3 Replies Latest reply on May 20, 2011 8:21 PM by Swaminathan Bhaskar

    JBoss Cache 3.x Eviction notification

    Swaminathan Bhaskar Newbie

      I looked at the CacheListener and did not find any way for me to get notified when an object stored under a FQN is evicted due to expiry etc. Is there any other way I could register a callback to be notified when a key is evicted ? Any help appreciated

        • 1. JBoss Cache 3.x Eviction notification
          Swaminathan Bhaskar Newbie

          Any pointers on how to achieve this would be of great help. Can someone please help ?

          • 2. JBoss Cache 3.x Eviction notification
            jaysmith Newbie

            Hi,

             

            you sure the CacheListener didn't work? I have this code for a listener and it works pretty well if memory serves me correctly.

             

            import java.text.SimpleDateFormat;
            import java.util.Date;

             

            import org.jboss.cache.notifications.annotation.CacheListener;
            import org.jboss.cache.notifications.annotation.CacheStarted;
            import org.jboss.cache.notifications.annotation.NodeActivated;
            import org.jboss.cache.notifications.annotation.NodeCreated;
            import org.jboss.cache.notifications.annotation.NodeEvicted;
            import org.jboss.cache.notifications.annotation.NodeLoaded;
            import org.jboss.cache.notifications.annotation.NodePassivated;
            import org.jboss.cache.notifications.annotation.NodeRemoved;
            import org.jboss.cache.notifications.annotation.NodeVisited;
            import org.jboss.cache.notifications.event.CacheStartedEvent;
            import org.jboss.cache.notifications.event.NodeActivatedEvent;
            import org.jboss.cache.notifications.event.NodeCreatedEvent;
            import org.jboss.cache.notifications.event.NodeEvictedEvent;
            import org.jboss.cache.notifications.event.NodeLoadedEvent;
            import org.jboss.cache.notifications.event.NodePassivatedEvent;
            import org.jboss.cache.notifications.event.NodeRemovedEvent;
            import org.jboss.cache.notifications.event.NodeVisitedEvent;

             

            @CacheListener
            public class CustomCacheListener {
                @CacheStarted
                public final void cacheStarted(final CacheStartedEvent e) {
                    System.out.println(format(new Date()) + " [CustomCacheListener] Cache started");
                }

             

                private String format(Date date) {
                    SimpleDateFormat formatter = new SimpleDateFormat("HH:MM:ss.SSS");
                    return formatter.format(date);
                }

             

                @NodeActivated
                public final void nodeActivated(final NodeActivatedEvent ne) {
                    System.out.println(format(new Date()) + " [CustomCacheListener] Activated key: " + ne.getFqn().toString());
                }

             

                @NodeCreated
                public final void nodeCreated(final NodeCreatedEvent ne) {
                    System.out.println(format(new Date()) + " [CustomCacheListener] Created key: " + ne.getFqn().toString());
                }

             

                @NodeEvicted
                public final void nodeEvicted(final NodeEvictedEvent ne) {
                    System.out.println(format(new Date()) + " [CustomCacheListener] Evicted key: " + ne.getFqn().toString());
                }

             

                @NodeLoaded
                public final void nodeLoaded(final NodeLoadedEvent ne) {
                    System.out.println(format(new Date()) + " [CustomCacheListener] Loaded key: " + ne.getFqn().toString());
                }

             

                @NodePassivated
                public final void nodePassivated(final NodePassivatedEvent ne) {
                    System.out.println(format(new Date()) + " [CustomCacheListener] Passivated key: " + ne.getFqn().toString());
                }

             

                @NodeRemoved
                public final void nodeRemoved(final NodeRemovedEvent cere) {
                    System.out.println(format(new Date()) + " [CustomCacheListener] Removed key: " + cere.getFqn().toString());
                }

             

                @NodeVisited
                public final void nodeVisited(final NodeVisitedEvent ne) {
                    System.out.println(format(new Date()) + " [CustomCacheListener] Visited key: " + ne.getFqn().toString());
                }
            }

            • 3. Re: JBoss Cache 3.x Eviction notification
              Swaminathan Bhaskar Newbie

              Hi Jay,

               

              First off - thank you very much for your response. Much appreciated. Yes, I did try that and it does not work as I would expect. Let me provide you the code:

               

              Here is the listener code:

               

              import org.jboss.cache.notifications.annotation.*;

              import org.jboss.cache.notifications.event.*;

               

              @CacheListener

              public class MyCacheListener {

                  @NodeEvicted

                   public void logNodeEvent(NodeEvictedEvent ne) {

                       System.out.println("***** Evicted FQN: " + ne.getFqn() + ", Type: " + ne.getType());

                   }

              }

               

              Here is the main code:

               

              import org.jboss.cache.*;

               

              public class MyJBossCacheTest1 {

                  @SuppressWarnings({ "rawtypes", "unchecked" })

                  public static void main(String[] args) {

                      if (args.length != 1) {

                          System.out.printf("Usage: java %s <config-file>\n", MyJBossCacheTest1.class.getName());

                          System.exit(1);

                      }

               

                      CacheFactory factory = new DefaultCacheFactory();

               

                      Cache cache = factory.createCache(args[0]);

                      cache.addCacheListener(new MyCacheListener());

                      cache.start();

               

                      Fqn myUserData = Fqn.fromString("/my/data/user");

               

                      // Prime Cache with User Data

                      {

                          int MAX_USERS = 3;

                          for (int i = 1; i <= MAX_USERS; i++) {

                              String user = "u." + i;

                              String email = "user_" + i +"@nowhere.com";

               

                              cache.put(myUserData, user, email);

                          }

                      }

               

                      // Access User - "u.2"

                      {

                          String user = (String) cache.get(myUserData, "u.2");

               

                          if (user != null) {

                              System.out.println("Accessed - " + user);

                          }

                          else {

                              System.out.println("Access of u.2 is null");

                          }

                      }

               

                      // Access Users after sleep of 30 secs

                      {

                          System.out.println("Ready to sleep for 30 secs ...");

               

                          try {

                              Thread.sleep(30000);

                          }

                          catch (Exception ex) {

                          }

               

                          System.out.println("Ready to access user(s) ...");

               

                          int MAX_USERS = 3;

                          for (int i = 1; i <= MAX_USERS; i++) {

                              String user = (String) cache.get(myUserData, "u."+i);

                              if (user != null) {

                                  System.out.println("Accessed - " + user);

                              }

                              else {

                                  System.out.println("Access of u." + i + " is null");

                              }

                          }

                      }

               

                      cache.stop();

                      cache.destroy();

                  }

              }

               

              Was expection to see the FQNs: /my/user/data/u.1, /my/data/user/u.2, and /my/data/user/u.3 to be shown by the listener on eviction. But instead I see the following:

               

              ***** Evicted FQN: /my/data/user, Type: NODE_EVICTED

              ***** Evicted FQN: /my/data/user, Type: NODE_EVICTED

               

              In other words I would not know which keys were evicted ... Any ideas ?