Problem with attachment

[GANDHIRAJAN,AYYAPPAN (HP-India,ex2)]

Hi folks,

I have been facing a problem while using soap RPC attachment. Let me
summarize as follows:

1) Create a header
2) Create a body that contains information about an operation. The operation
or method takes javax.activation.DataHandler as an input
3) Create envelope by combining header and body
4) Create a document from the envelope [Later, I will sign this document and
send the signed XML for invoking secured webservices]

I am able to succeed until step3. While I try to create the document object
at step 4, I am getting DataHandler serializer error. The error description
is as follows:

Exception in thread "main" java.lang.NullPointerException
        at
org.apache.axis.encoding.ser.JAFDataHandlerSerializer.serialize(JAFDa
taHandlerSerializer.java:96)
        at
org.apache.axis.encoding.SerializationContextImpl.serializeActual(Ser
ializationContextImpl.java:1247)
        at
org.apache.axis.encoding.SerializationContextImpl.serialize(Serializa
tionContextImpl.java:787)
        at org.apache.axis.message.RPCParam.serialize(RPCParam.java:225)
        at tests.java.com.hp.mesac.security.client.Test.serialize(Unknown
Source
)
        at
tests.java.com.hp.mesac.security.client.Test.getEnvelopeAsDocument(Un
known Source)
        at tests.java.com.hp.mesac.security.client.Test.main(Unknown Source)



The java source code is also given below. can some one help how I can
resolve it?

Thanks in advance.

Regards,
Ayyappan Gandhirajan

----------------------------------------------------------------------------
-------------------------------------------------------------

public class Test1{

    private static String SOAPSECNS =
"http://schemas.xmlsoap.org/soap/security/2000-12";;
    private static String SOAPSECprefix = "SOAP-SEC";

        public static void main(String[] args) throws Exception{
                Test1 test = new Test1();

                String namespace = "http://tempuri.org";;
                String methodName = "echo";

                System.out.println("File exists - "+new
File("test.txt").exists());
                DataHandler dh = new DataHandler(new
File("test.txt").toURL());
                System.out.println("File Name - "+dh.getName());
                Object[] paramValues = {dh};

                Document doc = test.getEnvelopeAsDocument(namespace,
methodName, paramValues);
                System.out.println("Document - "+doc);
        }

        public Document getEnvelopeAsDocument(String namespace, String
methodName, Object[] paramValues) throws Exception{
                System.out.println("Creating envelope....");
                //envelope
                SOAPEnvelope env = new SOAPEnvelope();
                env.addMapping(new Mapping(SOAPSECNS, SOAPSECprefix));
                env.addAttribute(Constants.URI_SOAP11_ENV, "actor",
"http://tempuri.org";);
                env.addAttribute(Constants.URI_SOAP11_ENV, "mustUnderstand",
"1");

                System.out.println("Creating envelope.header....");
                //Header
                SOAPHeaderElement header = new
SOAPHeaderElement(XMLUtils.StringToElement(SOAPSECNS, "Signature", ""));
                env.addHeader(header);

                System.out.println("Creating envelope.body....");
                RPCElement bodyInfo = new RPCElement(namespace, methodName,
paramValues);
                env.addBodyElement(bodyInfo);

                System.out.println("");
                System.out.println("Envelope is ready. ---ENVELOPE
STARTS----");
                System.out.println("Is envelope NULL? - "+(env == null));
                System.out.println(env);
                System.out.println("Envelope is ready. ---ENVELOPE
ENDS----");
                System.out.println("");

                //Get as doc
                System.out.println("Trying to create document....");
                Document doc = getSOAPEnvelopeAsDocument(env);
                System.out.println("Document creation success");
                return doc;
        }

        private Document getSOAPEnvelopeAsDocument(SOAPEnvelope env) throws
Exception{
                MessageContext msgContext = null;

                StringWriter writer = new StringWriter();
                SerializationContext serializeContext = new
SerializationContextImpl(writer, msgContext);
                env.output(serializeContext);
                writer.close();

                Reader reader = new
StringReader(writer.getBuffer().toString());
                Document doc = XMLUtils.newDocument(new
InputSource(reader));
                if (doc == null){
                        throw new Exception(Messages.getMessage("noDoc00",
writer.getBuffer().toString()));
                }
                return doc;
        }
}