index-group=Unrevised type=page status=published title=Simple Stateful with callback methods

This example shows how to create a stateful session bean that uses the @PrePassivate, @PostActivate, @PostConstruct, @PreDestroy and @AroundInvoke annotations.

## CallbackCounter

    package org.superbiz.counter;

    import javax.annotation.PostConstruct;
    import javax.annotation.PreDestroy;
    import javax.ejb.PostActivate;
    import javax.ejb.PrePassivate;
    import javax.ejb.Stateful;
    import javax.ejb.StatefulTimeout;
    import javax.interceptor.AroundInvoke;
    import javax.interceptor.InvocationContext;
    import java.io.Serializable;
    import java.util.concurrent.TimeUnit;

    @Stateful
    @StatefulTimeout(value = 1, unit = TimeUnit.SECONDS)
    public class CallbackCounter implements Serializable {

        private int count = 0;

        @PrePassivate
        public void prePassivate() {
            ExecutionChannel.getInstance().notifyObservers("prePassivate");
        }

        @PostActivate
        public void postActivate() {
            ExecutionChannel.getInstance().notifyObservers("postActivate");
        }

        @PostConstruct
        public void postConstruct() {
            ExecutionChannel.getInstance().notifyObservers("postConstruct");
        }

        @PreDestroy
        public void preDestroy() {
            ExecutionChannel.getInstance().notifyObservers("preDestroy");
        }

        @AroundInvoke
        public Object intercept(InvocationContext ctx) throws Exception {
            ExecutionChannel.getInstance().notifyObservers(ctx.getMethod().getName());
            return ctx.proceed();
        }

        public int count() {
            return count;
        }

        public int increment() {
            return ++count;
        }

        public int reset() {
            return (count = 0);
        }
    }

## ExecutionChannel

    package org.superbiz.counter;

    import java.util.ArrayList;
    import java.util.List;

    public class ExecutionChannel {
        private static final ExecutionChannel INSTANCE = new ExecutionChannel();

        private final List<ExecutionObserver> observers = new ArrayList<ExecutionObserver>();

        public static ExecutionChannel getInstance() {
            return INSTANCE;
        }

        public void addObserver(ExecutionObserver observer) {
            this.observers.add(observer);
        }

        public void notifyObservers(Object value) {
            for (ExecutionObserver observer : this.observers) {
                observer.onExecution(value);
            }
        }
    }

## ExecutionObserver

    package org.superbiz.counter;

    public interface ExecutionObserver {

        void onExecution(Object value);

    }

## CounterCallbacksTest

    package org.superbiz.counter;

    import junit.framework.Assert;
    import org.junit.Test;

    import javax.ejb.embeddable.EJBContainer;
    import javax.naming.Context;
    import javax.naming.InitialContext;
    import javax.naming.NamingException;
    import java.util.*;

    public class CounterCallbacksTest implements ExecutionObserver {
        private static List<Object> received = new ArrayList<Object>();

        public Context getContext() throws NamingException {
            final Properties p = new Properties();
            p.put(Context.INITIAL_CONTEXT_FACTORY, "org.apache.openejb.core.LocalInitialContextFactory");
            return new InitialContext(p);

        }

        @Test
        public void test() throws Exception {
            final Map<String, Object> p = new HashMap<String, Object>();
            p.put("MySTATEFUL", "new://Container?type=STATEFUL");
            p.put("MySTATEFUL.Capacity", "2"); //How many instances of Stateful beans can our server hold in memory?
            p.put("MySTATEFUL.Frequency", "1"); //Interval in seconds between checks
            p.put("MySTATEFUL.BulkPassivate", "0"); //No bulkPassivate - just passivate entities whenever it is needed
            final EJBContainer container = EJBContainer.createEJBContainer(p);

            //this is going to track the execution
            ExecutionChannel.getInstance().addObserver(this);

            {
                final Context context = getContext();

                CallbackCounter counterA = (CallbackCounter) context.lookup("java:global/simple-stateful-callbacks/CallbackCounter");
                Assert.assertNotNull(counterA);
                Assert.assertEquals("postConstruct", received.remove(0));

                Assert.assertEquals(0, counterA.count());
                Assert.assertEquals("count", received.remove(0));

                Assert.assertEquals(1, counterA.increment());
                Assert.assertEquals("increment", received.remove(0));

                Assert.assertEquals(0, counterA.reset());
                Assert.assertEquals("reset", received.remove(0));

                Assert.assertEquals(1, counterA.increment());
                Assert.assertEquals("increment", received.remove(0));

                System.out.println("Waiting 2 seconds...");
                Thread.sleep(2000);

                Assert.assertEquals("preDestroy", received.remove(0));

                try {
                    counterA.increment();
                    Assert.fail("The ejb is not supposed to be there.");
                } catch (javax.ejb.NoSuchEJBException e) {
                    //excepted
                }

                context.close();
            }

            {
                final Context context = getContext();

                CallbackCounter counterA = (CallbackCounter) context.lookup("java:global/simple-stateful-callbacks/CallbackCounter");
                Assert.assertEquals("postConstruct", received.remove(0));

                Assert.assertEquals(1, counterA.increment());
                Assert.assertEquals("increment", received.remove(0));

                ((CallbackCounter) context.lookup("java:global/simple-stateful-callbacks/CallbackCounter")).count();
                Assert.assertEquals("postConstruct", received.remove(0));
                Assert.assertEquals("count", received.remove(0));

