What required to run Java Bean?

[Sri Gnana]

What required to run Java Bean?

[ramprasad madathil]

jvm , perhaps u could elaborate on what u really require ?

ram.

[Ernest Friedman-Hill]

Indeed. But let's have this conversation in "Java in General (Beginner)." I'm moving this thread over there.

[Joel McNary]

A Java Bean (not to be confused with an Enterprise Java Bean -- completely different beast) is simply a class that has a default (no-argument) constructor, can be serialized, and exposes its member variable through getters and setters.

[Joe Tseng]

I was asked this question before but I couldn't give a straight answer. I think this thread is the right place to ask... So what IS the difference between a JavaBean and EJB?

Couldn't you have some of the the same characteristics of a bean be put into an EJB? Say I want to write a stateless session EJB; couldn't I create methods to implement business logic in either type of bean? (I'm ignoring the remote and home interfaces for now and focusing on just the beans.)
[ January 28, 2005: Message edited by: Joe Tseng ]

[Steven Bell]

Any Java Object can be a 'bean'. The term carries vary little requirments and is minimally invasive. You must have a no-args constructor, and getters and setters for your 'properties'. That's it.

public class Address{
  private String street;
  private String city;
  private String state;
  private int zip;
 
  public Address(){
  }
 
  public void setStreet(String s){
    street = s;
  }
  public String getStreet(){
    return street;
  }
  public void setCity(String c){
    city = c;
  }
  public String getCity(){
    return city;
  }
  ...//other getters and setters
}

that is a 'bean'. Nice and easy.

An EJB is a monstrous beast that must be hunted down and drug through the street while we all poke it with pitchforks and ...

oh, sorry about that.

[Joe Tseng]

So from your comment, my impression is that an EJB can be a JavaBean with alot more crap piled on top of it (remote/home/local-home interfaces) that have certain aspects of its behavior and interaction controlled by the J2EE container/server, right?

[Steven Bell]

Yes. But I would like to put some quote from the book Better, Faster, Lighter Java.

It has a table with serveral 'golden hammers' and where they can be properly used. Part of the table is:

EJB entities

Suitable for > Nothing

Not suited for > Sane applications



EJB(stateless session beans, MDB)

Suitable for > Distributed, transactional facades
Secure, distributed transaction monitor

Not suitable for > Lightweight applications
Applications where transactions are limited to one database