Checked application exception

[Alexandre Fradin]

Hi,

Application exceptions that are checked exceptions
may be defined as such by being listed in the throws clauses of the methods of the bean�s business
interface.

Does it mean that an Exception may be a Application exception for a business method and a system exception for an other one, for example :

    
public class MyException extends Exception{}
 
@Stateless
public class MyBean implements MyLocal{
 
public void m1() throws MyException{
  throw new MyException(); // here an application exception
}
public void m2() throws Exception{
  throw new MyException(); // there a system exception
}
}

Is my example true?

Thanks for help.

[ August 11, 2008: Message edited by: Alexandre Fradin ]
[ August 11, 2008: Message edited by: Alexandre Fradin ]

[Christophe Verré]

// here an application exception
// there a system exception

Your example is not that great, as you're throwing the same exception System exceptions are not application exceptions. There are three patterns :

Application exceptions that are checked exceptions may be defined as such by being listed in the throws clauses of the methods.

An application exception that is an unchecked exception is defined as an application exception by annotating it with the ApplicationException metadata annotation, or denoting it in the deployment descriptor with the application-exception element.

A system exception is an exception that is a java.rmi.RemoteException (or one of its subclasses) or a RuntimeException that is not an application exception.

Your example uses a checked exception (extending Exception), so it has to be defined in the throws clause of the method. Here is another example, with two application exceptions, one checked and one unchecked :

public class MyCheckedException extends Exception{}
 
@ApplicationException
public class MyUncheckedException extends RuntimeException {
}
 
@Stateless
public class MyBean implements MyLocal{
 
public void m1() throws MyCheckedException {
  throw new MyCheckedException();  // here is a checked application exception
}
public void m2() {
  throw new MyUncheckedException(); // there is an unchecked application exception
}
}

[Alexandre Fradin]

Ok thank you Christophe.

I missed the third point... So in my example, MyException is an application exception for both m1() and m2().

[Christophe Verré]

Yes, a checked application exception.