PrimeFaces Ajax ActionListener

It is used to call Java method by triggering action. This action can be done either by using commandButton or commandLink. Here, we are creating and example that call a method of ManagedBean and each time the button is clicked the current value is updated with Ajax.

This example includes the following files.

JSF File

// actionListener.xhtml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://xmlns.jcp.org/jsf/html"
xmlns:p="http://primefaces.org/ui">
<h:head>
<title>actionListener</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
</h:head>
<h:body>
<h2>ActionListener Example</h2>
<h:form>
<h:panelGrid columns="2" cellpadding="5">
<h:outputText value="Counter: " />
<h:outputText id="output" value="#{ajaxCounter.counter}" />
</h:panelGrid><br/>
<p:commandButton value="Count" actionListener="#{ajaxCounter.increment()}" update="output" />
</h:form>
</h:body>
</html>

Managed Bean

// AjaxCounter.java

package com.javatpoint;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
@ManagedBean
@ViewScoped
public class AjaxCounter {
int counter;
public int getCounter() {
return counter;
}
public void setCounter(int counter) {
this.counter = counter;
}
public void increment(){
counter+=2;
}
}

Output: