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Posted to users@myfaces.apache.org by Matthias Klein <ma...@cmklein.de> on 2005/10/01 14:19:16 UTC

Null Pointer Exception with dataTable

For the past 2 days I have tried to create a simple dataTable but all I get
is a NullPointerException.
I stripped the code down to the bare minimum and now have:

LOMenu.jsp:
-----------

<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
	
<f:view>
	<f:loadBundle basename="ca.gc.nrc.iit.toml.frontend.bundles.LOMenu"
var="MessageBundle"/>
	
	<html>
		<head>
			<link href="css/stylesheet.css" rel="stylesheet"
type="text/css"/>
	
			<title>
				<h:outputText
value="#{MessageBundle.dialogtitle}" />
			</title>
		</head>

		<body>
			<h:form id="LOMenuForm">
	   
	 			<h:outputText
value="#{MessageBundle.dialogtitle}" />
	 			
				<h:dataTable value="#{bookListBean.books}"
var="book" border="1">
								
					<h:column>
						<h:outputText
value="#{book.classificationSystemName}" />
					</h:column>
					
				</h:dataTable>
				
			</h:form>
		</body>
	</html>
</f:view>


The relevant pieces of faces-config are:
-----------------------------------------

	<managed-bean>
		<managed-bean-name>bookListBean</managed-bean-name>
	
<managed-bean-class>ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean</managed-b
ean-class>
		<managed-bean-scope>session</managed-bean-scope>
	</managed-bean>
	<managed-bean>
		<managed-bean-name>book</managed-bean-name>
	
<managed-bean-class>ca.gc.nrc.iit.toml.common.ClassificationSystemBean</mana
ged-bean-class>
		<managed-bean-scope>request</managed-bean-scope>
	</managed-bean>


LOMenuBackingBean.java:
------------------------

package ca.gc.nrc.iit.toml.frontend;

import java.util.*;
import ca.gc.nrc.iit.toml.common.*;

public class LOMenuBackingBean {
	
	private Vector books = null;

	public Collection getBooks() {
		ClassificationSystemBean a = new ClassificationSystemBean(1,
"title 1", "bla", false);
		ClassificationSystemBean b = new ClassificationSystemBean(2,
"title 2", "lala", true);
		ClassificationSystemBean c = new ClassificationSystemBean(3,
"title 3", "smurf", false);
		this.books.add(a);
		this.books.add(b);
		this.books.add(c);
		return this.books;
	}


	public void setClassificationSystems(Vector classificationSystems) {
		this.books = classificationSystems;
	}
}


ClassificationSystemBean.java:
-------------------------------

package ca.gc.nrc.iit.toml.common;

public class ClassificationSystemBean implements Serializable {
	
	private String classificationSystemName;

	public String getClassificationSystemName() {
		return classificationSystemName;
	}

	public void setClassificationSystemName(String
classificationSystemName) {
		this.classificationSystemName = classificationSystemName;
	}
}


-----------------
I use MyFaces 1.0.9 and deploy the war in Tomcat 5.5.9

All I get is the following Stack Trace and I really, really don't know why.
Everything works fine if I remove the dataTable tag (in that case, all I see
is the message bundle output). But whenever I enter that dataTable, I get
the exception. No matter what I tried, I always get the exception. I even
did a copy&paste from some dataTable tutorials I found - same result.
What do I do wrong?

I have tried to work with Vector, List, Collection and others in
LOMenuBacking Bean but nothing seems to work. All I ever get is the
exception.

Thanks so much!

