EJB3.1 defines enterprise beans as server-side components that encapsulate business logic. The main types of enterprise beans are session beans, message-driven beans, and entity beans. Session beans are further divided into stateless, stateful, and singleton beans. Enterprise beans provide benefits such as portability, transaction management, and scalability.
With the official release of Java EE 6 in December 2009 a new version of the Enterprise JavaBeans specification also saw the light. Enterprise JavaBeans is an architecture for the development and deployment of component-based business applications. Applications written using the Enterprise JavaBeans architecture are scalable, transactional, and concurrent.
While a lot of faithful EJB developer's have been scared away from the specification and some of its unfortunate implementations in the past five years, EJB 3.1 has all the ingredients that make for a successful lightweight component based implementation. At last a decent implementation of a server-side component framework as part of the Java EE specification. This no longer makes you dependent on rebel frameworks such as the Spring framework.
EJB 3.1 continues down the path where EJB 3.0 left us off. The purpose of the Enterprise JavaBeans 3.1 specification is to further simplify the EJB architecture by reducing its complexity from the developer's point of view, while also adding new functionality in response to the needs of the community. Although the Java Persistence API was developed within EJB 3.0, it now evolves under a separate JSR rather than within EJB 3.1 and will therefore not be covered in this presentation.
This presentation will mainly focus on the new features introduced by EJB 3.1 and the basics of EJB are only covered very briefly. Topics covered include: EJB Lite, simple packaging, no-interface local view, portable JNDI names, Embeddable API, Startup/shutdown callbacks, Singleton beans, the new and improved timer and scheduler component, Async invocations, and REST integration.
With the official release of Java EE 6 in December 2009 a new version of the Enterprise JavaBeans specification also saw the light. Enterprise JavaBeans is an architecture for the development and deployment of component-based business applications. Applications written using the Enterprise JavaBeans architecture are scalable, transactional, and concurrent.
While a lot of faithful EJB developer's have been scared away from the specification and some of its unfortunate implementations in the past five years, EJB 3.1 has all the ingredients that make for a successful lightweight component based implementation. At last a decent implementation of a server-side component framework as part of the Java EE specification. This no longer makes you dependent on rebel frameworks such as the Spring framework.
EJB 3.1 continues down the path where EJB 3.0 left us off. The purpose of the Enterprise JavaBeans 3.1 specification is to further simplify the EJB architecture by reducing its complexity from the developer's point of view, while also adding new functionality in response to the needs of the community. Although the Java Persistence API was developed within EJB 3.0, it now evolves under a separate JSR rather than within EJB 3.1 and will therefore not be covered in this presentation.
This presentation will mainly focus on the new features introduced by EJB 3.1 and the basics of EJB are only covered very briefly. Topics covered include: EJB Lite, simple packaging, no-interface local view, portable JNDI names, Embeddable API, Startup/shutdown callbacks, Singleton beans, the new and improved timer and scheduler component, Async invocations, and REST integration.
Overview of EJB technology.
Enterprise Java Beans (EJB) is a server-side component technology for Java EE based systems (JEE).
Beans are business logic components that implement a standard interface through which the bean is hooked into the bean container (= runtime object for bean).
A Java class implementing one of the standard bean interfaces is an Enterprise Java Bean. Beans can be accessed remotely, usually from a client tier.
The EJB standard was developed to provide a common framework for solving recurring problems in business application development like persistence, transactions,
security and runtime and lifecycle management. The EJB standard evolved greatly over time. EJB version 1 and 2 were complex and required to implement many interfaces
and exception handling in EJBs. EJB version 3 brought great simplifications and did away with interfaces by replacing these with annotations which provide greater flexibility while keeping complexity low. EJBs come in 3 different flavors: Stateless and stateful session beans and message driven beans. Entity beans of EJB version 1 and 2 were replaced by the Java Persistence API in EJB version 3.
