Take a simple CDI (it could also be a JSF managed bean) bean as follows.
import java.io.Serializable;
import javax.inject.Named;
import javax.faces.view.ViewScoped;
@Named
@ViewScoped
public class TestManagedBean implements Serializable
{
private static final long serialVersionUID=1L;
public TestManagedBean() {}
}
If this bean is accessed by an XHTML page with a query-string parameter named cid which is needed for a @ConversationScoped CDI managed bean (which may accidently/deliberately be appended by end-users too), an exception looking something like the following is thrown.
Severe: Error Rendering View[/Test.xhtml]
org.jboss.weld.context.NonexistentConversationException: WELD-000321: No conversation found to restore for id 1
at org.jboss.weld.context.AbstractConversationContext.initialize(AbstractConversationContext.java:259)
at org.jboss.weld.context.http.LazyHttpConversationContextImpl.initialize(LazyHttpConversationContextImpl.java:68)
at org.jboss.weld.context.http.LazyHttpConversationContextImpl.checkContextInitialized(LazyHttpConversationContextImpl.java:93)
at org.jboss.weld.context.AbstractConversationContext.getCurrentConversation(AbstractConversationContext.java:445)
at org.jboss.weld.jsf.ConversationAwareViewHandler.getActionURL(ConversationAwareViewHandler.java:111)
at com.sun.faces.renderkit.html_basic.FormRenderer.getActionStr(FormRenderer.java:250)
at com.sun.faces.renderkit.html_basic.FormRenderer.encodeBegin(FormRenderer.java:143)
at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
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:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
Warning: StandardWrapperValve[Faces Servlet]: Servlet.service() for servlet Faces Servlet threw exception
org.jboss.weld.context.NonexistentConversationException: WELD-000321: No conversation found to restore for id 1
at org.jboss.weld.context.AbstractConversationContext.initialize(AbstractConversationContext.java:259)
at org.jboss.weld.context.http.LazyHttpConversationContextImpl.initialize(LazyHttpConversationContextImpl.java:68)
at org.jboss.weld.context.http.LazyHttpConversationContextImpl.checkContextInitialized(LazyHttpConversationContextImpl.java:93)
at org.jboss.weld.context.AbstractConversationContext.getCurrentConversation(AbstractConversationContext.java:445)
at org.jboss.weld.jsf.ConversationAwareViewHandler.getActionURL(ConversationAwareViewHandler.java:111)
at com.sun.faces.renderkit.html_basic.FormRenderer.getActionStr(FormRenderer.java:250)
at com.sun.faces.renderkit.html_basic.FormRenderer.encodeBegin(FormRenderer.java:143)
at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1854)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
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:415)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
at java.lang.Thread.run(Thread.java:745)
Can this exception be avoided anyway even though a parameter named cid is appended to the URL?
This is specific to Weld (the implementation), not to CDI (the API). There's in the current Weld 2.2.x version no simple nor native way to disable it. Weld however allows you changing the request parameter name cid to something else via HttpConversationContext#setParameterName(). You could set it to e.g. an java.util.UUID value during application's startup.
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ApplicationScoped;
import org.jboss.weld.context.http.HttpConversationContext;
@ManagedBean(eager=true)
@ApplicationScoped
public class Application {
@Inject
private HttpConversationContext conversationContext;
@PostConstruct
public void init() {
hideConversationScope();
}
/**
* "Hide" conversation scope by replacing its default "cid" parameter name
* by something unpredictable.
*/
private void hideConversationScope() {
conversationContext.setParameterName(UUID.randomUUID().toString());
}
}
Unfortunately, CDI doesn't have any equivalent for eager=true. Alternative is, if you've EJB at hands:
import javax.ejb.Startup;
import javax.ejb.Singleton;
@Startup
@Singleton
public class Application {
(you might want to add @TransactionAttribute(NOT_SUPPORTED) to turn off unnecessary DB transaction management around it)
Or, if you've OmniFaces at hands:
import org.omnifaces.cdi.Startup;
@Startup
public class Application {