Why my object always throw NULLPointerException

Hi

i have a JSF page

and in managed bean i declared something as below

privatestatic myObjectListDataProvider =new myObjectListDataProvider();

public myObjectListDataProvider getMyObjectListDataProvider(){

return myObjectListDatProvider();

}

and in my search button action

publicvoid search_button_action(){

myObjectListDataProvider.removeRow(....); ->this line keep giving me NULL Pointer Exception

}

I know this sounds trivial but

I am so frustated and i have checked that in the entire page itself there is no action to set this object to NULL.

I would like to know in which scenario this object can be destroy and set it Back to NULL

the full stack trace as below

java.lang.NullPointerException

at Page1.btnSearch_action(Page1.java:1170)

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:585)

at com.sun.faces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:126)

at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:72)

at com.sun.rave.web.ui.appbase.faces.ActionListenerImpl.processAction(ActionListenerImpl.java:57)

at javax.faces.component.UICommand.broadcast(UICommand.java:312)

at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:267)

at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:381)

at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:75)

at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:221)

at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:90)

at javax.faces.webapp.FacesServlet.service(FacesServlet.java:197)

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:585)

at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:249)

at java.security.AccessController.doPrivileged(Native Method)

at javax.security.auth.Subject.doAsPrivileged(Subject.java:517)

at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:282)

at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:165)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:257)

at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:55)

at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:161)

at java.security.AccessController.doPrivileged(Native Method)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)

at com.sun.rave.web.ui.util.UploadFilter.doFilter(UploadFilter.java:194)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:210)

at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:55)

at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:161)

at java.security.AccessController.doPrivileged(Native Method)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:263)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:551)

at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:225)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:173)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:551)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:551)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:132)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:551)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:933)

at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:189)

at com.sun.enterprise.web.connector.grizzly.ProcessorTask.doProcess(ProcessorTask.java:604)

at com.sun.enterprise.web.connector.grizzly.ProcessorTask.process(ProcessorTask.java:475)

at com.sun.enterprise.web.connector.grizzly.ReadTask.executeProcessorTask(ReadTask.java:371)

at com.sun.enterprise.web.connector.grizzly.ReadTask.doTask(ReadTask.java:264)

at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:281)

at com.sun.enterprise.web.connector.grizzly.WorkerThread.run(WorkerThread.java:83)

[5604 byte] By [just_a_kid83] at [2007-11-26 10:00:56]
# 1
Finally i got it up...It turns out that because i am using Springand there is duplicated entry in Managed-Beans.xmlI wonder why there is no validation in Managed-beans.xml if you have two duplicated entry with the same managed-bean name
just_a_kid83 at 2007-7-7 1:30:35 > top of Java-index,Development Tools,Java Tools...