Wednesday, September 17, 2014

Embedding a XMPP server inside your JSF Web Application using Vysper, TomEE and PrimeFaces

I have an application that needs to notify the user when some job is done. It uses JSF and Primefaces, so this sort of notification could be implemented using atmosphere (aka Push).

But another funny approach is to use a XMPP server embedded in your java web application. Ok, ok, you don't have to embed it, you can just run an instance of a industrial-strenght XMPP server such as Openfire and Tigase. But hey, we're just playing a little, so I'll show you how to do it using Vysper, a little proof-of-concept developed using Apache Mina, that is simple enough for a few minutes play.

Before showing how to do it, it's nice to remember that threads and JEE applications usually don't mix, so we can play, but we must be aware of what are we doing.

First, you're going to need these JARs, most of them come from Vysper. Just a few huh?
  • aopalliance-1.0.jar
  • commons-codec-1.4.jar
  • commons-collections-3.1.jar
  • commons-io-1.4.jar
  • commons-lang-2.5.jar
  • commons-logging-1.1.jar
  • concurrent-1.3.4.jar
  • derby-10.2.1.6.jar
  • dnsjava-2.0.8.jar
  • ehcache-core-2.2.0.jar
  • fontbox-0.1.0.jar
  • jackrabbit-api-1.5.0.jar
  • jackrabbit-core-1.5.3.jar
  • jackrabbit-jcr-commons-1.5.3.jar
  • jackrabbit-spi-1.5.0.jar
  • jackrabbit-spi-commons-1.5.0.jar
  • jackrabbit-text-extractors-1.5.0.jar
  • jcl-over-slf4j-1.5.3.jar
  • jcr-1.0.jar
  • jempbox-0.2.0.jar
  • jetty-continuation-7.2.1.v20101111.jar
  • jetty-http-7.2.1.v20101111.jar
  • jetty-io-7.2.1.v20101111.jar
  • jetty-security-7.2.1.v20101111.jar
  • jetty-server-7.2.1.v20101111.jar
  • jetty-servlet-7.2.1.v20101111.jar
  • jetty-util-7.2.1.v20101111.jar
  • jetty-websocket-7.2.1.v20101111.jar
  • log4j-1.2.14.jar
  • lucene-core-2.3.2.jar
  • mina-core-2.0.2.jar
  • nbxml-0.7.jar
  • nekohtml-1.9.7.jar
  • pdfbox-0.7.3.jar
  • poi-3.0.2-FINAL.jar
  • poi-scratchpad-3.0.2-FINAL.jar
  • primefaces-4.0.jar
  • servlet-api-2.5.jar
  • slf4j-api-1.5.3.jar
  • slf4j-log4j12-1.5.3.jar
  • smack-3.1.0.jar
  • smackx-3.1.0.jar
  • spec-compliance-0.7.jar
  • spring-aop-3.0.5.RELEASE.jar
  • spring-asm-3.0.5.RELEASE.jar
  • spring-beans-3.0.5.RELEASE.jar
  • spring-context-3.0.5.RELEASE.jar
  • spring-core-3.0.5.RELEASE.jar
  • spring-expression-3.0.5.RELEASE.jar
  • vysper-core-0.7.jar
  • vysper-websockets-0.7.jar
  • xep0045-muc-0.7.jar
  • xep0060-pubsub-0.7.jar
  • xep0124-xep0206-bosh-0.7.jar
  • xercesImpl-2.8.1.jar
  • xml-apis-1.3.03.jar
Now, copy from Vysper the bogus certificate, so your XMPP server can "work" under a "secure" channel. It's called bogus_mina_tls.cert.

My xhtml looks like this

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:p="http://primefaces.org/ui">
<h:head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Messaging Prototype</title>
    <link rel="icon" type="image/png" href="favicon.ico"></link>   
</h:head>
<h:body>   
    <h:outputStylesheet library="css" name="style.css"  />

    <p:ajaxStatus style="width:16px;height:16px;" id="ajaxStatusPanel"> 
        <f:facet name="start"> 
            <h:graphicImage value="./ajaxloading.gif" /> 
        </f:facet> 
         
        <f:facet name="complete"> 
            <h:outputText value="" /> 
        </f:facet> 
    </p:ajaxStatus> 

    <h:form>   
        <p:messages id="messages" showDetail="true" autoUpdate="true" closable="true" />
        <p:spacer height="10" />
        <p:panel>
            <h:panelGrid columns="2">
                <p:commandButton value="Enter" action="#{messagingMB.sendMessage}" />
            </h:panelGrid>
        </p:panel>
        <p:spacer height="10" />
    </h:form>
</h:body>
</html>


Pretty simple huh? The Managed Bean is also easy.



import java.io.Serializable;

import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;

import org.jivesoftware.smack.XMPPException;

@ManagedBean
@ViewScoped
public class MessagingMB implements Serializable {

    private static final long    serialVersionUID    = -9092497421080796430L;
   
    @EJB
    private JSFUtilEJB jsfUtilEJB;
   
