Hi, i am new to webservice. i have developed a EJB and exposed it as webservice. i have deployed my EJB in JBOSS 5. Business Logic and inteface is as below package com.sample; @Remote @WebService public interface SampleEJBRemote { @WebMethod public SampleResult getDetails(String name, String value); } business class: @Stateless @WebService(endpointInterface="com.sample.SampleEJBRemote") public class SampleEJB implements SampleEJBRemote { public SampleResult getDetails(String name, String value){ Map resultObj = getData(); SampleResult result = new SampleResult(); result.setOutput(resultObj); } private Map getData(){ HashMap propsMap = new HashMap(); for(int i =0 ; i < 10; i++){ HashMap prop = new HashMap(); prop.put("name",i + "Count"); propsMap.put(i,prop); } return propsMap; } } For the above code i created an ear and deployed in JBOSS and it works fine for EJB mode. When i invoke the same method using WebService i am getting the below error: [javax.xml.bind.JAXBException: class java.util.HashMap nor any of its super class is known to this context.] i have generated the client proxy for webservice using wsgen tool. Kindly help me. As i am new to this WebService's and EJB's . Regards Sivaraj R