Help needed to read exception

Question

Hello,
I am having problems reading an exception stack and help would be appreciated.
Following is the exception I get:
Apr 15, 2004 5:18:36 PM com.sun.faces.lifecycle.InvokeApplicationPhase execute
SEVERE: #{OPCAdvancedQueryManagedBean.beanAction}: javax.faces.el.EvaluationException: java.lang.NullPointerException
javax.faces.FacesException: #{OPCAdvancedQueryManagedBean.beanAction}: javax.faces.el.EvaluationException: java.lang.NullPointerException
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:78)
at javax.faces.component.UICommand.broadcast(UICommand.java:312)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:266)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:380)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:75)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:90)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:197)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:284)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:204)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:257)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:245)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:199)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:509)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:184)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:164)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:156)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:972)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:206)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:833)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:732)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:619)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:688)
at java.lang.Thread.run(Thread.java:536)
Caused by: javax.faces.el.EvaluationException: java.lang.NullPointerException
at com.sun.faces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:130)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:72)
... 33 more
Caused by: java.lang.NullPointerException
at com.sun.faces.context.SessionMap.put(ExternalContextImpl.java:555)
at com.softwareag.estela.opc.util.OPCSessionUtil.putTResponseIntoSession(OPCSessionUtil.java:35)
at com.softwareag.estela.opc.engine.OPCSearch.execute(OPCSearch.java:47)
at com.softwareag.estela.opc.jsf.OPCAbstractQueryManagedBean.beanAction(OPCAbstractQueryManagedBean.java:71)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.sun.faces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:126)
... 34 more
Apr 15, 2004 5:19:25 PM org.apache.catalina.core.StandardContext reload
Julien.

Answer 1

Hello all,
I am definitely stuck with this annoying NullPointerException.
I know for a fact that my response object is not null as I can print it out and a !=null test returns true. However I still get this npe exception. Some member variable of the response object must be null.
What's more, from the exception stack, can't we say the problem comes from the managed bean?
Can anyone help?
Here is my code:
public boolean execute() {
OPCServiceLocator service_locator = OPCServiceLocator.getInstance();
//TODO: externalize those two strings
TXMLObjectAccessor xmlObjectAccessor = service_locator.getTXMLObjectAccessor("http://localhost/tamino/prueba_2", "ibermarcreferencec");
TXQuery xquery = TXQuery.newInstance(opcquery.getXQuery() + footer);
try {
TResponse response = xmlObjectAccessor.xquery(xquery);
List list = OPCConvertUtil.convertResponseIntoDisplayableList(response);
if (response.hasQueryContent() && response != null) {
System.out.println("<--within block B-->");
OPCSessionUtil.putTResponseIntoSession(response);//error occurs here
OPCSessionUtil.putSearchResultsIntoSession(list);
System.out.println("<--within block E-->");
return response.hasQueryContent();
} catch (TXQueryException e) {
e.printStackTrace();
return false;
}Julien.