Simple Stateless with callback methods
This example shows how to create a stateless session bean that uses the @PostConstruct, @PreDestroy and @AroundInvoke annotations.
CalculatorBean
package org.superbiz.stateless.basic;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.ejb.Stateless;
import javax.interceptor.AroundInvoke;
import javax.interceptor.InvocationContext;
@Stateless
public class CalculatorBean {
@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 add(int a, int b) {
return a + b;
}
public int subtract(int a, int b) {
return a - b;
}
public int multiply(int a, int b) {
return a * b;
}
public int divide(int a, int b) {
return a / b;
}
public int remainder(int a, int b) {
return a % b;
}
}
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);
}
CalculatorTest
package org.superbiz.stateless.basic;
import org.junit.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.ArrayList;
import java.util.List;
import java.util.Properties;
public class CalculatorTest implements ExecutionObserver {
private static final String JNDI = "java:global/simple-stateless-callbacks/CalculatorBean";
private 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 {
ExecutionChannel.getInstance().addObserver(this);
final EJBContainer container = EJBContainer.createEJBContainer();
{
final CalculatorBean calculator = (CalculatorBean) getContext().lookup(JNDI);
Assert.assertEquals(10, calculator.add(4, 6));
//the bean is constructed only when it is used for the first time
Assert.assertEquals("postConstruct", this.received.remove(0));
Assert.assertEquals("add", this.received.remove(0));
Assert.assertEquals(-2, calculator.subtract(4, 6));
Assert.assertEquals("subtract", this.received.remove(0));
Assert.assertEquals(24, calculator.multiply(4, 6));
Assert.assertEquals("multiply", this.received.remove(0));
Assert.assertEquals(2, calculator.divide(12, 6));
Assert.assertEquals("divide", this.received.remove(0));
Assert.assertEquals(4, calculator.remainder(46, 6));
Assert.assertEquals("remainder", this.received.remove(0));
}
{
final CalculatorBean calculator = (CalculatorBean) getContext().lookup(JNDI);
Assert.assertEquals(10, calculator.add(4, 6));
Assert.assertEquals("add", this.received.remove(0));
}
container.close();
Assert.assertEquals("preDestroy", this.received.remove(0));
Assert.assertTrue(this.received.isEmpty());
}
@Override
public void onExecution(Object value) {
System.out.println("Test step -> " + value);
this.received.add(value);
}
}
Running
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T E S T S
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Running org.superbiz.stateless.basic.CalculatorTest
INFO - ********************************************************************************
INFO - OpenEJB http://tomee.apache.org/
INFO - Startup: Sat Jul 21 09:23:38 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-stateless-callbacks
INFO - openejb.base = /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateless-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 - Creating TransactionManager(id=Default Transaction Manager)
INFO - Creating SecurityService(id=Default Security Service)
INFO - Beginning load: /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateless-callbacks/target/classes
INFO - Configuring enterprise application: /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateless-callbacks
INFO - Auto-deploying ejb CalculatorBean: EjbDeployment(deployment-id=CalculatorBean)
INFO - Configuring Service(id=Default Stateless Container, type=Container, provider-id=Default Stateless Container)
INFO - Auto-creating a container for bean CalculatorBean: Container(type=STATELESS, id=Default Stateless Container)
INFO - Creating Container(id=Default Stateless Container)
INFO - Configuring Service(id=Default Managed Container, type=Container, provider-id=Default Managed Container)
INFO - Auto-creating a container for bean org.superbiz.stateless.basic.CalculatorTest: 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-stateless-callbacks" loaded.
INFO - Assembling app: /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateless-callbacks
INFO - Jndi(name="java:global/simple-stateless-callbacks/CalculatorBean!org.superbiz.stateless.basic.CalculatorBean")
INFO - Jndi(name="java:global/simple-stateless-callbacks/CalculatorBean")
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 111 ms.
INFO - Created Ejb(deployment-id=CalculatorBean, ejb-name=CalculatorBean, container=Default Stateless Container)
INFO - Started Ejb(deployment-id=CalculatorBean, ejb-name=CalculatorBean, container=Default Stateless Container)
INFO - Deployed Application(path=/home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateless-callbacks)
Test step -> postConstruct
Test step -> add
Test step -> subtract
Test step -> multiply
Test step -> divide
Test step -> remainder
Test step -> add
INFO - Undeploying app: /home/boto/dev/ws/openejb_trunk/openejb/examples/simple-stateless-callbacks
Test step -> preDestroy
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 2.884 sec
Results :
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0