Mission Accomplished!!!

   Today I've passed "Oracle Certified Professional Java EE Business Component Developer" exam with score 90%. I used the most standard suite of OCPJBCD materials:

• Enterprise JavaBeans™ 3.1 specification - complete data source, you can find everything here
• OCP JavaEE 6 EJB Developer Study Notes by Ivan A Krizsan - outstanding notes, focused on practical part
• Enthuware 1Z0-895 EJB V6 mock tests - very good and I think the cheapest mock exams.

   This should be enough, but you can also read some other books eg. "EJB 3 in Action" or "Enterprise JavaBeans 3.1" and remeber to visit Big Moose Saloon. 

Finally another OCPJBCD question, which I sadly screwed up:

A Singleton bean can expose which of the following client views?

1. An asynchronous message destination
2. Web Service view
3. Message Driven
4. EJB 2.x Remote home
5. EJB 3.x local business
6. JPA Entity view

Do you know? The correct answer is 2,5.

Asynchronous methods executed not via Container

   I’m preparing to OCPJBCD currently, so I will start my blogging with topic related to this exam. It is about using asynchronous methods.

package pl.mariusz.marciniak.bean;

import javax.annotation.Resource;
import javax.ejb.Asynchronous;
import javax.ejb.SessionContext;
import javax.ejb.Stateless;

@Stateless
public class AsynchMethodBeanTest {
 
 @Resource
 SessionContext beanContext;
 
 @Asynchronous
 public void asynchMethod() {
  try {
   Thread.sleep(1000);
  } catch (InterruptedException e) {
   e.printStackTrace();
  }
 }
 
 public void invokeMethod() {
  long time = System.currentTimeMillis();
  asynchMethod();
  System.out.println("Execution time :"+(System.currentTimeMillis()-time));
  
 }
}

Do you know what will be the output, if we execute invokeMethod method?
...
...
...

The answer can be "Execution time :1001". For sure it will be value not lower than 1000. It is because execution is out of the container, so it is not asynchronous in fact. How we can change it? We can replace invokeMethod with one below.

public void invokeMethod() {
  long time = System.currentTimeMillis();
  beanContext.getBusinessObject(AsynchMethodBeanTest.class).asynchMethod();
  System.out.println("Execution time :"+(System.currentTimeMillis()-time));
 }

Now it took 2 ms on my machine. Hope you like it.