EJB 3.0实战第二版：深入解析与应用

需积分: 5 146 浏览量更新于2024-07-19 收藏 15.93MB PDF 举报

"EJB 3.0 in Action 2nd Edition 是一本专注于EJB 3.0技术的英文电子书，具有书签功能并可检索。由Debu Panda、Reza Rahman、Ryan Cuprak和Michael Remijan共同编写，获得了业界的好评，包括来自JavaRanch.com的Jeanne Boyarsky、Oracle Canada的King Y. Wang以及Expert Group Member JSR243 Java Data Objects的Awais Bajwa等人的推荐。本书以其易读性、实用性和趣味性受到赞誉，适合广泛的技术读者群体，不仅概述了EJB 3.0规范，还提供了大量实践指导。" EJB（Enterprise JavaBeans）是Java平台企业版（Java EE）的核心组件之一，用于构建可部署在服务器端的企业级应用程序。EJB 3.0是其一个重要版本，引入了诸多改进，使得开发过程更为简洁，降低了学习曲线。本书记载了EJB 3.0的主要特性，包括： 1. **Java Persistence API (JPA)**：EJB 3.0引入了JPA作为标准的持久化框架，使得对象关系映射（ORM）变得更加简单。JPA允许开发者用Java对象模型来操作数据库，减少了对SQL的依赖。 2. **实体Bean（Entity Beans）**：EJB 3.0中的实体Bean采用了注解驱动的方式，无需XML配置，简化了对象到数据库的映射。实体Bean可以是容器管理的持久化（CMP），也可以是bean管理的持久化（BMP）。 3. **会话Bean（Session Beans）**：会话Bean用于处理业务逻辑，EJB 3.0允许使用无状态会话Bean和有状态会话Bean，其中无状态会话Bean通常用于执行一次性任务，而有状态会话Bean可以跟踪用户会话。 4. **消息驱动Bean（Message-Driven Beans, MDB）**：MDB用于处理JMS（Java Message Service）消息，实现异步处理。 5. **拦截器（Interceptors）**：拦截器是EJB 3.0的一个新特性，允许在方法调用前后插入自定义行为，如日志、性能监控等。 6. **事务管理（Transactions）**：EJB 3.0提供自动事务管理，支持不同级别的事务隔离和恢复策略。 7. **安全性（Security）**：EJB 3.0通过角色基于的安全性（RBAC）来控制对Bean的访问，可以定义不同的角色和权限。 8. **性能优化**：书中会讨论如何优化EJB应用，包括缓存策略、批处理操作和查询优化等。本书以一个简单而精心设计的案例研究为引导，逐步深入EJB 3.0的复杂概念，并通过实际示例进行解释，帮助读者理解和掌握EJB 3.0的各个方面。无论你是初学者还是经验丰富的开发者，都能从中获益，提升你的企业级Java开发能力。

preface

In its early days,

EJB

was inspired by the distributed computing ideas of technologies

such as

CORBA

and was intended to add scalability to server-side applications.

EJB

and

J2EE

enjoyed some of the greatest buzz in the industry during the dot.com boom.

The initial goal for

EJB

was to provide a simpler alternative to

CORBA

through the

benefits of a standard development framework and reusable components. By the time

EJB

2 was released, it became apparent that the

EJB

framework could become the new

standard for server-side development. The framework provided Enterprise developers

with everything they needed—remoting, transaction management, security, state main-

tenance, persistence, and web services—but it was heavyweight, requiring developers

to focus more on the framework itself than on the requirements of their business

applications. Because

EJB

was loaded with more features, its inventors failed to address

its growing complexity.

As the community became disenchanted with the limitations of

EJB

2, innovative

open source tools emerged. These tools were signs of the increasing discontent with

the complexities of Java

. Though well-intentioned, these tools made Enterprise

development even more complex since they deviated from the standards of the appli-

cation server they were to run in. It was time for the Java Community Process (

JCP

)

and expert groups to work on the simplification of Java

development. That was the

sole motivation behind Java

5 and the goal of the

EJB

3 expert group.

For a technology with a wide deployment base, the changes that came with

EJB

were nothing short of stunning.

EJB

3 successfully melds innovative techniques to

make component development as easy as possible. These techniques include the use

www.finebook.ir

PREFACE

xvi

of annotations, metadata programming, dependency injection, AspectJ-like intercep-

tors, and intelligent defaulting. The heavyweight inheritance-based programming

model was abandoned in favor of Plain Old Java Object (

POJO

) programming, and

the verbose

XML

descriptor was now out of the developer’s way.

The changes to the persistence model were particularly dramatic.