Quontra Solutions is leading provider of IT career advice, Training and consulting services for IT Professional and corporates across USA. We train individuals or Corporate via online or class Room training in all IT tools and Technologies.
We always strive to bring out innovative methods along with the traditional teaching techniques which enhance the overall experience of the students and teachers to extract the return on Investments, high efficiency and scalability.
The company’s architecture is based on the insights from the marketplace, business analytics and strategies keeping intact the fundamental principles in mind, helps us to compete and win in today’s environment without changing any quality in training.
The support, service and training provided by Quontra solutions for various customers assures a “stay up to date” easy transition from previous to current in terms of technology. Our advertisers and promoters are none other than the clients you have been associated with us for their training needs. We improve our training programs from the feedback from the students.
Email Id : info@quontrasolutions.co.uk
Website: http://www.quontrasolutions.co.uk
Enterprise Java Beans (EJB) is a platform for building portable, reusable, and scalable business applications using the Java programming language.
EJB allows application developers to focus on building business logic without having to spend time on building infrastructure code for services such as transactions, security, automated persistence, and so on.
This presentation introduces EJB 3.0 concepts with code examples.
Overview of EJB technology.
Enterprise Java Beans (EJB) is a server-side component technology for Java EE based systems (JEE).
Beans are business logic components that implement a standard interface through which the bean is hooked into the bean container (= runtime object for bean).
A Java class implementing one of the standard bean interfaces is an Enterprise Java Bean. Beans can be accessed remotely, usually from a client tier.
The EJB standard was developed to provide a common framework for solving recurring problems in business application development like persistence, transactions,
security and runtime and lifecycle management. The EJB standard evolved greatly over time. EJB version 1 and 2 were complex and required to implement many interfaces
and exception handling in EJBs. EJB version 3 brought great simplifications and did away with interfaces by replacing these with annotations which provide greater flexibility while keeping complexity low. EJBs come in 3 different flavors: Stateless and stateful session beans and message driven beans. Entity beans of EJB version 1 and 2 were replaced by the Java Persistence API in EJB version 3.
Quontra Solutions is leading provider of IT career advice, Training and consulting services for IT Professional and corporates across USA. We train individuals or Corporate via online or class Room training in all IT tools and Technologies.
We always strive to bring out innovative methods along with the traditional teaching techniques which enhance the overall experience of the students and teachers to extract the return on Investments, high efficiency and scalability.
The company’s architecture is based on the insights from the marketplace, business analytics and strategies keeping intact the fundamental principles in mind, helps us to compete and win in today’s environment without changing any quality in training.
The support, service and training provided by Quontra solutions for various customers assures a “stay up to date” easy transition from previous to current in terms of technology. Our advertisers and promoters are none other than the clients you have been associated with us for their training needs. We improve our training programs from the feedback from the students.
Email Id : info@quontrasolutions.co.uk
Website: http://www.quontrasolutions.co.uk
Enterprise Java Beans (EJB) is a platform for building portable, reusable, and scalable business applications using the Java programming language.
EJB allows application developers to focus on building business logic without having to spend time on building infrastructure code for services such as transactions, security, automated persistence, and so on.
This presentation introduces EJB 3.0 concepts with code examples.
CDI Best Practices with Real-Life Examples - TUT3287Ahmad Gohar
As the adoption of Contexts and Dependency Injection (CDI) for Java EE API grows, it is important to understand how to use CDI effectively to maximize the benefits of using a loosely coupled, type-safe, annotation-driven dependency injection solution. This session outlines the best practices for using CDI, such as annotations versus XML, @Named as a qualifier, qualifier type safety versus verbosity, effective use of producers/disposers, using scopes properly, best practices for using conversations, defining effective stereotypes, interceptors versus decorators, static versus dynamic injection/lookup, CDI versus Java EE resource injection, using CDI with EJB 3.1, CDI/JSF 2 integration patterns, and CDI/JPA 2 usage patterns.
