File-upload with multiple files fails in Primefaces 5.1 - jsf

Question

I try to do a file upload in primefaces with PF 5.1 and OmniFaces version 1.7.
My .xhtml code:
<h:form id="fileImportForm" styleClass="prepend-top"
prependId="false">
<div style='margin-bottom:10px'>
<h:outputLabel value="#{msg.file_import_msg}"/>
</div>
<p:fileUpload id="fileImport" fileUploadListener="#{fileImport.handleFileUpload}"
mode="advanced"
update="messages"
multiple="true"
label="#{msg.file_import_choose_label}"
uploadLabel="#{msg.file_import_upload_label}"
cancelLabel="#{msg.file_import_cancel_label}"
/>
<p:growl id="messages" showDetail="true"/>
</h:form>
My backing bean:
package test.boundary;
import javax.inject.Named;
import org.primefaces.event.FileUploadEvent;
import com.haslerrail.aura.common.exception.SystemException;
/**
* BackingBean for <code>fileImport.xhtml</code> page.
*
*/
#Named
public class FileImport implements java.io.Serializable {
private static final long serialVersionUID = 1L;
public void handleFileUpload(final FileUploadEvent event) throws SystemException, InterruptedException {
if (event == null || event.getFile() == null || event.getFile().getSize() == 0) {
System.out.println("No file");
}
System.out.println(event.getFile().getFileName());
Thread.sleep(500); // wait a little to force the exception!
}
}
The problem is, when my handleFileUpload function takes a little bit longer to parse the uploaded file (Thread.sleep(500), it throws an exception! The exception only occurs when I'm uploading more than one file at the same time.
The exception:
09:47:33,171 WARN [org.jboss.weld.Conversation] WELD-000315 Failed to acquire conversation lock in 1,000 for Conversation with id: 1
09:47:33,180 SEVERE [org.omnifaces.exceptionhandler.FullAjaxExceptionHandler] FullAjaxExceptionHandler: An exception occurred during processing JSF ajax request. Error page '/pages/error/error.xhtml' will be shown.: org.jboss.weld.context.BusyConversationException: WELD-000322 Conversation lock timed out: 1
at org.jboss.weld.context.AbstractConversationContext.activate(AbstractConversationContext.java:215) [weld-core-1.1.5.AS71.Final.jar:2012-02-10 15:31]
at org.jboss.weld.jsf.WeldPhaseListener.activateConversations(WeldPhaseListener.java:108) [weld-core-1.1.5.AS71.Final.jar:2012-02-10 15:31]
at org.jboss.weld.jsf.WeldPhaseListener.beforePhase(WeldPhaseListener.java:85) [weld-core-1.1.5.AS71.Final.jar:2012-02-10 15:31]
at com.sun.faces.lifecycle.Phase.handleBeforePhase(Phase.java:228) [jsf-impl-2.1.7-jbossorg-2.jar:]
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:99) [jsf-impl-2.1.7-jbossorg-2.jar:]
at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:116) [jsf-impl-2.1.7-jbossorg-2.jar:]
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) [jsf-impl-2.1.7-jbossorg-2.jar:]
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:102) [primefaces-5.1.jar:5.1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.jboss.weld.servlet.ConversationPropagationFilter.doFilter(ConversationPropagationFilter.java:62) [weld-core-1.1.5.AS71.Final.jar:2012-02-10 15:31]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.omnifaces.filter.CacheControlFilter.doFilter(CacheControlFilter.java:226) [omnifaces-1.7.jar:1.7]
at org.omnifaces.filter.HttpFilter.doFilter(HttpFilter.java:77) [omnifaces-1.7.jar:1.7]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:489) [jbossweb-7.0.13.Final.jar:]
at org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50) [jboss-as-jpa-7.1.1.Final.jar:7.1.1.Final]
at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153) [jboss-as-web-7.1.1.Final.jar:7.1.1.Final]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368) [jbossweb-7.0.13.Final.jar:]
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [jbossweb-7.0.13.Final.jar:]
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671) [jbossweb-7.0.13.Final.jar:]
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930) [jbossweb-7.0.13.Final.jar:]
at java.lang.Thread.run(Thread.java:745) [rt.jar:1.7.0_75]
For me it looks like an error in PF 5.1! Any other ideas?

Answer 1

p:fileUpload multiple="true" uploads each file in its own request. Problem is, the requests happen simultaneously, which in your case triggers conversation lock timeout, since each request tries to access the same conversation. Another problem is that JSF actually requires client-side code to send requests sequentially, and its server-side code is not thread-safe.
I advise making the upload requests happen sequentially. There are multiple ways to achieve this.
PrimeFaces 5.2.6 and above: you should be able to just use the sequential attribute:
<p:fileUpload sequential="true" ...
(The attribute was implemented in PF Issue #403.)
This answer suggests a way via Javascript, by configuring the jQuery File Upload Plugin, which PrimeFaces uses.
Add a Weld dependency. Then you could change the default lock timeout (in a non-portable CDI way), so the requests form a queue on the server. The default lock timeout is 1 second. The following code changes lock timeout globally for all conversations.
import javax.enterprise.context.ConversationScoped;
import javax.enterprise.context.Initialized;
import javax.enterprise.event.Observes;
import javax.inject.Inject;
import javax.servlet.ServletRequest;
import org.jboss.weld.context.http.HttpConversationContext;
public class ConversationTimeoutDefaultSetter {
#Inject
private HttpConversationContext ctx;
public void conversationInitialized(
#Observes #Initialized(ConversationScoped.class)
ServletRequest payload) {
ctx.setConcurrentAccessTimeout(10000L); // 10 seconds
}
}
Update: I forgot, that Initialized requires CDI 1.1, and you seem to be using 1.0. You can set the timeout when you're beginning your conversation.