null pointer exception

[V.Preetha]

hi           when I run the user guide sample, the service gets deployed without any problem.   But when I run the client I get the following error message.     log4j:WARN No appenders could be found for logger (org.apache.axiom.om.impl.builder.StAXOMBuilder).   log4j:WARN Please initialize the log4j system properly.   org.apache.axis2.AxisFault: null; nested exception is:           java.lang.NullPointerException           at org.apache.axis2.description.OutInAxisOperationClient.execute(OutInAxisO peration.java:287)             at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:457 )           at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:399 )           at EchoBlockingClient.main(EchoBlockingClient.java:47)   Caused by: java.lang.Exception: org.apache.axis2.AxisFault: null; nested exception is:           java.lang.NullPointerException           at org.apache.axis2.AxisFault.makeFault(AxisFault.java:318)           at org.apache.axis2.rpc.receivers.RPCMessageReceiver.invokeBusinessLogic(RP CMessageReceiver.j   ava:136)           at org.apache.axis2.receivers.AbstractInOutSyncMessageReceiver.receive(Abst ractInOutSyncMessa   geReceiver.java:37)           at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:454)           at org.apache.axis2.transport.http.HTTPTransportUtils.processHTTPPostReques t(HTTPTransportUti   ls.java:284)           at org.apache.axis2.transport.http.HTTPWorker.processRequest(HTTPWorker.jav a:255)           at org.apache.axis2.transport.http.server.SimpleConnectionThread.run(Simple ConnectionThread.j   ava:92)           at edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker .runTask(ThreadPoo   lExecutor.java:650)           at edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker .run(ThreadPoolExe   cutor.java:675)           at java.lang.Thread.run(Thread.java:534)   Caused by: java.lang.NullPointerException           at org.apache.axis2.rpc.receivers.RPCMessageReceiver.invokeBusinessLogic(RP CMessageReceiver.j   ava:84)           ... 8 more             at org.apache.axis2.AxisFault.<init>(AxisFault.java:159)           ... 4 more     Please do help me on this. Is there any initialization I have to do to run a service and a client.     I'm using inbuilt HTTP server     Regards,   Preetha V.     DISCLAIMER: This message contains privileged and confidential information and is intended only for the individual named.If you are not the intended recipient you should not disseminate,distribute,store,print, copy or deliver this message.Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system.E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted,corrupted,lost,destroyed,arrive late or incomplete or contain viruses.The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version.