I have a very strange problem with SessionScoped bean in a JSF 2.0 project. Using Netbeans 6.9.1, Glassfish 3 Server, and PrimeFaces 3 as a JSF Component Library.
Here is the code:
package com.hia.jsf; import com.hia.netlabel.jpa.Genre; import com.hia.netlabel.jpa.Label; import java.io.Serializable; import java.util.List; import javax.annotation.PostConstruct; import javax.enterprise.context.SessionScoped; import javax.faces.bean.ManagedBean; import javax.faces.bean.ManagedProperty; @ManagedBean @SessionScoped public class LabelDetailJSF implements Serializable{ @ManagedProperty("#{genreLabelListJSF}") private GenreLabelListJSF genreLabelListJSF; private List<Genre> DetailLabelGenreList; private Label DetailLabel; public LabelDetailJSF() { } @PostConstruct public void init(){ System.out.print("Running init LabelDetailJSF"); if(genreLabelListJSF.getSelectedLabel()!=null) { System.out.print("genreLabelListJSF was not null"); this.DetailLabelGenreList=genreLabelListJSF.getSelectedLabel().getGenreList(); this.DetailLabel= (genreLabelListJSF.getSelectedLabel()); } if(this.DetailLabelGenreList==null){ System.out.println("Bloody thing became null"); } } public Label getDetailLabel() { return DetailLabel; } public void setDetailLabel(Label DetailLabel) { System.out.println("Setting Detail Label For LabelDetailJSF to:"+DetailLabel.getLabelName()); this.DetailLabel = DetailLabel; } public List<Genre> getDetailLabelGenreList() { System.out.println("There is:"+this.DetailLabelGenreList.size()+ " Genres available"); return DetailLabelGenreList; } public void setDetailLabelGenreList(List<Genre> DetailLabelGenreList) { System.out.println("Setting the DetailLabelGenre List to have "+DetailLabelGenreList.size()); this.DetailLabelGenreList = DetailLabelGenreList; } public GenreLabelListJSF getGenreLabelListJSF() { return genreLabelListJSF; } public void setGenreLabelListJSF(GenreLabelListJSF genreLabelListJSF) { this.genreLabelListJSF = genreLabelListJSF; } }
So basically I introduced another session bean in LabelDetailJSF called GenreLabelListJSF. I want to display a DetailLabelGenreList inside a dataTable. Here is the XHTML snippet used to display datatable
<p:dataTable id="detailLabelGenreGrid" value="# {labelDetailJSF.detailLabelGenreList}" var="genre" paginator="true" styleClass="text70" rows="2" > <p:column style="min-width:196px;"> #{genre.genreName} </p:column> </p:dataTable>
When the page loads, I first get a table with several rows. When I press the paging buttons, where the fun begins.
I checked the output from all System.out statements and found the following when the page loads initially.
INFO: Running init LabelDetailJSF INFO: genreLabelListJSF was not null INFO: There is:29 Genres available INFO: There is:29 Genres available INFO: There is:29 Genres available INFO: There is:29 Genres available INFO: There is:29 Genres available INFO: There is:29 Genres available
When I click the page buttons in the datatable file, I get the following:
INFO: Running init LabelDetailJSF INFO: Bloody thing became null SEVERE: javax.el.ELException: /LabelDetail.xhtml @62,165 value="# {labelDetailJSF.detailLabelGenreList}": java.lang.NullPointerException at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:107) at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:190) at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:178) at javax.faces.component.UIData.getValue(UIData.java:554) at org.primefaces.component.datatable.DataTable.getValue(DataTable.java:731) at javax.faces.component.UIData.getDataModel(UIData.java:1248) at javax.faces.component.UIData.setRowIndex(UIData.java:447) at javax.faces.component.UIData.visitTree(UIData.java:1184) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1457) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1457) at javax.faces.component.UIForm.visitTree(UIForm.java:333) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1457) at javax.faces.component.UIComponent.visitTree(UIComponent.java:1457) at com.sun.faces.application.view.StateManagementStrategyImpl.restoreView(StateManagementStrategyImpl.java:223) at com.sun.faces.application.StateManagerImpl.restoreView(StateManagerImpl.java:177) at com.sun.faces.application.view.ViewHandlingStrategy.restoreView(ViewHandlingStrategy.java:131) at com.sun.faces.application.view.FaceletViewHandlingStrategy.restoreView(FaceletViewHandlingStrategy.java:430) at com.sun.faces.application.view.MultiViewHandler.restoreView(MultiViewHandler.java:143) at com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:199) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:110) at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:312) at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:343) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:215) at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:215) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:277) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641) at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97) at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185) at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:226) at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165) at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791) at com.sun.grizzly.comet.CometEngine.executeServlet(CometEngine.java:473) at com.sun.grizzly.comet.CometEngine.handle(CometEngine.java:341) at com.sun.grizzly.comet.CometAsyncFilter.doFilter(CometAsyncFilter.java:84) at com.sun.grizzly.arp.DefaultAsyncExecutor.invokeFilters(DefaultAsyncExecutor.java:161) at com.sun.grizzly.arp.DefaultAsyncExecutor.interrupt(DefaultAsyncExecutor.java:137) at com.sun.grizzly.arp.AsyncProcessorTask.doTask(AsyncProcessorTask.java:88) at com.sun.grizzly.http.TaskBase.run(TaskBase.java:189) at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330) at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309) at java.lang.Thread.run(Thread.java:662) Caused by: java.lang.NullPointerException at com.hia.jsf.LabelDetailJSF.getDetailLabelGenreList(LabelDetailJSF.java:72) at sun.reflect.GeneratedMethodAccessor951.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at javax.el.BeanELResolver.getValue(BeanELResolver.java:302) at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:175) at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72) at com.sun.el.parser.AstValue.getValue(AstValue.java:116) at com.sun.el.parser.AstValue.getValue(AstValue.java:163) at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219) at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:102) ... 48 more
From what I see, it almost looks like a bean is losing scope and is constantly being recreated. Initially, the values then appear when the paging begins to bean lose value. For example, I noticed that @ManagedProperty bean also becomes null when starting a search call. Which one is crazy since it is also a bean session coverage.
Another hand in JSF, so I probably made a noob mistake. I must note that I initially created this as a ViewScoped bean by accident, and after changing the bean to SessionScoped, I did not deploy the application, restart Glassfish and build and deploy it again.
Any ideas?