    @PostConstruct
    public void init() {
    }

    public void sendMessage() {
        try {
            new BasicClient().test();
        } catch (XMPPException e) {
            jsfUtilEJB.addErrorMessage(e,"Could not send");
        }
    }
}


and of course, the EJBs



import javax.ejb.Stateless;
import javax.faces.application.FacesMessage;
import javax.faces.application.FacesMessage.Severity;
import javax.faces.context.FacesContext;

@Stateless
public class JSFUtilEJB {

    @SuppressWarnings("unchecked")
    public <T> T findBean(String beanName) {
        FacesContext context = FacesContext.getCurrentInstance();
        return (T) context.getApplication().evaluateExpressionGet(context, "#{" + beanName + "}", Object.class);
    }

    public long addErrorMessage(String msg) {
        return addMessage(null,FacesMessage.SEVERITY_ERROR,msg);
    }
    public long addErrorMessage(Exception e,String summary){
        return addMessage(e,FacesMessage.SEVERITY_ERROR,summary);
    }
    public long addFatalErrorMessage(Exception e,String summary){
        return addMessage(e,FacesMessage.SEVERITY_FATAL,summary);
    }
    public long addInfoMessage(String summary){
        return addMessage(null,FacesMessage.SEVERITY_INFO,summary);
    }
    public long addWarnMessage(Exception e,String summary){
        return addMessage(e,FacesMessage.SEVERITY_WARN,summary);
    }

    public long addErrorMessage(Exception e) {
        return addMessage(e,FacesMessage.SEVERITY_ERROR,e.getMessage(),e.getClass().getSimpleName());
    }

    private long addMessage(Exception e,Severity severity, String summary) {
        FacesContext context = FacesContext.getCurrentInstance();
        String clientId = null;
       
        long id = -1;
       
        if (e != null){
            id = printStackTrace(e);
            FacesMessage facesMessage = null;
            if (e.getCause() instanceof org.apache.openjpa.persistence.EntityExistsException){
                facesMessage = new FacesMessage(severity,"[Error: #"+id+"] "+summary,"You are trying are to add a new object that already exists or your're trying to violate a unique constraint)" );   
            }else{
                facesMessage = new FacesMessage(severity,"[Error: #"+id+"] "+summary,e.getMessage() );
            }
            context.addMessage(clientId , facesMessage );
        }else{
            FacesMessage facesMessage = new FacesMessage(severity,summary," ");
            context.addMessage(clientId , facesMessage );
        }

        return id;
    }

    private long addMessage(Exception e,Severity severity, String summary, String detail) {
        FacesContext context = FacesContext.getCurrentInstance();
        String clientId = null;
       
        long id = -1;
        if (e != null){
            id = printStackTrace(e);       
            FacesMessage facesMessage = new FacesMessage(severity,"["+id+"] "+summary,detail );
            context.addMessage(clientId , facesMessage );
        }else{
            FacesMessage facesMessage = new FacesMessage(severity,summary,detail );
            context.addMessage(clientId , facesMessage );
        }
       
        return id;
    }

    public long printStackTrace(Exception e){
        long uniqueId = System.currentTimeMillis();
        return uniqueId;
    }

}


and



import java.io.File;
import java.io.Serializable;

import javax.annotation.PostConstruct;
import javax.ejb.Singleton;
import javax.ejb.Startup;

import org.apache.vysper.mina.TCPEndpoint;
import org.apache.vysper.storage.StorageProviderRegistry;
import org.apache.vysper.storage.inmemory.MemoryStorageProviderRegistry;
import org.apache.vysper.xmpp.addressing.EntityImpl;
import org.apache.vysper.xmpp.authorization.AccountManagement;
import org.apache.vysper.xmpp.server.XMPPServer;

@Startup
@Singleton
public class XmppEJB implements Serializable {
   
    /**
     * <br>06/09/2014
     */
    private static final long serialVersionUID = 1L;
    private boolean started;

    @PostConstruct
    public void init() {
        try {
            // choose the storage you want to use
    //        StorageProviderRegistry providerRegistry = new JcrStorageProviderRegistry();
            StorageProviderRegistry providerRegistry = new MemoryStorageProviderRegistry();
   
            final AccountManagement accountManagement = (AccountManagement) providerRegistry.retrieve(AccountManagement.class);
   
            if(!accountManagement.verifyAccountExists(EntityImpl.parse("user1@vysper.org"))) {
                accountManagement.addUser(EntityImpl.parse("user1@vysper.org"), "password");
            }
            if(!accountManagement.verifyAccountExists(EntityImpl.parse("user2@vysper.org"))) {
                accountManagement.addUser(EntityImpl.parse("user2@vysper.org"), "password");
            }
           
            XMPPServer server = new XMPPServer("vysper.org");
            server.addEndpoint(new TCPEndpoint());
            server.setStorageProviderRegistry(providerRegistry);
            server.setTLSCertificateInfo(new File("/path/to/bogus_mina_tls.cert"), "boguspw");
           
            server.start();
            System.out.println("server is running...");
        } catch (Exception e) {
            e.printStackTrace();
        }
       
        started = true;
    }

    public boolean isStarted() {
        return this.started;
    }
   
   
   