                ((CallbackCounter) context.lookup("java:global/simple-stateful-callbacks/CallbackCounter")).count();
                Assert.assertEquals("postConstruct", received.remove(0));
                Assert.assertEquals("count", received.remove(0));

                System.out.println("Waiting 2 seconds...");
                Thread.sleep(2000);
                Assert.assertEquals("prePassivate", received.remove(0));

                context.close();
            }
            container.close();

            Assert.assertEquals("preDestroy", received.remove(0));
            Assert.assertEquals("preDestroy", received.remove(0));

            Assert.assertTrue(received.toString(), received.isEmpty());
        }

        @Override
        public void onExecution(Object value) {
            System.out.println("Test step -> " + value);
            received.add(value);
        }
    }

# Running

    -------------------------------------------------------
     T E S T S
    -------------------------------------------------------
    Running org.superbiz.counter.CounterCallbacksTest
    INFO - ********************************************************************************
    INFO - OpenEJB http://tomee.apache.org/
    INFO - Startup: Sat Jul 21 08:18:28 EDT 2012
    INFO - Copyright 1999-2012 (C) Apache OpenEJB Project, All Rights Reserved.
    INFO - Version: 4.1.0
    INFO - Build date: 20120721
    INFO - Build time: 04:06
    INFO - ********************************************************************************
    INFO - openejb.home = /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateful-callbacks
    INFO - openejb.base = /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateful-callbacks
    INFO - Created new singletonService org.apache.openejb.cdi.ThreadSingletonServiceImpl@527736bd
    INFO - Succeeded in installing singleton service
    INFO - Using 'javax.ejb.embeddable.EJBContainer=true'
    INFO - Cannot find the configuration file [conf/openejb.xml].  Will attempt to create one for the beans deployed.
    INFO - Configuring Service(id=Default Security Service, type=SecurityService, provider-id=Default Security Service)
    INFO - Configuring Service(id=Default Transaction Manager, type=TransactionManager, provider-id=Default Transaction Manager)
    INFO - Configuring Service(id=MySTATEFUL, type=Container, provider-id=Default Stateful Container)
    INFO - Creating TransactionManager(id=Default Transaction Manager)
    INFO - Creating SecurityService(id=Default Security Service)
    INFO - Creating Container(id=MySTATEFUL)
    INFO - Using directory /tmp for stateful session passivation
    INFO - Beginning load: /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateful-callbacks/target/classes
    INFO - Configuring enterprise application: /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateful-callbacks
    INFO - Auto-deploying ejb CallbackCounter: EjbDeployment(deployment-id=CallbackCounter)
    INFO - Configuring Service(id=Default Managed Container, type=Container, provider-id=Default Managed Container)
    INFO - Auto-creating a container for bean org.superbiz.counter.CounterCallbacksTest: Container(type=MANAGED, id=Default Managed Container)
    INFO - Creating Container(id=Default Managed Container)
    INFO - Using directory /tmp for stateful session passivation
    INFO - Enterprise application "/home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateful-callbacks" loaded.
    INFO - Assembling app: /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateful-callbacks
    INFO - Jndi(name="java:global/simple-stateful-callbacks/CallbackCounter!org.superbiz.counter.CallbackCounter")
    INFO - Jndi(name="java:global/simple-stateful-callbacks/CallbackCounter")
    INFO - Existing thread singleton service in SystemInstance() org.apache.openejb.cdi.ThreadSingletonServiceImpl@527736bd
    INFO - OpenWebBeans Container is starting...
    INFO - Adding OpenWebBeansPlugin : [CdiPlugin]
    INFO - All injection points are validated successfully.
    INFO - OpenWebBeans Container has started, it took 225 ms.
    INFO - Created Ejb(deployment-id=CallbackCounter, ejb-name=CallbackCounter, container=MySTATEFUL)
    INFO - Started Ejb(deployment-id=CallbackCounter, ejb-name=CallbackCounter, container=MySTATEFUL)
    INFO - Deployed Application(path=/home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateful-callbacks)
    Test step -> postConstruct
    Test step -> count
    Test step -> increment
    Test step -> reset
    Test step -> increment
    Waiting 2 seconds...
    Test step -> preDestroy
    INFO - Removing the timed-out stateful session bean instance 583c10bfdbd326ba:57f94a9b:138a9798adf:-8000
    INFO - Activation failed: file not found /tmp/583c10bfdbd326ba=57f94a9b=138a9798adf=-8000
    Test step -> postConstruct
    Test step -> increment
    Test step -> postConstruct
    Test step -> count
    Test step -> postConstruct
    Test step -> count
    Waiting 2 seconds...
    Test step -> prePassivate
    INFO - Passivating to file /tmp/583c10bfdbd326ba=57f94a9b=138a9798adf=-7fff
    Test step -> preDestroy
    INFO - Removing the timed-out stateful session bean instance 583c10bfdbd326ba:57f94a9b:138a9798adf:-7ffe
    Test step -> preDestroy
    INFO - Removing the timed-out stateful session bean instance 583c10bfdbd326ba:57f94a9b:138a9798adf:-7ffd
    INFO - Undeploying app: /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateful-callbacks
    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 7.487 sec

    Results :

    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

    [INFO] ------------------------------------------------------------------------
    [INFO] BUILD SUCCESS
    [INFO] ------------------------------------------------------------------------
    [INFO] Total time: 15.803s
    [INFO] Finished at: Sat Jul 21 08:18:35 EDT 2012
    [INFO] Final Memory: 11M/247M
    [INFO] ------------------------------------------------------------------------