Matt



javax.faces.FacesException: Expression: '#{bookListBean.books}'
	at
org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
etExternalContextImpl.java:411)
	at
org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
lerImpl.java:280)
	at
org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:213)
	at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:178)
	at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
)
	at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
)
	at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:107)
	at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
	at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
ction(Http11Protocol.java:744)
	at
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
a:527)
	at
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
rkerThread.java:80)
	at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:684)
	at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.jasper.JasperException: Expression:
'#{bookListBean.books}'
	at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
70)
	at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
java:672)
	at
org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
patcher.java:463)
	at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
er.java:398)
	at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
.java:301)
	at
org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
etExternalContextImpl.java:405)
	... 17 more
org.apache.jasper.JasperException: Expression: '#{bookListBean.books}'
	at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
70)
	at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
java:672)
	at
org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
patcher.java:463)
	at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
er.java:398)
	at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
.java:301)
	at
org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
etExternalContextImpl.java:405)
	at
org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
lerImpl.java:280)
	at
org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:213)
	at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:178)
	at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
)
	at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
)
	at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:107)
	at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
	at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
ction(Http11Protocol.java:744)
	at
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
a:527)
	at
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
rkerThread.java:80)
	at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:684)
	at java.lang.Thread.run(Unknown Source)
javax.faces.el.EvaluationException: Expression: '#{bookListBean.books}'
	at
org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:466)
	at javax.faces.component.UIData.getValue(UIData.java:1173)
	at javax.faces.component.UIData.createDataModel(UIData.java:850)
	at javax.faces.component.UIData.getDataModel(UIData.java:839)
	at javax.faces.component.UIData.getRowCount(UIData.java:145)
	at
org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlT
ableRendererBase.java:128)
	at
javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:32
9)
	at
javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
	at
javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
	at
org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTag
Base.java:98)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMenu_jsp
:404)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
	at
org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
	at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
22)
	at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
java:672)
	at
org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
patcher.java:463)
	at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
er.java:398)
	at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
.java:301)
	at
org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
etExternalContextImpl.java:405)
	at
org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
lerImpl.java:280)
	at
org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:213)
	at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:178)
	at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
)
	at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
)
	at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:107)
	at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
	at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
ction(Http11Protocol.java:744)
	at
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
a:527)
	at
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
rkerThread.java:80)
	at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:684)
	at java.lang.Thread.run(Unknown Source)
Caused by: javax.faces.el.EvaluationException: Bean:
ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean, property: books
	at
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
java:423)
	at
org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.jav
a:104)
	at
org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelpe
r.java:555)
	at
org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
	at
org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
	... 43 more
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
java:419)
	... 47 more
Caused by: java.lang.NullPointerException
	at
ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBean.jav
a:21)
	... 52 more
javax.faces.el.EvaluationException: Bean:
ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean, property: books
	at
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
java:423)
	at
org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.jav
a:104)
	at
org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelpe
r.java:555)
	at
org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
	at
org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
	at javax.faces.component.UIData.getValue(UIData.java:1173)
	at javax.faces.component.UIData.createDataModel(UIData.java:850)
	at javax.faces.component.UIData.getDataModel(UIData.java:839)
	at javax.faces.component.UIData.getRowCount(UIData.java:145)
	at
org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlT
ableRendererBase.java:128)
	at
javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:32
9)
	at
javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
	at
javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
	at
org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTag
Base.java:98)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMenu_jsp
:404)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
	at
org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
	at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
22)
	at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
java:672)
	at
org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
patcher.java:463)
	at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
er.java:398)
	at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
.java:301)
	at
org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
etExternalContextImpl.java:405)
	at
org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
lerImpl.java:280)
	at
org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:213)
	at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:178)
	at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
)
	at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
)
	at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:107)
	at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
	at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
ction(Http11Protocol.java:744)
	at
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
a:527)
	at
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
rkerThread.java:80)
	at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:684)
	at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
java:419)
	... 47 more
Caused by: java.lang.NullPointerException
	at
ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBean.jav
a:21)
	... 52 more
java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
java:419)
	at
org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.jav
a:104)
	at
org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelpe
r.java:555)
	at
org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
	at
org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
	at javax.faces.component.UIData.getValue(UIData.java:1173)
	at javax.faces.component.UIData.createDataModel(UIData.java:850)
	at javax.faces.component.UIData.getDataModel(UIData.java:839)
	at javax.faces.component.UIData.getRowCount(UIData.java:145)
	at
org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlT
ableRendererBase.java:128)
	at
javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:32
9)
	at
javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
	at
javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
	at
org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTag
Base.java:98)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMenu_jsp
:404)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
	at
org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
	at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
22)
	at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
java:672)
	at
org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
patcher.java:463)
	at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
er.java:398)
	at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
.java:301)
	at
org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
etExternalContextImpl.java:405)
	at
org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
lerImpl.java:280)
	at
org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:213)
	at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:178)
	at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
)
	at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
)
	at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:107)
	at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
	at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
ction(Http11Protocol.java:744)
	at
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
a:527)
	at
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
rkerThread.java:80)
	at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:684)
	at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
	at
ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBean.jav
a:21)
	... 52 more
java.lang.NullPointerException
	at
ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBean.jav
a:21)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
java:419)
	at
org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.jav
a:104)
	at
org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelpe
r.java:555)
	at
org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
	at
org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
	at javax.faces.component.UIData.getValue(UIData.java:1173)
	at javax.faces.component.UIData.createDataModel(UIData.java:850)
	at javax.faces.component.UIData.getDataModel(UIData.java:839)
	at javax.faces.component.UIData.getRowCount(UIData.java:145)
	at
org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlT
ableRendererBase.java:128)
	at
javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:32
9)
	at
javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
	at
javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
	at
org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTag
Base.java:98)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMenu_jsp
:404)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
	at
org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
	at
org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
	at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
22)
	at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
java:672)
	at
org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
patcher.java:463)
	at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
er.java:398)
	at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
.java:301)
	at
org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
etExternalContextImpl.java:405)
	at
org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
lerImpl.java:280)
	at
org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
	at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:252)
	at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:173)
	at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:213)
	at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:178)
	at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
)
	at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
)
	at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:107)
	at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
	at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
ction(Http11Protocol.java:744)
	at
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
a:527)
	at
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
rkerThread.java:80)
	at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:684)
	at java.lang.Thread.run(Unknown Source)