Modern application frameworks like Spring promote a POJO-based programming model, and POJOs are inherently easy to unit test. But how can we effectively integration test our application outside the container while still getting as close to a production-like environment as possible? This session will show attendees how to approximate a target production environment using the Spring TestContext Framework to drive fast, repeatable, "out-of-container" integration tests. To simulate a live system, the session will cover open source integration testing techniques such as the use of in-memory databases, JMS providers, and Servlet containers as well as mock SMTP and FTP servers.
WebLogic Stability; Detect and Analyse Stuck ThreadsMaarten Smeets
Stuck threads are a major cause for stability issues of WebLogic Server environments. Often people in operations and development who are confronted with stuck threads, are at a loss what to do. In this presentation we will talk about what stuck threads actually are and how you can detect them. We will elaborate on how you can get to the root cause of a stuck thread and which tools can help you with that. In order to reduce the impact of having stuck threads in an application, we will talk about using workmanagers. In order to prevent stuck threads we will illustrate several patterns which can be implemented in infrastructure and applications. Next time you see a stuck thread, you will know what to do!
Real world RESTful service development problems and solutionsMasoud Kalali
This session is a deep dive as well as an interactive discussion on design principles, considerations, lessons learned from mistakes that can be taken into account when developing RESTful services. It will cover a variety of topics from Designing of RESTful resources, Versioning,Exception Handling, Caching, Validation, Security, Rate limiting, HATEOAS, Testing and Documentation. This talk will walk through and compare the different REST API provided by companies like Twitter, Paypal, Google, Stripe and more we can learn the good, the bad and ugly. So join me in this talk to build high quality applications that can be highly scalable, available and reliable. Summary: Learn all you ever wanted to learn about RESTful services development challenges in large scale applications Outline: This session is a deep dive as well as an interactive discussion on design principles, considerations, lessons learned from mistakes that can be taken into account when developing RESTful services. It will cover a variety of topics from Designing of RESTful resources, Versioning, Exception Handling, Caching, Validation, Security, Rate limiting, HATEOAS, Testing and Documentation. This talk will walk through and compare the different REST API provided by companies like Twitter, Paypal, Google, Stripe and more we can learn the good, the bad and ugly. So join me in this talk to build high quality applications that can be highly scalable, available and reliable.
PPT contains all the data related to J2EE Servlet and JDBC.
Please see the content and share it.
The ppt includes database drivers and servlet related content.
2. What Is an Enterprise Bean
• is a server-side component that encapsulates the business logic of an application.
• Beneits of Enterprise Beans
– EJB container provides system-level services to enterprise beans, the bean
developer can concentrate on solving business problems.
– the beans rather than the clients contain the application’s business logic, the
client developer can focus on the presentation of the client.
– , because enterprise beans are portable components, the application
assembler can build new applications from existing beans.
3. When to Use Enterprise Beans
• The application must be scalable.
• Transactions must ensure data integrity.
• The application will have a variety of clients
4. Types of Enterprise Beans
• Session
– Performs a task for a client; optionally may
implement a web service
– Stateless, Statefull, Singleton
• Message-Driven
– Acts as a listener for a particular messaging
type, such as the Java Message Service API
5. What Is a Session Bean?
• A session bean encapsulates business logic that can be invoked
programmatically by a client over local, remote, or web service client
views.
• In a stateful session bean, the instance variables represent the state of a
unique client/bean session.
• A stateless session bean does not maintain a conversational state with the client.
When a client invokes the methods of a stateless bean, the bean’s instance
variables may contain a state specific to that client but only for the duration of the
invocation.
• A stateless session bean can implement a web service, but a stateful session bean
cannot.
• A singleton session bean is instantiated once per application and exists for the
lifecycle of the application
6. When to Use Session Beans
• Stateful session beans
– The bean’s state represents the interaction between the bean
and a specific client.
– To hold information about the client across method invocations.
