23:10:14,426 ERROR [CallImpl] Call invocation failed
javax.xml.rpc.soap.SOAPFaultException: javax.xml.rpc.JAXRPCException: Cannot create or send response message
        at org.jboss.ws.jaxrpc.SOAPFaultExceptionHelper.getSOAPFaultException(SOAPFaultExceptionHelper.java:100)
        at org.jboss.ws.binding.soap.SOAPBindingProvider.unbindResponseMessage(SOAPBindingProvider.java:505)
        at org.jboss.ws.jaxrpc.CallImpl.invokeInternal(CallImpl.java:704)
        at org.jboss.ws.jaxrpc.CallImpl.invoke(CallImpl.java:398)
        at org.jboss.ws.jaxrpc.CallProxy.invoke(CallProxy.java:164)
        at $Proxy64.retrieveAttachment(Unknown Source)
        at pack.ServletFetchesAttachment.processRequest(ServletFetchesAttachment.java:43)
        at pack.ServletFetchesAttachment.doGet(ServletFetchesAttachment.java:63)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
        at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
        at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
        at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
        at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
        at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
        at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
        at java.lang.Thread.run(Thread.java:595)
23:10:14,437 ERROR [STDERR] java.rmi.RemoteException: Call invocation failed with code [Client] because of: javax.xml.rpc.JAXRPCException: Cannot create or send response message; nested exception is:
        javax.xml.rpc.soap.SOAPFaultException: javax.xml.rpc.JAXRPCException: Cannot create or send response message
23:10:14,438 ERROR [STDERR]     at org.jboss.ws.jaxrpc.CallImpl.invokeInternal(CallImpl.java:715)
23:10:14,438 ERROR [STDERR]     at org.jboss.ws.jaxrpc.CallImpl.invoke(CallImpl.java:398)
23:10:14,438 ERROR [STDERR]     at org.jboss.ws.jaxrpc.CallProxy.invoke(CallProxy.java:164)
23:10:14,438 ERROR [STDERR]     at $Proxy64.retrieveAttachment(Unknown Source)
23:10:14,439 ERROR [STDERR]     at pack.ServletFetchesAttachment.processRequest(ServletFetchesAttachment.java:43)
23:10:14,439 ERROR [STDERR]     at pack.ServletFetchesAttachment.doGet(ServletFetchesAttachment.java:63)
23:10:14,439 ERROR [STDERR]     at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
23:10:14,439 ERROR [STDERR]     at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
23:10:14,440 ERROR [STDERR]     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
23:10:14,440 ERROR [STDERR]     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
23:10:14,440 ERROR [STDERR]     at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
23:10:14,440 ERROR [STDERR]     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
23:10:14,441 ERROR [STDERR]     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
23:10:14,441 ERROR [STDERR]     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
23:10:14,441 ERROR [STDERR]     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
23:10:14,441 ERROR [STDERR]     at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
23:10:14,441 ERROR [STDERR]     at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
23:10:14,441 ERROR [STDERR]     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
23:10:14,442 ERROR [STDERR]     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
23:10:14,442 ERROR [STDERR]     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
23:10:14,442 ERROR [STDERR]     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
23:10:14,442 ERROR [STDERR]     at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
23:10:14,442 ERROR [STDERR]     at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
23:10:14,443 ERROR [STDERR]     at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
23:10:14,443 ERROR [STDERR]     at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
23:10:14,443 ERROR [STDERR]     at java.lang.Thread.run(Thread.java:595)
23:10:14,443 ERROR [STDERR] Caused by: javax.xml.rpc.soap.SOAPFaultException: javax.xml.rpc.JAXRPCException: Cannot create or send response message
23:10:14,443 ERROR [STDERR]     at org.jboss.ws.jaxrpc.SOAPFaultExceptionHelper.getSOAPFaultException(SOAPFaultExceptionHelper.java:100)
23:10:14,443 ERROR [STDERR]     at org.jboss.ws.binding.soap.SOAPBindingProvider.unbindResponseMessage(SOAPBindingProvider.java:505)
23:10:14,449 ERROR [STDERR]     at org.jboss.ws.jaxrpc.CallImpl.invokeInternal(CallImpl.java:704)
23:10:14,449 ERROR [STDERR]     ... 25 more
                                                                            

I use Netbeans 5.0 and JBoss 4.0.4.

Can anyone help?

Julien.

[Jesus Angeles]

Hi Julien, can you post the wsdl and the service endpoint interface?
[ May 27, 2006: Message edited by: Jesus Angeles ]

[Julien Martin]

Yep,

   <definitions name='ProvidesAttachment' targetNamespace='urn :-P	 rovidesAttachment/wsdl' xmlns='http://schemas.xmlsoap.org/wsdl/' xmlns:ns2='http://java.sun.com/jax-rpc-ri/internal' xmlns:soap='http://schemas.xmlsoap.org/wsdl/soap/' xmlns:tns='urn :-P	 rovidesAttachment/wsdl' xmlns:xsd='http://www.w3.org/2001/XMLSchema'>
 <types>
  <schema targetNamespace='http://java.sun.com/jax-rpc-ri/internal' xmlns='http://www.w3.org/2001/XMLSchema' xmlns:soap11-enc='http://schemas.xmlsoap.org/soap/encoding/' xmlns:tns='http://java.sun.com/jax-rpc-ri/internal' xmlns:wsdl='http://schemas.xmlsoap.org/wsdl/' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'>
   <import namespace='http://schemas.xmlsoap.org/soap/encoding/'/>
   <simpleType name='datahandler'>
    <restriction base='base64Binary'/>
   </simpleType>
  </schema>
 </types>
 
