primefaces p:commandButton does not call the method from bean

Question

I have a button that calls a method from bean. But it does not call the method. I have other buttons in other pages, they all work fine but in this page i have a problem and dont know why.

the ui code :

<h:form>

    <p:commandButton value="#{label.save}" actionListener="#{encoderBean.saveEncoder}" styleClass="ui-priority-primary" /> 

</h:form>

the bean code :

public void saveEncoder() {
    System.out.println("Save Encoder");
 }

thanks in advance. By the way, i have tried all the things in stack overflow but they all did not work out.