Question

I’m working on EJB client + server, and I wonder, how to deal with server data errors on client. Should I check return value on client or catch an Exception? Example, that use return value logic:

//server bean method
public int create(MyObj obj) {
    int PKID = someDataService.create(obj);
    return PKID;
}

//client
if(!(MyBean.create(obj) > 0)) {
    showMessage("Can't create MyObj");
}

Example with exceptions:

//server bean method
public void create(MyObj obj) {
    int PKID = someDataService.create(obj);
    if(!(id > 0)) {
        //only EJBExceptions will be delivered to client
        throw new EJBException(new MyDataException());
    }
}

//client
try {
    MyBean.create(obj);
}
catch(EJBException e) {
    if(e.getCause().getClass.equals(MyDataException.class)) {
        showMessage("Can't create MyObj");
    }
    else {
        showMessage("Some boring error occurred");
    }
}

I know, that return value checking instead of exceptions looks like coding in C, but all this EJB thing confuses me. Which is the better way?

Answer 1

Throw exception from your method

public void create(MyObj obj) throws MyDataException  

and annotate your custom exception with ApplicationException

@javax.ejb.ApplicationException
public class MyDataException extends Exception
{