RE: Null Pointer Exception with dataTable

Posted by Matthias Klein <ma...@cmklein.de>.

I don't believe it. Now it works.
Was my mistake that I forgot to create an instance of Vector (books)? 
Thanks
Matt
 

-----Original Message-----
From: Larry Meadors [mailto:larry.meadors@gmail.com] 
Sent: Samstag, 1. Oktober 2005 14:26
To: MyFaces Discussion
Subject: Re: Null Pointer Exception with dataTable

Vector?

Hmm, ok.

Change this:
 public Collection getBooks() {
  books = new Vector();
 ... rest of method here...
 }

Larry


On 10/1/05, Matthias Klein <ma...@cmklein.de> wrote:
> For the past 2 days I have tried to create a simple dataTable but all 
> I get is a NullPointerException.
> I stripped the code down to the bare minimum and now have:
>
> LOMenu.jsp:
> -----------
>
> <%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %> <%@ taglib 
> uri="http://java.sun.com/jsf/core" prefix="f" %>
>
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
>
> <f:view>
>         <f:loadBundle
basename="ca.gc.nrc.iit.toml.frontend.bundles.LOMenu"
> var="MessageBundle"/>
>
>         <html>
>                 <head>
>                         <link href="css/stylesheet.css" rel="stylesheet"
> type="text/css"/>
>
>                         <title>
>                                 <h:outputText 
> value="#{MessageBundle.dialogtitle}" />
>                         </title>
>                 </head>
>
>                 <body>
>                         <h:form id="LOMenuForm">
>
>                                 <h:outputText 
> value="#{MessageBundle.dialogtitle}" />
>
>                                 <h:dataTable value="#{bookListBean.books}"
> var="book" border="1">
>
>                                         <h:column>
>                                                 <h:outputText 
> value="#{book.classificationSystemName}" />
>                                         </h:column>
>
>                                 </h:dataTable>
>
>                         </h:form>
>                 </body>
>         </html>
> </f:view>
>
>
> The relevant pieces of faces-config are:
> -----------------------------------------
>
>         <managed-bean>
>                 <managed-bean-name>bookListBean</managed-bean-name>
>
> <managed-bean-class>ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean</man
> aged-b
> ean-class>
>                 <managed-bean-scope>session</managed-bean-scope>
>         </managed-bean>
>         <managed-bean>
>                 <managed-bean-name>book</managed-bean-name>
>
> <managed-bean-class>ca.gc.nrc.iit.toml.common.ClassificationSystemBean
> </mana
> ged-bean-class>
>                 <managed-bean-scope>request</managed-bean-scope>
>         </managed-bean>
>
>
> LOMenuBackingBean.java:
> ------------------------
>
> package ca.gc.nrc.iit.toml.frontend;
>
> import java.util.*;
> import ca.gc.nrc.iit.toml.common.*;
>
> public class LOMenuBackingBean {
>
>         private Vector books = null;
>
>         public Collection getBooks() {
>                 ClassificationSystemBean a = new 
> ClassificationSystemBean(1, "title 1", "bla", false);
>                 ClassificationSystemBean b = new 
> ClassificationSystemBean(2, "title 2", "lala", true);
>                 ClassificationSystemBean c = new 
> ClassificationSystemBean(3, "title 3", "smurf", false);
>                 this.books.add(a);
>                 this.books.add(b);
>                 this.books.add(c);
>                 return this.books;
>         }
>
>
>         public void setClassificationSystems(Vector classificationSystems)
{
>                 this.books = classificationSystems;
>         }
> }
>
>
> ClassificationSystemBean.java:
> -------------------------------
>
> package ca.gc.nrc.iit.toml.common;
>
> public class ClassificationSystemBean implements Serializable {
>
>         private String classificationSystemName;
>
>         public String getClassificationSystemName() {
>                 return classificationSystemName;
>         }
>
>         public void setClassificationSystemName(String
> classificationSystemName) {
>                 this.classificationSystemName = classificationSystemName;
>         }
> }
>
>
> -----------------
> I use MyFaces 1.0.9 and deploy the war in Tomcat 5.5.9
>
> All I get is the following Stack Trace and I really, really don't know
why.
> Everything works fine if I remove the dataTable tag (in that case, all 
> I see is the message bundle output). But whenever I enter that 
> dataTable, I get the exception. No matter what I tried, I always get 
> the exception. I even did a copy&paste from some dataTable tutorials I
found - same result.
> What do I do wrong?
>
> I have tried to work with Vector, List, Collection and others in 
> LOMenuBacking Bean but nothing seems to work. All I ever get is the 
> exception.
>
> Thanks so much!
>
> Matt
>
>
>
> javax.faces.FacesException: Expression: '#{bookListBean.books}'
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch
> (Servl
> etExternalContextImpl.java:411)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspVi
> ewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVa
> lve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextVa
> lve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.ja
> va:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.ja
> va:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValv
> e.java
> :107)
>         at
>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proces
> sConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoi
> nt.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFoll
> owerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPo
> ol.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source) Caused by: 
> org.apache.jasper.JasperException: Expression:
> '#{bookListBean.books}'
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.
> java:3
> 70)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
>
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(Applicat
> ionDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDi
> spatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDisp
> atcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch
> (Servl
> etExternalContextImpl.java:405)
>         ... 17 more
> org.apache.jasper.JasperException: Expression: '#{bookListBean.books}'
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.
> java:3