}


and the basic client, which comes from Vysper.

import java.util.Date;

import org.jivesoftware.smack.Chat;
import org.jivesoftware.smack.ConnectionConfiguration;
import org.jivesoftware.smack.MessageListener;
import org.jivesoftware.smack.PacketListener;
import org.jivesoftware.smack.Roster;
import org.jivesoftware.smack.SASLAuthentication;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.filter.PacketFilter;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Message;
import org.jivesoftware.smack.packet.Packet;
import org.jivesoftware.smack.packet.PacketExtension;
import org.jivesoftware.smack.packet.Presence;
import org.jivesoftware.smackx.packet.Time;
import org.jivesoftware.smackx.packet.Version;

public class BasicClient {

    static class IQListener implements PacketListener {

        public void processPacket(Packet packet) {
            IQ iq = (IQ) packet;
            String iqString = iq.toString();
            System.out.println("T" + System.currentTimeMillis() + " IQ: "
                    + iqString + ": " + iq.toXML());
        }
    }

    static class PresenceListener implements PacketListener {

        public void processPacket(Packet packet) {
            Presence presence = (Presence) packet;
            String iqString = presence.toString();
            final PacketExtension extension = presence
                    .getExtension("http://jabber.org/protocol/caps");
            if (extension != null)
                System.out.println("T" + System.currentTimeMillis() + " Pres: "
                        + iqString + ": " + presence.toXML());
        }
    }

    public void test() throws XMPPException {

        String me = "user2@vysper.org";
        String to = "user1@vysper.org";

        try {
            ConnectionConfiguration connectionConfiguration = new ConnectionConfiguration(
                    "localhost");
            connectionConfiguration.setCompressionEnabled(false);
            connectionConfiguration.setSelfSignedCertificateEnabled(true);
            connectionConfiguration.setExpiredCertificatesCheckEnabled(false);
//            connectionConfiguration.setDebuggerEnabled(true);
            connectionConfiguration
                    .setSecurityMode(ConnectionConfiguration.SecurityMode.required);
//            XMPPConnection.DEBUG_ENABLED = true;
            XMPPConnection connection = new XMPPConnection(
                    connectionConfiguration);
            connection.connect();

            SASLAuthentication saslAuthentication = connection
                    .getSASLAuthentication();
            saslAuthentication.authenticate(me, "password", "test");
            connection.login(me, "pqssword");

            connection.getRoster().setSubscriptionMode(
                    Roster.SubscriptionMode.accept_all);

            connection.addPacketListener(new IQListener(), new PacketFilter() {
                public boolean accept(Packet packet) {
                    return packet instanceof IQ;
                }
            });

            connection.addPacketListener(new PresenceListener(),
                    new PacketFilter() {
                        public boolean accept(Packet packet) {
                            return packet instanceof Presence;
                        }
                    });

            Chat chat = null;
            if (to != null) {
                Presence presence = new Presence(Presence.Type.subscribe);
                presence.setFrom(connection.getUser());
                String toEntity = to;
                presence.setTo(toEntity);
                connection.sendPacket(presence);

                chat = connection.getChatManager().createChat(toEntity,
                        new MessageListener() {
                            public void processMessage(Chat inchat,
                                    Message message) {
                                System.out.println("log received message: "
                                        + message.getBody());
                            }
                        });
            }

            connection.sendPacket(new Presence(Presence.Type.available,
                    "pommes", 1, Presence.Mode.available));

            Thread.sleep(1000);

            // query server version
            sendIQGetWithTimestamp(connection, new Version());

            // query server time
            sendIQGetWithTimestamp(connection, new Time());

            chat.sendMessage("Hello " + to + " at " + new Date());

            connection.disconnect();
        } catch (Throwable e) {
            e.printStackTrace(); // To change body of catch statement use File |
                                    // Settings | File Templates.
        }
        System.out.println("bye");
    }

    private static void sendIQGetWithTimestamp(XMPPConnection connection, IQ iq) {
        iq.setType(IQ.Type.GET);
        connection.sendPacket(iq);
        System.out.println("T" + System.currentTimeMillis()
                + " IQ request sent");
    }
}


We're almost set. Of course, now we need a XMPP client, such as Pidgin

First, let me just say thanks to this blog, because I don't know why, Vysper site has little to no information about how to configure Pidgin, so this blog post was really useful.

Let me show you how my pidgin user looks like








I know, it's in Portuguese.


And that's it. We're all set. Start your JSF web application and play.

Notice that the communication is bidirectional, so you can just use your XMPP client to send commands to the server. To do that, you just have to change this listener

                chat = connection.getChatManager().createChat(toEntity,
                        new MessageListener() {
                            public void processMessage(Chat inchat,
                                    Message message) {
                                System.out.println("log received message: "
                                        + message.getBody());
                            }
                        });


I wonder if we could just create a DSL to process some commands and if we could find some autocomplete pidgin plugin to write commands using this DSL. Suggestions are welcome. ;-)

ps. The EJB does not shutdown the server gracefully. But I bet there's some EJB annotation to do that in an event of a server shutdown.