 <message name='ProvidesAttachmentSEI_retrieveAttachmentResponse'>
  <part name='result' type='ns2 :mrgreen: atahandler'/>
 </message>
 <message name='ProvidesAttachmentSEI_retrieveAttachment'></message>
 <portType name='ProvidesAttachmentSEI'>
  <operation name='retrieveAttachment'>
   <input message='tns :-P	 rovidesAttachmentSEI_retrieveAttachment'/>
   <output message='tns :-P	 rovidesAttachmentSEI_retrieveAttachmentResponse'/>
  </operation>
 
 </portType>
 <binding name='ProvidesAttachmentSEIBinding' type='tns :-P	 rovidesAttachmentSEI'>
  <soap:binding style='rpc' transport='http://schemas.xmlsoap.org/soap/http'/>
  <operation name='retrieveAttachment'>
   <soap :-o	 peration soapAction=''/>
   <input>
    <soap:body encodingStyle='http://schemas.xmlsoap.org/soap/encoding/' namespace='urn :-P	 rovidesAttachment/wsdl' use='encoded'/>
   </input>
   <output>
 
    <soap:body encodingStyle='http://schemas.xmlsoap.org/soap/encoding/' namespace='urn :-P	 rovidesAttachment/wsdl' use='encoded'/>
   </output>
  </operation>
 </binding>
 <service name='ProvidesAttachment'>
  <port binding='tns :-P	 rovidesAttachmentSEIBinding' name='ProvidesAttachmentSEIPort'>
   <soap:address location='http://ordinateur:8080/WebAppProvidesAttachment/ProvidesAttachment'/>
  </port>
 </service>
 
</definitions> 

[Nikhil Goel]

Julein ,

Have a look https://jax-rpc.dev.java.net/whitepaper/1.1.2/attachments-howto.html

This is exactly what you are looking for .

Hope it helps.

-nikhil

[Julien Martin]

Hello,

Thanks for the tip. I had a look at the article and here is what I tried to do:

I use a handler in order to attach the image. Whether I attach the attachment from within the service implementation or a handler is the same. Here is my handleResponse method:

     public boolean handleResponse(MessageContext context) {
        
        try{
            SOAPMessageContext smc = (SOAPMessageContext) context;
            SOAPMessage msg = smc.getMessage();
            
            URL url = new URL ("file:///home//julien//tests//logo.gif");
            //DataHandler dataHandler = new DataHandler(url);
            Image image = Toolkit.getDefaultToolkit().createImage(url);
            AttachmentPart apart = msg.createAttachmentPart(image, "image/jpeg");
            
            apart.setContentId("logo_id");
            msg.addAttachmentPart(apart);
 
          
        } catch(Exception e){
            e.printStackTrace();
        }
        return true;
    }
   

Then I try to recover the attachment in the client using pretty much the same way as in the article:

   package pack;
 

import com.sun.xml.rpc.client.StubPropertyConstants;
import java.awt.Image;
import java.io.*;
import java.util.Collection;
 
import javax.servlet.*;
import javax.servlet.http.*;
import javax.xml.rpc.Stub;
import javax.xml.soap.AttachmentPart;
 
public class ServletFetchesAttachment extends HttpServlet {
    
    Collection c;
    
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        System.out.println("processRequest");
        
        PrintWriter out = response.getWriter();
        try {
            
            getProvidesAttachmentSEIPort();
            
            while (c.iterator().hasNext()){
                AttachmentPart atpart = (AttachmentPart) c.iterator().next();
                Image image = (Image) atpart.getContent();
            }
        }  catch(Exception ex) {
            ex.printStackTrace();
        }
        out.close();
    }
    
    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }
    
    /** Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }
    
    /** Returns a short description of the servlet.
     */
    public String getServletInfo() {
        return "Short description";
    }
    // </editor-fold>
    
    private pack.ProvidesAttachment getProvidesAttachment() {
        pack.ProvidesAttachment providesAttachment = null;
        try {
            javax.naming.InitialContext ic = new javax.naming.InitialContext();
            providesAttachment = (pack.ProvidesAttachment) ic.lookup("java:comp/env/service/ProvidesAttachment");
        } catch(javax.naming.NamingException ex) {
            ex.printStackTrace();
        }
        return providesAttachment;
    }
    
    private pack.ProvidesAttachmentSEI getProvidesAttachmentSEIPort() {
        System.out.println("getprovidesattachment");
        pack.ProvidesAttachmentSEI providesAttachmentSEIPort = null;
        try {
            Stub stub;
            providesAttachmentSEIPort = getProvidesAttachment().getProvidesAttachmentSEIPort();
            stub = (Stub)providesAttachmentSEIPort;
            c = (Collection)stub._getProperty(StubPropertyConstants.GET_ATTACHMENT_PROPERTY);
            System.out.println("c " + c);
            providesAttachmentSEIPort= (pack.ProvidesAttachmentSEI)stub;
        } catch(javax.xml.rpc.ServiceException ex) {
            ex.printStackTrace();
            
        }
        return providesAttachmentSEIPort;
    }
   
} 

This always yields a nullpointerexception on the collection object.

Can anyone tell me why??

Thanks in advance,

Julien.