null pointer exception on web services

I'm facing this issue when calling to a web services. Pls how to solve it.

AxisFault
 faultCode: {http://schemas.xmlsoap.org/soap/envelope/}Server.userException
 faultSubcode: 
 faultString: java.lang.NullPointerException
 faultActor: 
 faultNode: 
 faultDetail: 
    {http://xml.apache.org/axis/}stackTrace: java.lang.NullPointerException
    at java.util.Hashtable.put(Hashtable.java:396)
    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.setProperty(SAXParserImpl.java:395)
    at weblogic.xml.jaxp.WebLogicSAXParser.setProperty(WebLogicSAXParser.java:117)
    at weblogic.xml.jaxp.RegistrySAXParser.setProperty(RegistrySAXParser.java:117)
    at org.apache.axis.encoding.DeserializationContextImpl.parse(DeserializationCont开发者_如何学编程extImpl.java:246)
    at org.apache.axis.SOAPPart.getAsSOAPEnvelope(SOAPPart.java:538)
    at org.apache.axis.Message.getSOAPEnvelope(Message.java:376)
    at org.apache.axis.transport.http.HTTPSender.readFromSocket(HTTPSender.java:675)
    at org.apache.axis.transport.http.HTTPSender.invoke(HTTPSender.java:128)
    at org.apache.axis.strategies.InvocationStrategy.visit(InvocationStrategy.java:71)
    at org.apache.axis.SimpleChain.doVisiting(SimpleChain.java:150)
    at org.apache.axis.SimpleChain.invoke(SimpleChain.java:120)
    at org.apache.axis.client.AxisClient.invoke(AxisClient.java:180)
    at org.apache.axis.client.Call.invokeEngine(Call.java:2564)
    at org.apache.axis.client.Call.invoke(Call.java:2553)
    at org.apache.axis.client.Call.invoke(Call.java:2248)
    at org.apache.axis.client.Call.invoke(Call.java:2171)
    at org.apache.axis.client.Call.invoke(Call.java:1691)

Thanks in Advance..

Hashtable#put will throw a NullPointerException if the value is null. That's the technical aspect, and I don't think, we can solve much more of your error with just the stack trace.

Looks like your calling a webservice and at some point, axis wants to store a key/value pair internally but the value is null.

You may use soapUi to verify, that the webservice itself produces correct output for your request. Once your sure, that the service is working, debug your code, set breakpoints and try to find out the failing part.