我有带有标准JSF异常处理的JSF 2.3 WAR项目。请求中的任何错误都将分派到在web.xml中配置的jsf错误页面。我还使用新的JSF 2.3 improved CDI support注入FacesContext。
问题是当序数页面上出现一些未处理的错误，并且jsf将请求分派到错误页面时。然后我在IllegalStateException中得到一个com.sun.faces.context.FacesContextImpl.assertNotReleased。
经过一些调试后，我意识到问题出在我在两个视图中注入FacesContext时。这种情况下的关键问题是，FacesContext的注入存储在Request Scope中，并且在错误页面上再次注入时，存储在Request范围中的FacesContext已被释放并且已废弃，因为在以下情况下再次创建错误页面已创建。
为了显示这种情况，我制作了一个在WildFly 16.0.0.Final上运行的小型演示项目，其页面简单index.xhtml：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://xmlns.jcp.org/jsf/html">
<body>
<p>
<h:outputText value="Index page"/>
</p>
<p>
<h:outputText value="Is postback: #{facesContext.postback}"/>
<h:outputText value="#{index.throwException()}"/>
</p>
</body>
</html>
和error.xhtml：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://xmlns.jcp.org/jsf/html">
<body>
<h:outputText value="Error page"/>
<h:outputText value="Is postback: #{facesContext.postback}"/>
</body>
</html>
我的web.xml是：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.jsf</url-pattern>
</servlet-mapping>
<error-page>
<exception-type>java.lang.Throwable</exception-type>
<location>/error.jsf</location>
</error-page>
<default-context-path>/</default-context-path>
<welcome-file-list>
<welcome-file>index.jsf</welcome-file>
</welcome-file-list>
</web-app>
尝试显示index.jsf后，出现以下异常：
14:26:12,688 ERROR [io.undertow.request] (default task-1) UT005022: Exception generating error page /error.jsf: javax.servlet.ServletException
at javax.faces.api@2.3.9.SP01//javax.faces.webapp.FacesServlet.executeLifecyle(FacesServlet.java:725)
at javax.faces.api@2.3.9.SP01//javax.faces.webapp.FacesServlet.service(FacesServlet.java:451)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:81)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at io.undertow.core@2.0.19.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.core@2.0.19.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.core@2.0.19.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:274)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler.dispatchToPath(ServletInitialHandler.java:209)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.spec.RequestDispatcherImpl.error(RequestDispatcherImpl.java:502)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.spec.RequestDispatcherImpl.error(RequestDispatcherImpl.java:428)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:331)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
at org.wildfly.extension.undertow@16.0.0.Final//org.wildfly.extension.undertow.security.SecurityContextThreadSetupAction.lambda$create$0(SecurityContextThreadSetupAction.java:105)
at org.wildfly.extension.undertow@16.0.0.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502)
at org.wildfly.extension.undertow@16.0.0.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502)
at org.wildfly.extension.undertow@16.0.0.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502)
at org.wildfly.extension.undertow@16.0.0.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1502)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
at io.undertow.servlet@2.0.19.Final//io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104)
at io.undertow.core@2.0.19.Final//io.undertow.server.Connectors.executeRootHandler(Connectors.java:364)
at io.undertow.core@2.0.19.Final//io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830)
at org.jboss.threads@2.3.3.Final//org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1982)
at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486)
at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377)
at java.base/java.lang.Thread.run(Thread.java:835)
Caused by: java.lang.IllegalStateException
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.context.FacesContextImpl.assertNotReleased(FacesContextImpl.java:692)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.context.FacesContextImpl.isPostback(FacesContextImpl.java:185)
at jdk.internal.reflect.GeneratedMethodAccessor29.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at javax.el.api@1.0.13.Final//javax.el.BeanELResolver.getValue(BeanELResolver.java:241)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:156)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:184)
at org.glassfish.javax.el@3.0.1-b08-jbossorg-1//com.sun.el.parser.AstValue.getValue(AstValue.java:139)
at org.glassfish.javax.el@3.0.1-b08-jbossorg-1//com.sun.el.parser.AstValue.getValue(AstValue.java:203)
at org.glassfish.javax.el@3.0.1-b08-jbossorg-1//com.sun.el.parser.AstDeferredExpression.getValue(AstDeferredExpression.java:63)
at org.glassfish.javax.el@3.0.1-b08-jbossorg-1//com.sun.el.parser.AstCompositeExpression.getValue(AstCompositeExpression.java:68)
at org.glassfish.javax.el@3.0.1-b08-jbossorg-1//com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:226)
at org.jboss.weld.core@3.1.0.Final//org.jboss.weld.module.web.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
at org.jboss.weld.core@3.1.0.Final//org.jboss.weld.module.web.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:73)
at javax.faces.api@2.3.9.SP01//javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:170)
at javax.faces.api@2.3.9.SP01//javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:157)
at javax.faces.api@2.3.9.SP01//javax.faces.component.UIOutput.getValue(UIOutput.java:140)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:181)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:328)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:143)
at javax.faces.api@2.3.9.SP01//javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:595)
at javax.faces.api@2.3.9.SP01//javax.faces.component.UIComponent.encodeAll(UIComponent.java:1654)
at javax.faces.api@2.3.9.SP01//javax.faces.component.UIComponent.encodeAll(UIComponent.java:1650)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:468)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:170)
at javax.faces.api@2.3.9.SP01//javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
at javax.faces.api@2.3.9.SP01//javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:132)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:102)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.lifecycle.Phase.doPhase(Phase.java:76)
at com.sun.jsf-impl@2.3.9.SP01//com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:199)
at javax.faces.api@2.3.9.SP01//javax.faces.webapp.FacesServlet.executeLifecyle(FacesServlet.java:708)
... 34 more
最后，我不确定这是JSF错误还是由设计造成的，我应该以其他方式使用它吗？