Programming Tutorials

By: Michael Sikora, PACKT publishing : 2008-11-26

Description: This is an extract from the book, EJB 3 Developer Guide from the 3rd Chapter on Entities published by PACKT publishing. Entities are classes that need to be persisted; their state is stored outside the application, typically in a relational database. Unlike session beans, entities do not have business logic other than validation. As well as storing such entities, we want to query, update, and delete them.

By: Saravanan D. Rao : 2008-09-18

Description: Web services technologies provide a language-neutral, environment-neutral programming model that accelerates application integration inside and outside the enterprise.

By: Paul Allen and Joseph Bambara : 2008-08-25

Description: Here we review the component architecture of EJBs. We also cover the required classes and interfaces for EJB, which include the home and remote interfaces, the XML deployment descriptor, the business logic (bean) class, and the context objects. While these names may or may not be meaningful to you at this point, you will soon understand how each of these pieces fits into the EJB component model.

By: Paul Allen and Joseph Bambara : 2008-08-25

Description: A session bean is an EJB that is created by a client and usually exists only for the duration of a single client-server session. A session bean usually performs operations such as calculations or database access on behalf of the client. While a session bean may be transactional, it is not recoverable if a system crash occurs. Session bean objects can be stateless or they can maintain a conversational state across methods and transactions. If a session bean maintains a state, the EJB container manages this state if the object must be removed from memory. However, persistent data must be managed by the session bean object itself.

By: Paul Allen and Joseph Bambara : 2008-08-25

Description: Session beans can either be stateful or stateless. With stateful beans, the EJB container saves internal bean data during and in between method calls on the client's behalf. With stateless beans, the clients may call any available instance of an instantiated bean for as long as the EJB container has the ability to pool stateless beans. This enables the number of instantiations of a bean to be reduced, thereby reducing required resources.

By: Paul Allen and Joseph Bambara : 2008-08-25

Description: To simplify the development process for the enterprise bean provider, the implementation of the security infrastructure is left to the EJB container provider and the task of defining security policies is left to the bean deployer. By avoiding putting hard-coded security policies inside bean code, EJB applications gain flexibility when configuring and reconfiguring security policies for complex enterprise applications. Applications also gain portability across different EJB servers that may use different security mechanisms.

By: Priya : 2007-10-07

Description: EJB is a Java API specification that provides a component architecture for the development and deployment of distributed business objects, but many Java programmers use EJB only for its database access and Java object-persistence capabilities. If your application is highly transactional, requires high availability, and is likely to have many concurrent users, you might want to consider using EJB.

By: aathishankaran : 2007-02-20

Description: Enterprise Java Bean (EJB) is a Server Component Model for Java and is a specification for creating server side, scalable, transactional, multi-user and secure enterprise level applications.

By: aathishankaran : 2007-02-20

Description: To develop Enterprise Java Beans, it consists of four steps they are:

By: aathishankaran : 2007-02-20

Description: Enterprise Java Beans is a server side component. Enterprise Java