Question

I have a check box in my application and I want to call selectPlan method to execute when user select the check box

But when ever I select the check box it call the @PostConstruct method before the selectPlan method.

This leads to unwanted calls to back end as I have written some functions to populate data when page load in the @PostConstruct

<td>
      <h:selectBooleanCheckbox value="#{plan.checked}">
         <f:ajax listener="#{planOverlay.selectPlan}" render=":overlayForm:myTable"/>
      </h:selectBooleanCheckbox>
</td>

Below is the bean class

 import javax.faces.bean.ManagedBean;
 import javax.faces.bean.ViewScoped;

 @ManagedBean(name = "planOverlay")
 @ViewScoped
 public class PlanOverlayBean extends OverlayBean {

    @PostConstruct
    public void init() {
       super.init();

       loadPlansFrom_DB();
    }

    public void selectPlan(AjaxBehaviorEvent event) throws Exception {
       getOverlay().getService().setSelectedPlan(rowdata);
    }
}

Answer 1

To avoid that case,we should check if it is postback or ajaxRequest. If your bean is viewScoped,you can add below code to your post-construct method.

Maybe it is not the best case but it works.

Also you can use JSF 2 PreRenderViewEvent for some initialization for bean.

    if (!FacesContext.getCurrentInstance().isPostback()) {
            if (!FacesContext.getCurrentInstance().getPartialViewContext().isAjaxRequest()) {
       //Some initialization  
        } 
}

Answer 2

You should make your bean session scoped, so the @PostConstruct gets called only once per session. When bean is request scoped, like yours is judging by the behavior, it is created for each request which results in init() getting called also for each request.

EDIT

The suggestion was based on the assumption that the bean is request scoped, and that init() should be called once per session/view. OP's comment proved the assumption wrong.