What is the difference between ejb2.0 and ejb3.0 and i reviewed in net that ejb 3.0 using POJO(plain old java objects) what is pojoi want the reply for this

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viswanath

  • Oct 7th, 2006
 

pls reply

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Jyoti

  • Oct 17th, 2007
 

1. As part of ejb2.0 we are using EntityBeans for to access the database.But as part of ejb3.0 we are using the JPA(Java Persistance API) for to access the database and some portability issues.But this Api is same as some orm products like hibernate, Toplink, JDO. But JPA is better than these orm products in case of portability.Because it is using the same api called JPA.

2. EJB2.0 has Deployment descriptors but in EJB3.0 has no Deployment Descriptors.

3.  EJB2.0 we have to write Home and Remote Interfaces But in EJB3.0 No need to write Home and remote interfaces.

4.  In EJB3.0 We are identifying all entities with '@' symbol.

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EJB 2.0 and EJB 3.0 both help you in the same way for what you pay for the EJB container. The central point about EJB 3.0 is that it has simplifed the life of developers.
How ?
1) Deployment Descriptors have been replaced by annotations that can be done in Java Code itself .
2) The Concept of using POJO probably inspired from the popularity of Spring Framework has been introduced simplifying the coding process.
3) Now you need not code the home and component interfaces that were pretty complex when you consider some simple business implemention. That was a real overhead in ejb 2.0 .

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kuntal

  • Jul 29th, 2011
 


Actually EJB 3.0 is a combination of POJO ( Plain Old Java Object) and POJI ( Plain Old Java Interface), POJO is a bean class, where we have to write our business logics. And the method signature should have to declare in POJI. POJI may be Local or Home interface. POJO & POJI may declare in EJB module.

If any problem discuss with me.

Thank u...

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the full form of POJO is Plane Old Java Class (generally O stands for Object), it means a simple java class which has some property (private variables) and its public setter and getter methods(setter methods sets the values in the fields and getter methods returns the field values).

note:- no any POJO class should inherit any predefined class or interfaces.

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using ejb2 framework application provides the business layer logic's in distributive and secured manner but it is little bit heavy weighted and complex, so to reduce its complexity and to overcome these problems ejb 3is introduced it is light weighted. that uses annotations so coding complexities also reduced.

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