Understanding the JSF life cycle is very important for understanding how JSF works. It’s also very useful for debugging. For example, if you pass phases 1-3 and then jump to phase 6, this usually means there were conversion/validation errors. Knowing what phases were passed, you need to create a simple phase listener. Here is the super quick way to create a phase tracker.
First, creating the actual phase listener:
package lifecycle;
import javax.faces.context.FacesContext;
import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
public class PhaseTracker implements
javax.faces.event.PhaseListener {
public void afterPhase(PhaseEvent event) {
FacesContext.getCurrentInstance().getExternalContext().log("AFTER - "+
event.getPhaseId());
}
public void beforePhase(PhaseEvent event) {
FacesContext.getCurrentInstance().getExternalContext().log("BEFORE - "+
event.getPhaseId());
}
public PhaseId getPhaseId() {
return PhaseId.ANY_PHASE;
}
}
Second and the last step is to register the listener in JSF configuration file:
lifecycle.PhaseTracker
That’s it. Restart the server and look for addition output in the console. It should look like this:
INFO: BEFORE - RESTORE_VIEW 1 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: AFTER - RESTORE_VIEW 1 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: BEFORE - APPLY_REQUEST_VALUES 2 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: AFTER - APPLY_REQUEST_VALUES 2 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: BEFORE - PROCESS_VALIDATIONS 3 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: AFTER - PROCESS_VALIDATIONS 3 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: BEFORE - UPDATE_MODEL_VALUES 4 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: AFTER - UPDATE_MODEL_VALUES 4 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: BEFORE - INVOKE_APPLICATION 5 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: AFTER - INVOKE_APPLICATION 5 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: BEFORE - RENDER_RESPONSE 6 Jul 29, 2008 10:15:30 AM org.apache.catalina.core.ApplicationContext log INFO: AFTER - RENDER_RESPONSE 6
