Server Push using Prime Push with Tomcat

Server Push is described as a mechanism in which the server initiates a transaction to a client. This mechanism has various interesting implementations which improve the options for interaction on a website such as counter.
There are various technologies which implement mechanisms to achieve the experience of server push such as

• Native Comet (The WebServer has API for Comet)
• Native WebSockets (The WebServer has API for WebSocket)
• WebSockets
• Long-Polling
• Http Streaming
• JSONP
• Server-Sent Events

All these technologies are supported in the Prime Push using Atmosphere Framework.
While implementing prime push using Web Sockets, I came across an issues with Tomcat that it is not behaving as required. After long search on Google I found that we need to open socket connection on Tomcat by replacing HTTP 1.1 protocol with org.apache.coyote.http11.Http11NioProtocol of connector in the server.xml file.

Server.xml Configuration

<Connector connectionTimeout="20000" port="8080" protocol="org.apache.coyote.http11.Http11NioProtocol" redirectPort="8443"/>

view raw Server.xml hosted with ❤ by GitHub

Implementation

Web.xml Configuration

	<servlet>
	<servlet-name>Push Servlet</servlet-name>
	<servlet-class>org.primefaces.push.PushServlet</servlet-class>
	<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
	<servlet-name>Push Servlet</servlet-name>
	<url-pattern>/primepush/*</url-pattern>
	</servlet-mapping>
	...
	...
	</servlet>

view raw Web.xml hosted with ❤ by GitHub

Maven Dependencies

	<dependency>
	<groupId>org.primefaces</groupId>
	<artifactId>primefaces</artifactId>
	<version>4.0</version>
	</dependency>
	<dependency>
	<groupId>com.google.code.gson</groupId>
	<artifactId>gson</artifactId>
	<version>2.2.4</version>
	</dependency>
	<dependency>
	<groupId>org.atmosphere</groupId>
	<artifactId>atmosphere-runtime</artifactId>
	<version>2.0.3</version>
	</dependency>
	<dependency>
	<groupId>org.apache.commons</groupId>
	<artifactId>commons-lang3</artifactId>
	<version>3.1</version>
	</dependency>
	<dependency>
	<groupId>commons-lang</groupId>
	<artifactId>commons-lang</artifactId>
	<version>2.6</version>
	</dependency>
	<dependency>
	<groupId>com.sun.faces</groupId>
	<artifactId>jsf-api</artifactId>
	<version>2.2.4</version>
	</dependency>
	<dependency>
	<groupId>com.sun.faces</groupId>
	<artifactId>jsf-impl</artifactId>
	<version>2.2.4</version>
	</dependency>

view raw pom.xml hosted with ❤ by GitHub

Counter Bean

	package com.envista.publicweb;
	import java.io.Serializable;
	import javax.faces.bean.ManagedBean;
	import javax.faces.bean.ViewScoped;
	import org.primefaces.push.PushContext;
	import org.primefaces.push.PushContextFactory;
	@SuppressWarnings("serial")
	@ManagedBean(name = "globalCounter")
	@ViewScoped
	public class GlobalCounterBean implements Serializable {
	private int count;
	public int getCount() {
	return count;
	}
	public void setCount(int count) {
	this.count = count;
	}
	public synchronized void increment() {
	count++;
	PushContext pushContext = PushContextFactory.getDefault().getPushContext();
	pushContext.push("/counter", String.valueOf(count));
	}
	}

view raw GlobalCounterBean.java hosted with ❤ by GitHub

Page.xhtml

	<?xml version="1.0" encoding="UTF-8"?>
	<ui:composition
	xmlns="http://www.w3.org/1999/xhtml"
	xmlns:ui="http://java.sun.com/jsf/facelets"
	xmlns:h="http://java.sun.com/jsf/html"
	xmlns:p="http://primefaces.org/ui"
	xmlns:f="http://java.sun.com/jsf/core" template="/template.xhtml">
	<ui:define name="head">
	<style type="text/css">
	.display {
	font-size: 36px !important;
	}
	</style>
	<script type="text/javascript">
	//
	<![CDATA[
	function handleMessage(data) {
	$('.display').html(data);
	}
	//]]>
	</script>
	</ui:define>
	<ui:define name="content">
	<h:form>
	<h:outputText value="#{globalCounter.count}" styleClass="ui-widget display" />
	<br />
	<p:commandButton value="Click" actionListener="#{globalCounter.increment}" />
	</h:form>
	<p:socket onMessage="handleMessage" channel="/counter" />
	</ui:define>
	</ui:composition>

view raw Page.xhtml hosted with ❤ by GitHub