Getting objects from conversation in a custom PhaseListener
I need to make a URL that can download a binary file based on information stored in a long running conversation. I can get it to work fine once from a page, but the second time, it fails with:
ERROR [PhaseListenerManager] Exception in PhaseListener RESTORE_VIEW(1) afterPhase java.lang.IllegalStateException: No active event context at org.jboss.seam.core.Manager.instance(Manager.java:267)
I'm pretty sure something I'm doing is ending the long running conversation, because if I just download a document once, then try to continue with my workflow by going to the next page, or even just refresh the current page, I get a similar error:
org.jboss.seam.NoConversationException: no long-running conversation for @Conversational bean
I'm pretty new at Seam, so if I'm making a colossal blunder, please be kind... :-) I've searched all over trying to figure out what is going on, but I just can't seem to find anything relevant.
Here is my PhaseListener:
package com.myco.myproj;
import java.util.Set;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
import javax.servlet.http.HttpServletResponse;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.security.Restrict;
import org.jboss.seam.contexts.EntityBean;
import org.jboss.seam.core.Manager;
import org.jboss.seam.jsf.TransactionalSeamPhaseListener;
import org.jboss.seam.log.Log;
@Name("docPhaseListener")
@Restrict("#{identity.loggedIn}")
@SuppressWarnings("serial")
public class DocPhaseListener extends TransactionalSeamPhaseListener {
public final static int BUF_SIZE = 16384;
public final static String DOC_VIEW_ID = "/document/";
private static Log log = (Log) org.jboss.seam.log.Logging.getLog(DocPhaseListener.class);
private MyObject getMyObject(FacesContext context) {
MyObject myObject = null;
log.info("Manager.instance().getCurrentConversationId()="+Manager.instance().getCurrentConversationId());
ValueBinding vb = context.getApplication().createValueBinding("#{myObject}");
if(vb == null) {
log.info("vb is null!");
} else {
Object o = null;
log.info("vb type="+vb.getType(context)+", vb value="+(o=vb.getValue(context)));
if(o instanceof MyObject)
myObject = (MyObject) o;
else
log.info("Not MyObject!");
}
return myObject;
}
public void afterPhase(PhaseEvent event) {
super.afterPhase(event);
FacesContext context = event.getFacesContext();
String viewId = context.getViewRoot().getViewId();
int index = viewId.indexOf(DOC_VIEW_ID);
if (PhaseId.RESTORE_VIEW.equals(event.getPhaseId()) && index != -1 && viewId.endsWith(".xhtml")) {
MyObject myObject = getMyObject(context);
if(myObject != null)
Util.handleDocumentRequest(context, myObject);
else {
// TODO: Handle bad requests better
((HttpServletResponse)context.getExternalContext().getResponse()).setContentType("application/octet-stream");
context.responseComplete();
}
}
}
}
Since I'm extending TransactionalSeamPhaseListener (it seems necessary to get into the conversation the first time), and you can't have more than one SeamPhaseListener, I had to replace the existing one with mine, so my faces-config.xml looks like this:
<lifecycle> <!--phase-listener>org.jboss.seam.jsf.TransactionalSeamPhaseListener</phase-listener--> <phase-listener>com.medorder.mazama.DocumentPhaseListener</phase-listener> </lifecycle>
My UI is part of a rich:dataTable, and the column looks like this:
<h:column>
<f:facet name="header">Download</f:facet>
<h:outputLink value="document/download.seam?cid=#{conversation.id}&clr=true">
<f:verbatim>Download</f:verbatim>
</h:outputLink>
</h:column>
Eventually, this URL will be called from an embedded Flash object, so I really need to use a PhaseListener. Can anyone tell me what I'm doing wrong to end the conversation?
I have also tried just implementing PhaseListener, and pulling the object from the SessionMap directly using the key "org.jboss.seam.CONVERSATION#xx$myObject", but I get the same kind of problem. The second time I access the EntityBean that is returned, the instance it points to is null.
Also, can someone confirm my suspicion that @Name and @Restrict are pointless to use on a PhaseListener? I don't think any injection has worked on it, and I'm pretty sure that it is not possible to use those on something that pretty much by definition lives outside the life-cycle.
