Unable to create JavaBean of type... maybe a name space problem

[Yu Chen]

Hi, all.

my client throws a SAXException as bellow:

org.xml.sax.SAXException: Unable to create JavaBean of type 
de.uni.karlsruhe.info.telematik.snmp.client.Task.  Missing default constructor?  Error 
was: java.lang.InstantiationException: 
de.uni.karlsruhe.info.telematik.snmp.client.Task.
        at 
org.apache.axis.message.SOAPFaultBuilder.endElement(SOAPFaultBuilder.java:135)
        at 
org.apache.axis.encoding.DeserializationContextImpl.endElement(DeserializationContextImpl.java:904)

        at org.apache.xerces.parsers.SAXParser.endElement(SAXParser.java:1403)
        at 
org.apache.xerces.validators.common.XMLValidator.callEndElement(XMLValidator.java:1550)

        at 
org.apache.xerces.framework.XMLDocumentScanner$ContentDispatcher.dispatch(XMLDocumentScanner.java:1204)

        at 
org.apache.xerces.framework.XMLDocumentScanner.parseSome(XMLDocumentScanner.java:381)
        at org.apache.xerces.framework.XMLParser.parse(XMLParser.java:1098)
        at javax.xml.parsers.SAXParser.parse(SAXParser.java:345)
        at 
org.apache.axis.encoding.DeserializationContextImpl.parse(DeserializationContextImpl.java:213)

        at org.apache.axis.SOAPPart.getAsSOAPEnvelope(SOAPPart.java:457)
        at org.apache.axis.Message.getSOAPEnvelope(Message.java:362)
        at org.apache.axis.client.Call.invokeEngine(Call.java:2046)
        at org.apache.axis.client.Call.invoke(Call.java:2016)
        at org.apache.axis.client.Call.invoke(Call.java:1786)
        at org.apache.axis.client.Call.invoke(Call.java:1711)
        at org.apache.axis.client.Call.invoke(Call.java:1251)
        at de.uni.karlsruhe.info.telematik.snmp.client.SClient.run(SClient.java:72)
Error : org.xml.sax.SAXException: Unable to create JavaBean of type 
de.uni.karlsruhe.info.telematik.snmp.client.Task.  Missing default constructor?  Error 
was: java.lang.InstantiationException: 
de.uni.karlsruhe.info.telematik.snmp.client.Task.

my service data is  de.uni.karlsruhe.info.telematik.snmp.service.SnmpService 
and the bean class is de.uni.karlsruhe.info.telematik.snmp.client.Task

and my descriptor file is as bellow:

<deployment xmlns="http://xml.apache.org/axis/wsdd/";
            xmlns:java="http://xml.apache.org/axis/wsdd/providers/java";>

 <service name="SnmpService" provider="java:RPC">
  <parameter name="className" 
value="de.uni.karlsruhe.info.telematik.snmp.service.SnmpService"/>
  <parameter name="allowedMethods" value="*"/>
  <parameter name="scope" value="session"/>

  <beanMapping qname="myNS:Task" xmlns:myNS="SnmpService"
               
languageSpecificType="java:de.uni.karlsruhe.info.telematik.snmp.client.Task"/>
 </service>
</deployment>

It seems that the axis can not find the 
de.uni.karlsruhe.info.telematik.snmp.client.Task,  is it a name space problem?

Please help me on this on this.
need desperately
Thanks a lot!

Chen