EventBusFactory JSF1073

Question

I'm trying to implement logic in JSF that accepts parameters and then updates some output on the xhtml page. The following is all borrowed from the primefaces pushdata showcase

XHTML:

<f:view>
                <h:form id="form">
                    <f:metadata>
                        <f:viewParam name="data" value="#{viewParamPush.data}" />
                        <f:event type="preRenderView" listener="#{viewParamPush.prerender}" />
                    </f:metadata>

                    <h:outputText id="out" value="#{viewParamPush.data}" style="font-size:16px" />

                    <p:socket onMessage="handleMessage" channel="/QR" />

                    <script type="text/javascript">
                        function handleMessage(data) {
                            $('#out').text(data);
                        }
                    </script>
                </h:form>
            </f:view>

ViewParamPush:

    ManagedBean
    @RequestScoped
    public class ViewParamPush implements Serializable{

        private String data;

        public String getData() {
            return data;
        }

        public void setData(String data) {
            util.sysprint("setData " + data, true);
            this.data = data;
        }

        public void prerender() {
            util.sysprint("prerender", true);
            EventBus eventBus = EventBusFactory.getDefault().eventBus();
            util.sysprint("prerender2", true);
            even

tBus.publish("/QR", data);
        util.sysprint("prerender3", true);
    }
}

ViewParamResource:

@PushEndpoint("/QR")
public class ViewParamResource {

    @OnMessage(encoders = {JSONEncoder.class})
    public String onMessage(String data) {
         util.sysprint("ViewParamResource onMessage", true);
        return StringEscapeUtils.escapeHtml4(data);
    }
}

I get the following exception when eventBus.publish("/QR", data); is called. I understand what a null pointer is however I don't understand why publish("/QR", data); in this case is causing one. Is there something wrong with my syntax?

FATAL:   JSF1073: javax.el.ELException caught during processing of RENDER_RESPONSE 6 : UIComponent-ClientId=, Message=/QR.xhtml @21,95 listener="#{viewParamPush.prerender}": java.lang.NullPointerException
FATAL:   /QR.xhtml @21,95 listener="#{viewParamPush.prerender}": java.lang.NullPointerException
javax.el.ELException: /QR.xhtml @21,95 listener="#{viewParamPush.prerender}": java.lang.NullPointerException 

I added *.xhtml to the url patterns in order to be able to call the script QR.xhtml?data=some data.. I assume that required in order to pass parameters to the script although I wonder if that affects the publish method

<servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>/faces/*</url-pattern>
        **<url-pattern>*.xhtml</url-pattern>**
    </servlet-mapping>

Dependencies:

 <dependencies>
        <dependency>
            <groupId>org.primefaces</groupId>
            <artifactId>primefaces</artifactId>
            <version>5.3</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.extras</groupId>
            <artifactId>appserv-rt</artifactId>
            <version>3.1.1</version>
        </dependency>
        <!-- http://mvnrepository.com/artifact/org.atmosphere/atmosphere-runtime -->
        <dependency>
            <groupId>org.atmosphere</groupId>
            <artifactId>atmosphere-runtime</artifactId>
            <version>2.4.4</version>
        </dependency>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-web-api</artifactId>
            <version>7.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.marklogic</groupId>
            <artifactId>java-client-api</artifactId>
            <version>3.0.1</version>
        </dependency>
        <dependency>  
            <groupId>org.primefaces.themes</groupId>  
            <artifactId>cupertino</artifactId>  
            <version>1.0.10</version>  
        </dependency>
        <dependency>
            <groupId>org.primefaces.extensions</groupId>
            <artifactId>primefaces-extensions</artifactId>
            <version>4.0.0</version>
        </dependency>
        <dependency>
            <groupId>com.helger</groupId>
            <artifactId>ph-schematron</artifactId>
            <version>3.0.1</version>
        </dependency>
        <dependency>
            <groupId>com.lowagie</groupId>
            <artifactId>itext</artifactId>
            <version>2.1.7</version>
            <exclusions>
                <exclusion>
                    <groupId>bouncycastle</groupId>
                    <artifactId>bcprov-jdk14</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>bouncycastle</groupId>
                    <artifactId>bcmail-jdk14</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.bouncycastle</groupId>
                    <artifactId>bctsp-jdk14</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.9</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.9</version>
        </dependency>
        <dependency>
            <groupId>net.sf.barcode4j</groupId>
            <artifactId>barcode4j-light</artifactId>
            <version>2.1</version>
        </dependency>
        <dependency>
            <groupId>net.glxn</groupId>
            <artifactId>qrgen</artifactId>  <!-- QR code support -->
            <version>1.4</version>
        </dependency>
    </dependencies>

Answer 1

I've previously encountered this error. The reason for this failure is due to the Atmosphere version.

Then use it as below :

pom.xml

     <dependency>
        <groupId>org.atmosphere</groupId>
        <artifactId>atmosphere-runtime</artifactId>
        <version>2.4.3</version>
    </dependency>
    <dependency>
        <groupId>org.atmosphere</groupId>
        <artifactId>atmosphere-runtime-native</artifactId>
        <version>2.4.3</version>
    </dependency>

web.xml

<servlet>
    <servlet-name>Push Servlet</servlet-name>
    <servlet-class>org.primefaces.push.PushServlet</servlet-class>
    <init-param>
        <param-name>org.atmosphere.cpr.broadcasterCacheClass</param-name>
        <param-value>org.atmosphere.cache.UUIDBroadcasterCache</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <async-supported>true</async-supported>
</servlet>
<servlet-mapping> 
    <servlet-name>Push Servlet</servlet-name> 
    <url-pattern>/primepush/*</url-pattern> 
</servlet-mapping>

This way you can try. It works this for me.