> 70)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
>
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(Applicat
> ionDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDi
> spatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDisp
> atcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch
> (Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspVi
> ewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVa
> lve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextVa
> lve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.ja
> va:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.ja
> va:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValv
> e.java
> :107)
>         at
>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proces
> sConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoi
> nt.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFoll
> owerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPo
> ol.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source)
> javax.faces.el.EvaluationException: Expression: '#{bookListBean.books}'
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:466)
>         at javax.faces.component.UIData.getValue(UIData.java:1173)
>         at javax.faces.component.UIData.createDataModel(UIData.java:850)
>         at javax.faces.component.UIData.getDataModel(UIData.java:839)
>         at javax.faces.component.UIData.getRowCount(UIData.java:145)
>         at
> org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren
> (HtmlT
> ableRendererBase.java:128)
>         at
> javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.j
> ava:32
> 9)
>         at
> javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
>         at
> javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
>         at
> org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentB
> odyTag
> Base.java:98)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMe
> nu_jsp
> :404)
>         at
>
org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
>         at
>
org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
>         at
> org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
>         at
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.
> java:3
> 22)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
>
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(Applicat
> ionDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDi
> spatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDisp
> atcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch
> (Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspVi
> ewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVa
> lve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextVa
> lve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.ja
> va:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.ja
> va:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValv
> e.java
> :107)
>         at
>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proces
> sConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoi
> nt.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFoll
> owerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPo
> ol.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source) Caused by: 
> javax.faces.el.EvaluationException: Bean:
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean, property: books
>         at
>
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:423)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverIm
> pl.jav
> a:104)
>         at
> org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParse
> rHelpe
> r.java:555)
>         at
> org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
>         ... 43 more
> Caused by: java.lang.reflect.InvocationTargetException
>         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>         at java.lang.reflect.Method.invoke(Unknown Source)
>         at
>
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:419)
>         ... 47 more
> Caused by: java.lang.NullPointerException
>         at
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBe
> an.jav
> a:21)
>         ... 52 more
> javax.faces.el.EvaluationException: Bean:
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean, property: books
>         at
>
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:423)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverIm
> pl.jav
> a:104)
>         at
> org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParse
> rHelpe
> r.java:555)
>         at
> org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
>         at javax.faces.component.UIData.getValue(UIData.java:1173)
>         at javax.faces.component.UIData.createDataModel(UIData.java:850)
>         at javax.faces.component.UIData.getDataModel(UIData.java:839)
>         at javax.faces.component.UIData.getRowCount(UIData.java:145)
>         at
> org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren
> (HtmlT
> ableRendererBase.java:128)
>         at
> javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.j
> ava:32
> 9)
>         at
> javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
>         at
> javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
>         at
> org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentB
> odyTag
> Base.java:98)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMe
> nu_jsp
> :404)
>         at
>
org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
>         at
>
org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
>         at
> org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
>         at
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.
> java:3
> 22)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
>
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(Applicat
> ionDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDi
> spatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDisp
> atcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch
> (Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspVi
> ewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVa
> lve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextVa
> lve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.ja
> va:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.ja
> va:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValv
