In AWT event handling, an event handling class can implement WindowListener
(lot's of work) or extend WindowAdpater(less work). In swing, a table model
can implement TableModel (lot's of work) or extend AbtractTableModel (less
work). I have been using this same idea with ejb-classes for a few years now
(See DefaultSessionBean class shown below). However, I never see it in any
books or sample code and wonder why.

I am posting the class for two reasons:

1. Does anyone see any problem with using this class?
2. If not, feel free to use it.

Note: I am already aware of a few issues:

1. You must be careful not to pass "this"
2. You are precluded from inheriting from some other class (due to Java's
single inheritance)
3. If you misspell a SessionBean call-back method, it won't be caught by the
compiler.

These are all fairly minor.

Below is the class:

==========================================================

/* This class provides default implementations of the
SessionBean interface and no-op implementations of
EJBObject's methods. This helper class provides two benefits:

1. No need to mindlessly type-in SessionBeans's
   methods, which are almost always no-op or boiler-plate.
   IMO, inheriting these default implementations is more
   elegant than using code-generation. This class is similar
   in concept to AWT's adapter classes
   (i.e. WindowAdapter,MouseAdapter) or swing's "default"
   classes (i.e. DefaultTableModel, DefaultTreeModel).

2. The ejb-class can now implement the remote interface.
   This way, if you don't properly implement the interface,
   you receive a compile-time error rather than a deploy-time
   error (which can be cryptic at times).
   See Section 9.2.2 of the EJB 1.1 Spec.

   Note: when passing a self reference to another class,
   be sure to use:
     someOtherClass.foo(ejbContext.getEJBObject())
   rather than:
     someOtherClass.foo(this)

Dave Ford
http://www.smart-soft.com */

package ss.util;

import javax.ejb.*;
import javax.naming.*;

public class DefaultSessionBean implements EJBObject,SessionBean{

  protected SessionContext ejbContext;
  protected Context namingContext;
  protected boolean debug = true;

  /* methods from EJBObject */
  public EJBHome getEJBHome(){ return null; }
  public Handle getHandle(){return null;}
  public Object getPrimaryKey(){return null;}
  public boolean isIdentical(EJBObject obj){return false;}
  public void remove(){}


  /* methods from SessionBean */

  public void ejbActivate() {
    if(debug) System.out.println(this + " - ejbActivate");
  }

  public void ejbPassivate() {
    if(debug) System.out.println(this + " - ejbPassivate");
  }

  public void ejbRemove() {
    if(debug) System.out.println(this + " - ejbRemove");
  }

  public void setSessionContext(SessionContext c){
    if(debug) System.out.println(this + " - setSessionContext");
    ejbContext = c;
    try{
      namingContext = new InitialContext();
    }
    catch(NamingException ex){
      throw new EJBException(ex);
    }
  }
}

i can advice you a good EJB book with title "Enterprise JavaBeans" by Richard Monson-Haefel from O'REILLY

That's funny. I own that book. Does it address this topic? Either I missed it or I have old version of the book.