EJB

3 left behind

the flawed

EJB

2 Entity Beans model in favor of the lightweight Java Persistence

API

(

JPA

). Unlike Entity Beans,

JPA

is not container-based. It has more in common with

open source object relational mapping (

ORM

) tools that emerged in the community

in response to Entity Beans complexity.

JPA

can be used either inside or outside a Java

Enterprise server and is now the de facto persistence standard for Java. Its Java Persis-

tence Query Language (

JPQL

) standardizes object relational queries but also supports

native

SQL

queries if the need arises.

The changes made in

EJB

3 have been well received in the Java community. Its sim-

plified specification has led to its wide adoption in new projects. More and more com-

panies are giving the once “ugly”

EJB

technology another look and they like what they

see. With the release of

EJB

3.2, the adoption will continue to grow.

EJB

3.2 has made

support for

EJB

2 optional so that older technology can finally be sunset and innova-

tions in

EJB

3 can continue to grow.

EJB

3.2 has also seen major enhancements to

message-driven beans (

MDB

s), making messaging much easier.

EJB

3.2 made improve-

ments to stateful session bean passivation and session bean local interfaces, as well as

dramatic improvements to the timer services. All this and more await you in

EJB

3.2.

Since

EJB

POJO

-based, every Java developer can easily become an

EJB

developer.

Simple annotations give your business logic safe transaction management, security,

and exposure as web services for easy interoperability in your company. We strive to

keep our book different from other books on

EJB

by providing practical examples,

best practices, and tips for performance tuning. We highlight what’s new in the

EJB

3.2

specification, which gives you more tools for your development. We hope this revised

edition will help you to quickly learn how to use

EJB

3 effectively in your next Enter-

prise application.

www.finebook.ir

ACKNOWLEDGMENTS

xviii

EBU

ANDA

I’d like to thank my wife, Renuka, for her immense support and continuous encour-

agement and for her patience with all the late nights, early mornings, and weekends

that I spent on the first edition of the book. I’d also like to thank my kids, Nistha and

Nisheet, who had to share their bapa with the computer during that time.

Many thanks to my coauthors Reza Rahman, Ryan Cuprak, and Michael Remijan,

who worked hard on the second edition of the book.

EZA

AHMAN

A journey of a thousand miles begins with a single step.

—Lao-tzu

When I decided to take on writing the first edition of this book, I don’t think any of

the authors were certain how successful the book was going to be or where it might

take us personally. Today I have the luxury of hindsight in saying the book has been a

resounding success and that writing it was the first step of a whirlwind journey over the

past few years that I could have never foreseen. I must confess I continue to enjoy

every minute of it. Since finishing the first edition, I’ve become increasingly more

engaged with the Java community. I’ve contributed to various Java

expert groups,

including the

EJB

expert group, had the once-in-a-lifetime opportunity to write an

open source

EJB

container almost from scratch, and now find myself at the forefront

of the Java

evangelism team at SunOracle.

One casualty of all of this has been my own personal bandwidth, which was more

abundant when I wrote the first edition. This is a large part of why we had to skip a

Java

6 and

EJB

3.1 edition of this book. I do think it’s all for the best since Java

7 is

an even stronger and more compelling platform, as this edition will demonstrate. I’m

extremely grateful to Michael and Ryan for taking ownership of the book and being

instrumental in producing a worthy second edition. I’m also grateful to the many

folks like you in the Java

community that I’ve had the privilege to serve and work

with. Lastly, I’m ever thankful to my wife Nicole and daughter Zehra for allowing me

to pursue my passion without reservation. And so the journey continues.

YAN

UPRAK

Writing this book would not have been possible without the support of family and

friends. I’d especially like to thank the love of my life, Elsa, who has supported and

encouraged me throughout the long, arduous process and the many long nights I was

hunched over the computer. Finally, I’d like to thank Reza for recruiting me to this

project and encouraging me to take a second look at Java

many years ago.

ICHAEL

EMIJAN

My wonderful wife Kelly and my daughter Sophia are the first people I need to thank

when it comes to writing this book. It’s one of many adventures we’ve shared together,

www.finebook.ir

剩余560页未读，继续阅读

titi2018

粉丝: 0
资源: 11

EJB 3.0实战第二版：深入解析与应用

EJB 3.0 in action

EJB 3.0 in Action

ejb3.0项目框架代码

ejb3.0项目代码结构

ejb3.0实现 带有事务提交回滚的demo

ejb-jar.xml

TomEE required to support EAR/EJB deployment

新建ejb3项目websphere

Default EJB interceptors should be declared in "ejb-jar.xml"

ejb-.xml应该怎么写

最新资源

ejb3.0实现带有事务提交回滚的demo