> e.java
> :107)
>         at
>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proces
> sConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoi
> nt.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFoll
> owerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPo
> ol.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source) Caused by: 
> java.lang.reflect.InvocationTargetException
>         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>         at java.lang.reflect.Method.invoke(Unknown Source)
>         at
>
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:419)
>         ... 47 more
> Caused by: java.lang.NullPointerException
>         at
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBe
> an.jav
> a:21)
>         ... 52 more
> java.lang.reflect.InvocationTargetException
>         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>         at java.lang.reflect.Method.invoke(Unknown Source)
>         at
>
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:419)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverIm
> pl.jav
> a:104)
>         at
> org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParse
> rHelpe
> r.java:555)
>         at
> org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
>         at javax.faces.component.UIData.getValue(UIData.java:1173)
>         at javax.faces.component.UIData.createDataModel(UIData.java:850)
>         at javax.faces.component.UIData.getDataModel(UIData.java:839)
>         at javax.faces.component.UIData.getRowCount(UIData.java:145)
>         at
> org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren
> (HtmlT
> ableRendererBase.java:128)
>         at
> javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.j
> ava:32
> 9)
>         at
> javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
>         at
> javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
>         at
> org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentB
> odyTag
> Base.java:98)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMe
> nu_jsp
> :404)
>         at
>
org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
>         at
>
org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
>         at
> org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
>         at
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.
> java:3
> 22)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
>
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(Applicat
> ionDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDi
> spatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDisp
> atcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch
> (Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspVi
> ewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVa
> lve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextVa
> lve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.ja
> va:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.ja
> va:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValv
> e.java
> :107)
>         at
>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proces
> sConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoi
> nt.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFoll
> owerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPo
> ol.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source) Caused by: 
> java.lang.NullPointerException
>         at
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBe
> an.jav
> a:21)
>         ... 52 more
> java.lang.NullPointerException
>         at
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBe
> an.jav
> a:21)
>         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>         at java.lang.reflect.Method.invoke(Unknown Source)
>         at
>
org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:419)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverIm
> pl.jav
> a:104)
>         at
> org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParse
> rHelpe
> r.java:555)
>         at
> org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
>         at javax.faces.component.UIData.getValue(UIData.java:1173)
>         at javax.faces.component.UIData.createDataModel(UIData.java:850)
>         at javax.faces.component.UIData.getDataModel(UIData.java:839)
>         at javax.faces.component.UIData.getRowCount(UIData.java:145)
>         at
> org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren
> (HtmlT
> ableRendererBase.java:128)
>         at
> javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.j
> ava:32
> 9)
>         at
> javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
>         at
> javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
>         at
> org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentB
> odyTag
> Base.java:98)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMe
> nu_jsp
> :404)
>         at
>
org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
>         at
>
org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
>         at
> org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
>         at
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.
> java:3
> 22)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
>
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(Applicat
> ionDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDi
> spatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDisp
> atcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch
> (Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspVi
> ewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appli
> cation
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFi
> lterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVa
> lve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextVa
> lve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.ja
> va:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.ja
> va:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValv
> e.java
> :107)
>         at
>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proces
> sConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoi
> nt.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFoll
> owerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPo
> ol.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source)
>
>

