6
'da özel bir etiket işleyicisi uygularken, aşağıdaki etiket işleyici sınıfı verildi.java.lang.IllegalStateException: java.lang.InstantiationException, JSF
public final class ViewParamValidationFailed extends TagHandler implements ComponentSystemEventListener
{
private final String redirect;
public ViewParamValidationFailed(TagConfig config) {
super(config);
redirect = getRequiredAttribute("redirect").getValue();
}
@Override
public void apply(FaceletContext context, UIComponent parent) throws IOException {
if (parent instanceof UIViewRoot && !context.getFacesContext().isPostback()) {
((UIViewRoot) parent).subscribeToEvent(PostValidateEvent.class, this);
}
}
@Override
public void processEvent(ComponentSystemEvent event) throws AbortProcessingException {
FacesContext context = FacesContext.getCurrentInstance();
if (context.isValidationFailed()) {
try {
ExternalContext externalContext = context.getExternalContext();
externalContext.redirect(externalContext.getRequestContextPath() + redirect);
}
catch (IOException e) {
throw new AbortProcessingException(e);
}
}
}
}
Etiket işleyicisi, dönüştürme başarısız olduğunda yalnızca bir sayfaya yönlendirmek içindir.
Bu, bir XHTML sayfasında aşağıdaki gibi kullanılır.
<?xml version='1.0' encoding='UTF-8' ?>
<!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:h="http://xmlns.jcp.org/jsf/html"
xmlns:p="http://primefaces.org/ui"
xmlns:my="http://example.com/ui"
xmlns:f="http://xmlns.jcp.org/jsf/core">
<h:head>
<title>Test</title>
</h:head>
<h:body>
<f:metadata>
<f:viewParam name="id" required="true" value="#{testManagedBean.id}"/>
<my:viewParamValidationFailed redirect="/public_resources/PageNotFound.jsf"/>
</f:metadata>
<h:form id="form" prependId="true">
<p:commandButton value="Submit" actionListener="#{testManagedBean.submitAction}"/>
</h:form>
</h:body>
</html>
biz <f:metadata><ui:define name="metaData"> içine kapatılmış olduğu bir şablon var <f:viewParam> sadece Gerçekte
converter="javax.faces.Long" gibi isteğe bağlı bir dönüştürücü özelliği olabilir. Verilen <p:commandButton> basıldığında
@ManagedBean
@RequestScoped
public final class TestManagedBean
{
private Long id; // Getter and setter.
public TestManagedBean() {}
public void submitAction() {
System.out.println("submitAction() called.");
}
}
aşağıdaki istisnası atılır:
ilişkili JSF fasulye başardı.
SEVERE: java.lang.IllegalStateException: java.lang.InstantiationException: tags.ViewParamValidationFailed
at javax.faces.component.StateHolderSaver.restore(StateHolderSaver.java:153)
at javax.faces.component.UIComponent$ComponentSystemEventListenerAdapter.restoreState(UIComponent.java:2633)
at javax.faces.component.StateHolderSaver.restore(StateHolderSaver.java:165)
at javax.faces.component.UIComponentBase.restoreAttachedState(UIComponentBase.java:1793)
at javax.faces.component.UIComponentBase.restoreSystemEventListeners(UIComponentBase.java:1911)
at javax.faces.component.UIComponentBase.restoreState(UIComponentBase.java:1607)
at javax.faces.component.UIViewRoot.restoreState(UIViewRoot.java:1771)
at com.sun.faces.application.view.FaceletPartialStateManagementStrategy$2.visit(FaceletPartialStateManagementStrategy.java:380)
at com.sun.faces.component.visit.FullVisitContext.invokeVisitCallback(FullVisitContext.java:151)
at javax.faces.component.UIComponent.visitTree(UIComponent.java:1690)
at com.sun.faces.application.view.FaceletPartialStateManagementStrategy.restoreView(FaceletPartialStateManagementStrategy.java:367)
at com.sun.faces.application.StateManagerImpl.restoreView(StateManagerImpl.java:138)
at com.sun.faces.application.view.ViewHandlingStrategy.restoreView(ViewHandlingStrategy.java:123)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.restoreView(FaceletViewHandlingStrategy.java:590)
at com.sun.faces.application.view.MultiViewHandler.restoreView(MultiViewHandler.java:150)
at javax.faces.application.ViewHandlerWrapper.restoreView(ViewHandlerWrapper.java:353)
at org.omnifaces.viewhandler.RestorableViewHandler.restoreView(RestorableViewHandler.java:66)
at javax.faces.application.ViewHandlerWrapper.restoreView(ViewHandlerWrapper.java:353)
at com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:197)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:121)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:70)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.InstantiationException: tags.ViewParamValidationFailed
at java.lang.Class.newInstance0(Class.java:357)
at java.lang.Class.newInstance(Class.java:325)
at javax.faces.component.StateHolderSaver.restore(StateHolderSaver.java:150)
... 54 more
Bu etiket işleyici yalnızca <f:viewParam> ile ilişkili olmalıdır ve tamamen geri sonrası yapıldığında, örneğin içinde atlandı.
Herhangi bir çözüm var mı? Önemli
: apply() yöntemi içinde koşullu kontroller sırasında
,
verilen butonuna tıklandığındaif (parent instanceof UIViewRoot && !context.getFacesContext().isPostback()) {
System.out.println("Inside if");
((UIViewRoot) parent).subscribeToEvent(PostValidateEvent.class, this);
}
, bu durum bariz olarak false değerlendirilir. Bu nedenle, herhangi bir sorun olmamalıdır.
Şaşırtıcı bir şekilde, istisna if ifadesindeki tek satır aşağıdaki gibi kaldırıldığında istisna kaybolur.
if (parent instanceof UIViewRoot && !context.getFacesContext().isPostback()) {
//Debug statements only.
}
Bu koşul yanlış olarak değerlendirilir olsa verilen <p:commandButton> bu durumda basıldığında, yukarıda belirtildiği gibi istisna değildir.