Initialize controller bean

[samvimes]

Hi everyone,
I am currently developing a web application using Richfaces 3.3.1 with Spring and Facelets.

I want to initialize a request scoped controller bean with values later used in a selectonemenu. these values are loaded from database in a init method annotated with @PostConstruct.

My problem is that although the bean uses the a4j:keepAlive tag the init method is called every time I click a button on the page (and therefore everytime data is loaded from the database). As far as I understood the bean is serialized and the constructor is called on each request. Does that mean that also @PostConstruct is called every time?

Is this the expected behavior? And if not what is the suggested way to initialize the controller bean when using a4j:keepAlive?

Best Regards
Carsten

[samvimes]

Hi,
I just did a few test. The page contains a rich:extendedDataTable component with a binding. If I remove the binding the @PostContruct method is called only once. With the binding the @PostContruct method is called on each request. Is this a bug?

[samvimes]

Actually if the page contains ANY component binding then the method is called on each request. Any suggestions how to solve this problem?

[nbelaevski]

Can you please add

Thread.dumpStack();

to init method and post dumped stack trace here?

[samvimes]

This is the call to the init method when opening the page:

Stack trace
 at java.lang.Thread.dumpStack(Unknown Source)
 at controller.admin.TestPage.init(TestPage.java:61)
 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.catalina.util.DefaultAnnotationProcessor.postConstruct(DefaultAnnotationProcessor.java:96)
 at com.sun.faces.vendor.Tomcat6InjectionProvider.invokePostConstruct(Tomcat6InjectionProvider.java:118)
 at com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:220)
 at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:108)
 at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:368)
 at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:230)
 at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:86)
 at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
 at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
 at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:61)
 at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
 at com.sun.faces.application.ValueBindingValueExpressionAdapter.getValue(ValueBindingValueExpressionAdapter.java:113)
 at org.ajax4jsf.taglib.html.facelets.KeepAliveHandler.apply(KeepAliveHandler.java:76)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.tag.ui.DefineHandler.applyDefinition(DefineHandler.java:64)
 at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:131)
 at com.sun.facelets.impl.DefaultFaceletContext$TemplateManager.apply(DefaultFaceletContext.java:310)
 at com.sun.facelets.impl.DefaultFaceletContext.includeDefinition(DefaultFaceletContext.java:280)
 at com.sun.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:68)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:248)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:294)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:273)
 at com.sun.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:144)
 at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:113)
 at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
 at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:248)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:294)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:273)
 at com.sun.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:144)
 at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:113)
 at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
 at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
 at com.sun.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:95)
 at com.sun.facelets.FaceletViewHandler.buildView(FaceletViewHandler.java:524)
 at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:567)
 at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:100)
 at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:176)
 at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:110)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
 at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:266)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
 at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
 at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:368)
 at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:495)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
 at java.lang.Thread.run(Unknown Source)

And this is the stack trace when I clicked on the button:

Stack trace
 at java.lang.Thread.dumpStack(Unknown Source)
 at controller.admin.TestPage.init(TestPage.java:61)
 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.catalina.util.DefaultAnnotationProcessor.postConstruct(DefaultAnnotationProcessor.java:96)
 at com.sun.faces.vendor.Tomcat6InjectionProvider.invokePostConstruct(Tomcat6InjectionProvider.java:118)
 at com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:220)
 at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:108)
 at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:368)
 at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:230)
 at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:86)
 at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:54)
 at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72)
 at org.apache.el.parser.AstIdentifier.getValue(AstIdentifier.java:61)
 at org.apache.el.parser.AstValue.getTarget(AstValue.java:63)
 at org.apache.el.parser.AstValue.setValue(AstValue.java:133)
 at org.apache.el.ValueExpressionImpl.setValue(ValueExpressionImpl.java:249)
 at com.sun.facelets.el.TagValueExpression.setValue(TagValueExpression.java:93)
 at com.sun.faces.lifecycle.RestoreViewPhase.doPerComponentActions(RestoreViewPhase.java:238)
 at com.sun.faces.lifecycle.RestoreViewPhase.doPerComponentActions(RestoreViewPhase.java:243)
 at com.sun.faces.lifecycle.RestoreViewPhase.doPerComponentActions(RestoreViewPhase.java:243)
 at com.sun.faces.lifecycle.RestoreViewPhase.doPerComponentActions(RestoreViewPhase.java:243)
 at com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:198)
 at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
 at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:102)
 at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178)
 at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
 at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:368)
 at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:495)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
 at java.lang.Thread.run(Unknown Source)

[samvimes]

I hve build a simple page to reproduce the behavior:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
 xmlns:ui="http://java.sun.com/jsf/facelets"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:h="http://java.sun.com/jsf/html"
 xmlns:a4j="http://richfaces.org/a4j"
 xmlns:rich="http://richfaces.org/rich">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</head>
<body>
 <a4j:keepAlive beanName="testPage"/>

 <a4j:form>
 <h:inputText id="input1"
 value="#{testPage.test}"
 binding="#{testPage.pageComponents.input1}" />

 <a4j:commandButton value="Update" reRender="input1"
 actionListener="#{testPage.update}"/>
 </a4j:form>
</body>
</html>

With the binding each click on update button invokes constructor, init and then update method. Without the binding only update is invoked.

[nbelaevski]

This happens because "binding" is evaluated before a4j:keepAlive, so new instance of bean is being created. I see the only solution - do not use binding for keep-alived beans.

[samvimes]

Ok. Thanx for your help.

So as far as I understand the expected behavior of a4j:keepAlive is that the bean instance exists until I leave the view or remove it programmatically (and the constructor is therefore only called once on page initialization)?

[ilya_shaikovsky]

yes, it's expected behavior. But it still not restored when binding tries to resolve the bean so it's created before as Nick said. We described this limitation a few time there. But seems it's still undocumented. So I will create a wiki for that.

https://jira.jboss.org/jira/browse/RFPL-214

Thanks!