Re: Null Pointer Exception with dataTable

Posted by Larry Meadors <la...@gmail.com>.

Vector?

Hmm, ok.

Change this:
 public Collection getBooks() {
  books = new Vector();
 ... rest of method here...
 }

Larry


On 10/1/05, Matthias Klein <ma...@cmklein.de> wrote:
> For the past 2 days I have tried to create a simple dataTable but all I get
> is a NullPointerException.
> I stripped the code down to the bare minimum and now have:
>
> LOMenu.jsp:
> -----------
>
> <%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
> <%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
>
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
>
> <f:view>
>         <f:loadBundle basename="ca.gc.nrc.iit.toml.frontend.bundles.LOMenu"
> var="MessageBundle"/>
>
>         <html>
>                 <head>
>                         <link href="css/stylesheet.css" rel="stylesheet"
> type="text/css"/>
>
>                         <title>
>                                 <h:outputText
> value="#{MessageBundle.dialogtitle}" />
>                         </title>
>                 </head>
>
>                 <body>
>                         <h:form id="LOMenuForm">
>
>                                 <h:outputText
> value="#{MessageBundle.dialogtitle}" />
>
>                                 <h:dataTable value="#{bookListBean.books}"
> var="book" border="1">
>
>                                         <h:column>
>                                                 <h:outputText
> value="#{book.classificationSystemName}" />
>                                         </h:column>
>
>                                 </h:dataTable>
>
>                         </h:form>
>                 </body>
>         </html>
> </f:view>
>
>
> The relevant pieces of faces-config are:
> -----------------------------------------
>
>         <managed-bean>
>                 <managed-bean-name>bookListBean</managed-bean-name>
>
> <managed-bean-class>ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean</managed-b
> ean-class>
>                 <managed-bean-scope>session</managed-bean-scope>
>         </managed-bean>
>         <managed-bean>
>                 <managed-bean-name>book</managed-bean-name>
>
> <managed-bean-class>ca.gc.nrc.iit.toml.common.ClassificationSystemBean</mana
> ged-bean-class>
>                 <managed-bean-scope>request</managed-bean-scope>
>         </managed-bean>
>
>
> LOMenuBackingBean.java:
> ------------------------
>
> package ca.gc.nrc.iit.toml.frontend;
>
> import java.util.*;
> import ca.gc.nrc.iit.toml.common.*;
>
> public class LOMenuBackingBean {
>
>         private Vector books = null;
>
>         public Collection getBooks() {
>                 ClassificationSystemBean a = new ClassificationSystemBean(1,
> "title 1", "bla", false);
>                 ClassificationSystemBean b = new ClassificationSystemBean(2,
> "title 2", "lala", true);
>                 ClassificationSystemBean c = new ClassificationSystemBean(3,
> "title 3", "smurf", false);
>                 this.books.add(a);
>                 this.books.add(b);
>                 this.books.add(c);
>                 return this.books;
>         }
>
>
>         public void setClassificationSystems(Vector classificationSystems) {
>                 this.books = classificationSystems;
>         }
> }
>
>
> ClassificationSystemBean.java:
> -------------------------------
>
> package ca.gc.nrc.iit.toml.common;
>
> public class ClassificationSystemBean implements Serializable {
>
>         private String classificationSystemName;
>
>         public String getClassificationSystemName() {
>                 return classificationSystemName;
>         }
>
>         public void setClassificationSystemName(String
> classificationSystemName) {
>                 this.classificationSystemName = classificationSystemName;
>         }
> }
>
>
> -----------------
> I use MyFaces 1.0.9 and deploy the war in Tomcat 5.5.9
>
> All I get is the following Stack Trace and I really, really don't know why.
> Everything works fine if I remove the dataTable tag (in that case, all I see
> is the message bundle output). But whenever I enter that dataTable, I get
> the exception. No matter what I tried, I always get the exception. I even
> did a copy&paste from some dataTable tutorials I found - same result.
> What do I do wrong?
>
> I have tried to work with Vector, List, Collection and others in
> LOMenuBacking Bean but nothing seems to work. All I ever get is the
> exception.
>
> Thanks so much!
>
> Matt
>
>
>
> javax.faces.FacesException: Expression: '#{bookListBean.books}'
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
> etExternalContextImpl.java:411)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :107)
>         at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source)
> Caused by: org.apache.jasper.JasperException: Expression:
> '#{bookListBean.books}'
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
> 70)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
> etExternalContextImpl.java:405)
>         ... 17 more
> org.apache.jasper.JasperException: Expression: '#{bookListBean.books}'
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
> 70)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :107)
>         at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source)
> javax.faces.el.EvaluationException: Expression: '#{bookListBean.books}'
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:466)
>         at javax.faces.component.UIData.getValue(UIData.java:1173)
>         at javax.faces.component.UIData.createDataModel(UIData.java:850)
>         at javax.faces.component.UIData.getDataModel(UIData.java:839)
>         at javax.faces.component.UIData.getRowCount(UIData.java:145)
>         at
> org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlT
> ableRendererBase.java:128)
>         at
> javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:32
> 9)
>         at
> javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
>         at
> javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
>         at
> org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTag
> Base.java:98)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMenu_jsp
> :404)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
>         at
> org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
>         at
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
> 22)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :107)
>         at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source)
> Caused by: javax.faces.el.EvaluationException: Bean:
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean, property: books
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:423)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.jav
> a:104)
>         at
> org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelpe
> r.java:555)
>         at
> org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
>         ... 43 more
> Caused by: java.lang.reflect.InvocationTargetException
>         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>         at java.lang.reflect.Method.invoke(Unknown Source)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:419)
>         ... 47 more
> Caused by: java.lang.NullPointerException
>         at
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBean.jav
> a:21)
>         ... 52 more
> javax.faces.el.EvaluationException: Bean:
