Create notification producer and consumer using tooling

Create notification producer and consumer using tooling

Author:	Krishna C Shastry, Saurabh Dravid
email:	krishna.shastry@in.ibm.com	sadravid@in.ibm.com
Last updated:

Create a notification producer resource

• We will take a file system as a notification producer resource, which will notify the consumer at some specific time interval about the file space change event.
• Create a new Manageability Endpoint Project by the name of ProducerModel. All our Notification producer related artifacts will be stored in this project.
  
  
  
  
• For this resource we create a capability which publishes the file system space change events to the consumer. Create a new capability by specifying following user inputs defined in following screenshot. Click Finish.
  
  
  
  
• Tooling will open this newly created capability with Capability Editor. Move to the Topics tab in the editor and add a new Root Topic by providing the Topic namespace as "http://www.eclipse.org/FileSpaceChangeEvent/capability/Topics" and Root topic name as "FileSpaceChange".
  
  
  
  
• Create a new Manageable resource type (WSDM resource type) and add the "NotificationProducer" and "FileSpaceChangeEvent" capability to it.
  
  
  
  
  
  
• Right click the "FileSystem.mrt" file and select the option Generate Java Code. This will bring a new wizard to do the code generation for defined managed resource type. Provide the Output project name as "FileSystem".
  
  
  
  
• After doing the code generation remove the java package "org.eclipse.tptp.wsdm.runtime.capability" from "FileSystem" web project. The classes available in this package are already available in tools.jar.
  
  
• Open Java class in /FileSystem/JavaSource by the name of org.eclipse.www.FileSpaceChangeEvent.capability.MyCapability and put the following code in this class. This class will publish the file system space change notification messages at specific time interval.
  
  

  package org.eclipse.www.FileSpaceChangeEvent.capability;
  
  import javax.xml.namespace.QName;
  
  import org.apache.muse.core.AbstractCapability;
  import org.apache.muse.util.xml.XmlUtils;
  import org.apache.muse.ws.addressing.soap.SoapFault;
  import org.apache.muse.ws.notification.NotificationProducer;
  import org.apache.muse.ws.notification.WsnConstants;
  import org.w3c.dom.Element;
  
  public class MyCapability extends AbstractCapability
  {
      public QName TOPIC_QNAME = new QName("http://www.eclipse.org/FileSpaceChangeEvent/capability/Topics","FileSpaceChange","tns");
      private final int TIME_INTERVAL_SECONDS = 3;
  	
  	public void initialize() throws SoapFault 
      {
          //
          //The following call is necessary to property initialize the resource
          //
          super.initialize();
  
          //
          //TODO Perform any needed initialization for this empty capability
          //
      }
      
      public void initializeCompleted() throws SoapFault
      {
      	super.initializeCompleted();
      	
      	
      	
      	Thread thread = new Thread(){
      		
      		public void run()
      		{
      			String message = "File space changed";
  				QName messageName = new QName("http://org.eclipse/FileSystem",
  						"FileSpaceChangeMessage", "tns");
  				Element payload = XmlUtils.createElement(messageName,
  						message);
  				NotificationProducer producer = (NotificationProducer) getResource()
  						.getCapability(WsnConstants.PRODUCER_URI);
      			while (true) {
      				try {
  						Thread.sleep(TIME_INTERVAL_SECONDS * 1000);
  					} catch (InterruptedException e1) {
  						e1.printStackTrace();
  					}
  					try {
  						producer.publish(TOPIC_QNAME, payload);
  					} catch (SoapFault e) {
  						e.printStackTrace();
  					}
  				}
      		}
      	};
      	
      	thread.start();
      }
  
  }

Create a notification consumer resource

• We will prepare a consumer resource which will listen to the file system producer resource and print the received messages to console.
  
• Create a new Manageability Endpoint Project by the name of ConsumerModel. All our Notification consumer related artifacts will be stored in this project.
  
  
• For this resource we create an empty capability listens to the FileSystemProducer resource. Create a new capability by specifying following user inputs defined in following screenshot. Click Finish.
  
  
  
  
• Create a new Manageable resource type (WSDM resource type) and add the "NotificationConsumer" and "FileSpaceChangedEventConsumer" capability to it.
  
  
  
  
  
  
• Right click the "FileSystemConsumerType.mrt" file and select the option Generate Java Code. This will bring a new wizard to do the code generation for defined managed resource type. Provide the Output project name as "Consumer".
  
  
  
  
• Open Java class in /Consumer/JavaSource by the name of org.eclipse.www.FileSpaceChangedEventConsumer.capability and put the following code in this class. This class will listen to the producer and prints the received message to console.
  
  

  
  package org.eclipse.www.FileSpaceChangedEventConsumer.capability;
  
  import org.apache.muse.core.AbstractCapability;
  import org.apache.muse.ws.addressing.soap.SoapFault;
  import org.apache.muse.ws.notification.NotificationConsumer;
  import org.apache.muse.ws.notification.NotificationMessage;
  import org.apache.muse.ws.notification.NotificationMessageListener;
  import org.apache.muse.ws.notification.WsnConstants;
  
  public class MyCapability extends AbstractCapability implements NotificationMessageListener
  {
      public void initialize() throws SoapFault 
      {
          super.initialize();
      }
      
  
  	public void initializeCompleted() throws SoapFault 
  	{
  		super.initializeCompleted();
  		
  		NotificationConsumer consumer = (NotificationConsumer) getResource().getCapability(WsnConstants.CONSUMER_URI);
  		consumer.addMessageListener(this);
  	}
  
  	public boolean accepts(NotificationMessage arg0) {
  		return true;
  	}
  
  	public void process(NotificationMessage message) throws SoapFault {
  
  		System.out.println("I recieved following message" + message);
  	}
  
  }
  

Create a consumer client

• Deploy the resources FileSystem and Consumer on tomacat.
• Create package in /Consumer/JavaSource by the name of org.eclipse.test.client
• Create a class by the name ConsumerTestClient and put the following code in this class.This will create client which subscribes to the producer resource.

  package org.eclipse.test.client;
  
  import java.net.InetAddress;
  import java.net.URI;
  import java.net.UnknownHostException;
  
  import org.apache.muse.ws.addressing.EndpointReference;
  import org.apache.muse.ws.notification.remote.NotificationProducerClient;
  
  public class ConsumerTestClient
  {    
      public static void main(String[] args)
      {
          try
          {
              String PRODUCER_URI = "http://localhost:8080/FileSystem/services/FileSystem";
              String CONSUMER_URI = "http://localhost:8080/Consumer/services/FileSystemConsumerType";
          	
          	EndpointReference producerEPR = new EndpointReference(URI.create(PRODUCER_URI));
              EndpointReference consumerEPR = new EndpointReference(URI.create(CONSUMER_URI));
          	
          	//
              // null filter == send all messages to consumer
              //
              NotificationProducerClient producer = new NotificationProducerClient(producerEPR);
              producer.setTrace(true);
              producer.subscribe(consumerEPR, null, null);
          }
          
          catch (Throwable error)
          {
              error.printStackTrace();
          }
      }
  }
  

• Run the java class ConsumerTestClient.This will print the message received to the tomcat console.