Recursive pattern using HashMaps

[Anthony Ikeda <an...@proxima-tech.com.au>]

I have a class that operates in the same way a hashmap does and I want to be able to convert it to an org.w3c.dom.Element (then to an org.w3c.dom.Document or DocumentImpl).

The code I'm trying to use recurses onto itself to create a new element each time it comes across a nested HashMap object.
For example:

<%!
  public Element convertHashMap(HashMap hm, Document doc){

    Iterator it = hm.keySet().iterator();

    while(it.hasNext()){
        String key = (String)it.next(); //all hashmap keys are strings
        Element topElement = doc.createElement(key);
        Object obj = hm.get(key);
        if(obj instanceof java.util.HashMap){
            HashMap hm2 = (HashMap) obj;
            Element tempElement = convertHashMap(hm2,doc);

            if(tempElement!=null)
                topElement.appendChild(tempElement);
        }
    }
    return tempElement;
  }
%>


When I try and run this method in a JSP I get:

Error: 500 Location: /Centauri/CommonCockpit/src/com/proxima/centauri/servlets/servicemodel/testPage.jspInternal Servlet Error:java.lang.IllegalStateException: Response has already been committed
 at org.apache.tomcat.core.HttpServletResponseFacade.sendError(HttpServletResponseFacade.java:157)
 at org.apache.jasper.runtime.JspServlet.unknownException(JspServlet.java:299)
 at org.apache.jasper.runtime.JspServlet.service(JspServlet.java:377)
 at com.borland.jbuilder.webserverglue.tomcat.jsp.JspLoaderEcho.service(Unknown Source)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
 at org.apache.tomcat.core.ServletWrapper.handleRequest(ServletWrapper.java:503)
 at org.apache.tomcat.core.ContextManager.service(ContextManager.java:559)
 at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:160)
 at org.apache.tomcat.service.TcpConnectionThread.run(SimpleTcpEndpoint.java:338)
 at java.lang.Thread.run(Thread.java:484)

Does this mean the doc has been closed or something? Is it possible to actually perform such an operation?

Cheers,
Anthony Ikeda