I'm in the process of trying to convert the Enterprise java example to a servlet. The login works fine, but when I try to execute a query I get the followingn error:

Failed to execute query succesfully, error message was:
; nested exception is:
 java.io.IOException: No serializer found for class com.sforce.soap.enterprise._SessionHeader in registry org.apache.axis.encoding.TypeMappingImpl@96ad7c

My guess is that I'm not persisting or passing the login session header to the query request. Can someone tell me how to do this in a servlet or JSP? I can't find examples of this anywhere. Here is my servlet:

package sforcetest3;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.io.BufferedReader;
//import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.rmi.RemoteException;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Vector;

import javax.xml.rpc.ServiceException;

import com.sforce.soap.enterprise.DescribeGlobalResult;
import com.sforce.soap.enterprise.DescribeSObjectResult;
import com.sforce.soap.enterprise.Field;
import com.sforce.soap.enterprise.FieldType;
import com.sforce.soap.enterprise.GetDeletedResult;
import com.sforce.soap.enterprise.GetUpdatedResult;
import com.sforce.soap.enterprise.GetUserInfoResult;
import com.sforce.soap.enterprise.ID;
import com.sforce.soap.enterprise.LoginResult;
import com.sforce.soap.enterprise.PicklistEntry;
import com.sforce.soap.enterprise.QueryResult;
import com.sforce.soap.enterprise.ResetPasswordResult;
import com.sforce.soap.enterprise.SaveResult;
import com.sforce.soap.enterprise.SearchRecord;
import com.sforce.soap.enterprise.SearchResult;
import com.sforce.soap.enterprise.SetPasswordResult;
import com.sforce.soap.enterprise.SforceServiceLocator;
import com.sforce.soap.enterprise.SoapBindingStub;
import com.sforce.soap.enterprise._QueryOptions;
import com.sforce.soap.enterprise._SessionHeader;
//import com.sforce.soap.enterprise.fault.LoginFault;
import com.sforce.soap.enterprise.sobject.Account;
import com.sforce.soap.enterprise.sobject.Contact;
import com.sforce.soap.enterprise.sobject.Lead;
import com.sforce.soap.enterprise.sobject.SObject;
import com.sforce.soap.enterprise.sobject.Task;
import com.sforce.soap.enterprise.sobject.User;
import com.sforce.soap.enterprise.fault.*;

public class Servlet1
    extends HttpServlet {
  private static final String CONTENT_TYPE = "text/html";
  private SoapBindingStub binding;
  private LoginResult loginResult = null;
  private String un = "XXX";
  private String pw = "XXX";
  private boolean loggedIn = false;
  private GetUserInfoResult userInfo = null;
  private ID[] accounts = null;
  private ID[] contacts = null;
  private ID[] tasks = null;

  //Initialize global variables
  public void init() throws ServletException {
  }

  //Process the HTTP Get request
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws
      ServletException, IOException {

    response.setContentType(CONTENT_TYPE);
    PrintWriter out = response.getWriter();

    if (request.getQueryString() == null) { // login if

      out.println("attribute names: " + request.getQueryString());

      out.println("Creating the binding to the web service...<P>");

      /*
       * There are 2 ways to get the binding, one by passing a url to
       * the getSoap() method of the SforceServiceLocator,
       * the other by not passing a url.  In the second case the binding
       * will use the url contained in the wsdl file when the proxy was
       * generated.
       */
      try {
        binding = (SoapBindingStub)new SforceServiceLocator().getSoap();
      }
      catch (ServiceException ex) {
        out.println(
            "ERROR: createing binding to soap service, error was: \n"
            + ex.getMessage());
        out.print("Hit return to continue...<P>");
      }

      // Time out after a minute
      binding.setTimeout(60000);

      //Attempt the login giving the user feedback
      out.println("LOGGING IN NOW....<P>");
      try {
        loginResult = binding.login(un, pw);
      }
      catch (LoginFault lf) {
        out.println(lf.getExceptionMessage());
        //lf.printStackTrace();
      }
      catch (UnexpectedErrorFault uef) {
        out.println(uef.getExceptionMessage());
        uef.printStackTrace();
      }
      catch (RemoteException re) {
        out.println(re.getMessage());
        re.printStackTrace();
      }

      out.println("The session id is: " + loginResult.getSessionId() + "<P>");
      out.println("The new server url is: " + loginResult.getServerUrl() +
                  "<P>");

      //set the session header for subsequent call authentication
      try {
        binding = (SoapBindingStub)new SforceServiceLocator().getSoap(new URL(
            loginResult.getServerUrl()));
      }
      catch (ServiceException jre) {
        System.out.println(
            "ERROR: creating binding to soap service, error was: \n" +
            jre.getMessage());
      }
      catch (MalformedURLException e) {
        e.printStackTrace();
      }

      //Create a new session header object and set the session id to that returned by the login
      _SessionHeader sh = new _SessionHeader();
      sh.setSessionId(loginResult.getSessionId());
      binding.setHeader("SforceService", "SessionHeader", sh);

      out.println("<a href=/sForceWeb/servlet1?doQuery=1>query</a>");

    } // login if

    //out.println(request.getParameter("doQuery"));

    if (request.getParameter("doQuery") != null) {
      out.println("doQuery");

      QueryResult qr = null;
      _QueryOptions qo = new _QueryOptions();
      qo.setBatchSize(new Integer(3));
      binding.setHeader("SoapService", "QueryOptions", qo);

      try {
        qr = binding.query(
            "select id, Website, Name from Account where Name = 'Golden Straw'");
        if (qr.getSize() != 0) {
          Account account = ( (Account) qr.getRecords()[0]);
         out.println("Retrieved " + new Integer(qr.getSize()).toString() +
                             " account(s) using Name = 'Golden Straw', ID = "
                             + account.getId().getValue()
                             + ", website = "
                             + account.getWebsite());
        }

        qr = binding.query("select FirstName, LastName, Id from Contact");

        boolean bContinue = true;
        int loopCount = 0;
        while (bContinue) {
          out.println("Results set " + new Integer(loopCount++).toString() +
                             " - ");
          //process the query results
          for (int i = 0; i < qr.getRecords().length; i++) {
            Contact con = (Contact) qr.getRecords()[i];
            String fName = con.getFirstName();
            String lName = con.getLastName();
            if (fName == null) {
              out.println("Contact " + (i + 1) + ": " + lName);
            }
            else {
              out.println("Contact " + (i + 1) + ": " + fName + " " +
                                 lName);
            }
          }
          //handle the loop + 1 problem by checking to see if the most recent queryResult
          if (qr.isDone()) {
            bContinue = false;
          }
          else {
            qr = binding.queryMore(qr.getQueryLocator());
          }
        }
        out.println("\nQuery succesfully executed.");
        //getUserInput("\nHit return to continue...");
      }

      catch (UnexpectedErrorFault uef) {
        System.out.println(uef.getExceptionMessage());
      }
      catch (Exception ex) {
        System.out.println(
            "\nFailed to execute query succesfully, error message was: \n"
            + ex.getMessage());
      }

    }

  }

  //Process the HTTP Post request
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws
      ServletException, IOException {
    doGet(request, response);
  }

  //Clean up resources
  public void destroy() {
  }
}