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean, property: books
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:423)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.jav
> a:104)
>         at
> org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelpe
> r.java:555)
>         at
> org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
>         at javax.faces.component.UIData.getValue(UIData.java:1173)
>         at javax.faces.component.UIData.createDataModel(UIData.java:850)
>         at javax.faces.component.UIData.getDataModel(UIData.java:839)
>         at javax.faces.component.UIData.getRowCount(UIData.java:145)
>         at
> org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlT
> ableRendererBase.java:128)
>         at
> javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:32
> 9)
>         at
> javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
>         at
> javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
>         at
> org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTag
> Base.java:98)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMenu_jsp
> :404)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
>         at
> org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
>         at
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
> 22)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :107)
>         at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source)
> Caused by: java.lang.reflect.InvocationTargetException
>         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>         at java.lang.reflect.Method.invoke(Unknown Source)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:419)
>         ... 47 more
> Caused by: java.lang.NullPointerException
>         at
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBean.jav
> a:21)
>         ... 52 more
> java.lang.reflect.InvocationTargetException
>         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>         at java.lang.reflect.Method.invoke(Unknown Source)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:419)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.jav
> a:104)
>         at
> org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelpe
> r.java:555)
>         at
> org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
>         at javax.faces.component.UIData.getValue(UIData.java:1173)
>         at javax.faces.component.UIData.createDataModel(UIData.java:850)
>         at javax.faces.component.UIData.getDataModel(UIData.java:839)
>         at javax.faces.component.UIData.getRowCount(UIData.java:145)
>         at
> org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlT
> ableRendererBase.java:128)
>         at
> javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:32
> 9)
>         at
> javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
>         at
> javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
>         at
> org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTag
> Base.java:98)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMenu_jsp
> :404)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
>         at
> org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
>         at
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
> 22)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :107)
>         at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source)
> Caused by: java.lang.NullPointerException
>         at
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBean.jav
> a:21)
>         ... 52 more
> java.lang.NullPointerException
>         at
> ca.gc.nrc.iit.toml.frontend.LOMenuBackingBean.getBooks(LOMenuBackingBean.jav
> a:21)
>         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>         at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>         at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>         at java.lang.reflect.Method.invoke(Unknown Source)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.
> java:419)
>         at
> org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.jav
> a:104)
>         at
> org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelpe
> r.java:555)
>         at
> org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
>         at
> org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:441)
>         at javax.faces.component.UIData.getValue(UIData.java:1173)
>         at javax.faces.component.UIData.createDataModel(UIData.java:850)
>         at javax.faces.component.UIData.getDataModel(UIData.java:839)
>         at javax.faces.component.UIData.getRowCount(UIData.java:145)
>         at
> org.apache.myfaces.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlT
> ableRendererBase.java:128)
>         at
> javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:32
> 9)
>         at
> javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:380)
>         at
> javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:288)
>         at
> org.apache.myfaces.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTag
> Base.java:98)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_dataTable_0(org.apache.jsp.LOMenu_jsp
> :404)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_h_form_0(org.apache.jsp.LOMenu_jsp:342)
>         at
> org.apache.jsp.LOMenu_jsp._jspx_meth_f_view_0(org.apache.jsp.LOMenu_jsp:138)
>         at
> org.apache.jsp.LOMenu_jsp._jspService(org.apache.jsp.LOMenu_jsp:76)
>         at
> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:3
> 22)
>         at
> org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
>         at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
>         at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.
> java:672)
>         at
> org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDis
> patcher.java:463)
>         at
> org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatch
> er.java:398)
>         at
> org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher
> .java:301)
>         at
> org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(Servl
> etExternalContextImpl.java:405)
>         at
> org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHand
> lerImpl.java:280)
>         at
> org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:300)
>         at javax.faces.webapp.FacesServlet.service(FacesServlet.java:110)
>         at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:252)
>         at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:173)
>         at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:213)
>         at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:178)
>         at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126
> )
>         at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105
> )
>         at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :107)
>         at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
>         at
> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
>         at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
> ction(Http11Protocol.java:744)
>         at
> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.jav
> a:527)
>         at
> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWo
> rkerThread.java:80)
>         at
> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
> a:684)
>         at java.lang.Thread.run(Unknown Source)
>
>