• Stateless session bean
– has no data for a specific client.
– performs a generic task for all clients.
– implements a web service.
• Singleton session
– state needs to be shared across the application.
– to be accessed by multiple threads concurrently.
– to perform tasks upon application startup and shutdown.
– implements a web service.
7. Stateful Session Beans
• the instance variables represent the state of a unique client/bean session
• the client interacts with its bean
• often called the conversational state.
8. Life Cycle
• @PostConstruct
– to initialize any resources such as database connection, files etc
required for the bean.
• @PreDestroy
– to release or close any resources used by the bean.
• Rules for @PostConstruct and @PreDestroy
– method signature must return a void and take no arguments.
– method should not throw Checked Exception
– can have access modifiers
– may be FINAL
9. Lifecycle
• Passivation and Activation of Stateful Session Bean
– The transfer from the working set to secondary storage is called instance passivation. In contrast called
activation.
• Conditions for Passivation
– When the instance is not in a transaction.
– with an extended persistence context
– All the entities in the persistence context are serializable.
– The EntityManager is serializable.
• @PrePassivate
– Invoked before the stateful session bean is passivated.
– can be used to release or close any resources used by the bean.
• @PostActivate
– after the stateful session bean is activated.
– to re-initialize any resources such as database connection, files etc which are closed before passivation.
• Rules for @PostActivate and @PrePassivate
– signature must return a void and take no arguments
– can have access modifiers
– cannot be STATIC or FINAL
11. Lifecycle
• The Lifecycle of a Singleton Bean
– Same as Stateless bean
• Initializing Singleton Session Beans
@Startup
@Singleton
public class StatusBean {
private String status;
@PostConstruct
void init {
status = "Ready";
}
….
}
12. • Managing Concurrent Access in a Singleton
Session Bean
– container-managed concurrency and bean-managed
concurrency.
@Lock(LockType.READ)
@Lock(LockType.WRITE)
@AccessTimeout
• Bean-Managed Concurrency
– is responsible for ensuring that the state of the
singleton is synchronized across all clients
13. Web Service
• annotated either the javax.jws.WebService or
the javax.jws.WebServiceProvider
• must be annotated with javax.jws.WebMethod
• exposed to web service clients must have
JAXB-compatible parameters and return type
• must have a default public constructor.
• must be annotated @Stateless.
14. Timer Service
• Creating Programmatic Timers
– @Schedule or @Schedules
@Schedule(dayOfWeek="Sun", hour="0")
public void cleanupWeekData() { ... }
@Schedules ({
@Schedule(dayOfMonth="Last"),
@Schedule(dayOfWeek="Fri", hour="23")
})
• Canceling and Saving Timers
– Timers can be cancelled by the following events.
– When a single-event timer expires, the EJB container calls the associated timeout
method and then cancels the timer.
– When the bean invokes the cancel method of the Timer interface, the container
cancels the timer.
15. Timers
• Canceling and Saving Timers
– When a single-event timer expires, the EJB
container calls the associated timeout method
and then cancels the timer.
– When the bean invokes the cancel method of the
Timer interface, the container cancels the timer.
16. Message-Driven bean
• An application client that sends several messages to a queue.
• A message-driven bean that asynchronously receives and processes
the messages that are sent to the queue
• The client starts by injecting the connection factory and queue
resources:
• the client creates the connection, session, and message producer:
17. MDB
• The Message-Driven Bean Class
– must be annotated with the @MessageDriven
– must be defined as public
– cannot be defined as abstract or final.
– a public constructor with no arguments.
– must not define the finalize method.
– implement the message listener interface for the message type it supports.
– @MessageDriven annotation typically contains a mappedName element that specifies the
JNDI name of the destination from which the bean will consume messages
• onMessage Method
– onMessage method of the MessageListener interface
– The method must be declared as public.
– The method must not be declared as final or static.
– The return type must be void.
– The method must have a single argument of type javax.jms.Message.