在f：ajax侦听器方法中，由h：selectOneMenu设置的值为null

Question

I'm trying to use AJAX in my JSF 2.0 web application and have a problem with getting current value from selectOneMenu.

Part of my JSF page.

<h:panelGrid columns="2">
<h:outputLabel value="Appendix number" for="appendix" />
<h:selectOneMenu id="appendix" value="#{indexMBean.appendix}">
<f:selectItem itemLabel="Point 1" itemValue="1" />
<f:selectItem itemLabel="Point 2" itemValue="2" />
<f:ajax event="change" listener="#{indexMBean.setHazardsByAppendix}" />
</h:selectOneMenu>
</h:panelGrid>

setHazardsByAppendix is a procedure in indexMBean. Then the procedure fires I try to get the current value of h:selectOneMenu for passing it on another procedure.

public void setHazardsByAppendix() {
    Logger logger = Logger.getAnonymousLogger();
    logger.warning(this.appendix);
    this.setHazards(this.hazardSessionBean.getHazardByAppendix(this.appendix));
}

But the current value of field appendix is always null. How is this caused and how can I solve it?

Answer 1

Solved in a very strange way. I created a new netbeans project with the same sources. And amazingly it works fine. It's a really strange but it works.

Answer 2

   `<f:ajax execute="@this" listener="#{templateSearchHandler.OnDefNameSelect}">
 void setHazardsByAppendix(AjaxBehaviorEvent event) {
    Logger logger = Logger.getAnonymousLogger();
    logger.warning(this.appendix);
    this.setHazards(this.hazardSessionBean.getHazardByAppendix(this.appendix));
}`

Answer 3

This code calls AjaxBehaviour event and pass value to controller through Ajax.

<h:panelGrid columns="2">
<h:outputLabel value="Appendix number" for="appendix" />
<h:selectOneMenu id="appendix" value="#{indexMBean.appendix}">
<f:selectItem itemLabel="Point 1" itemValue="1" />
<f:selectItem itemLabel="Point 2" itemValue="2" />
<f:ajax execute="@this"listener="#{indexMBean.setHazardsByAppendix}" />
</h:selectOneMenu>
</h:panelGrid>
//Controller
public void setHazardsByAppendix(AjaxBehaviorEvent event) {
    Logger logger = Logger.getAnonymousLogger();
    logger.warning(this.appendix);
    this.setHazards(this.hazardSessionBean.getHazardByAppendix(this.appendix));
}