`
leslin123
  • 浏览: 3209 次
  • 性别: Icon_minigender_1
  • 来自: 北京
最近访客 更多访客>>
社区版块
存档分类
最新评论

Reading Notes:Enterprise JavaBeans, 3.0 Chapter 1. Introduction

阅读更多

Reading  Notes:Enterprise JavaBeans, 3.0 Chapter 1. Introduction

 

1.1. Server-Side Components

 

In business systems, object-oriented languages are used to improve development of GUIs, to simplify access to data, and to encapsulate the business logic.

 

A server-side component model may define an architecture for developing distributed business objects that combines the accessibility of distributed object systems with the fluidity of objectified business logic. Server-side component models are used on middle-tier application servers, which manage the components at runtime and make them available to remote clients. They provide a baseline of functionality that makes it easy to develop distributed business objects and assemble them into business solutions.

Server-side components can also be used to model other aspects of a business system, such as presentation and routing. A Java servlet, for example, is a server-side component that generates HTML and XML data for the presentation layer of a web application (Struts and JSF components are also examples of this type of server-side component). EJB message-driven beans, discussed later in this book, are server-side components that can be used to consume and process asynchronous messages.

 

 

1.2. Persistence and Entity Beans

 

Persistence is a higher-level abstraction above JDBC. The persistence layer maps objects to database storage so that they can be queried, loaded, updated, or removed without having to go through a verbose API such as JDBC.

 

The Java Persistence API defines a way to map regular, plain old Java objects (sometimes referred to as POJOs) to a database . These plain Java objects are called entity beans . Entity beans are like any other Java class, except that they have been mapped, using Java Persistence metadata, to a database. Therefore, they may be inserted and loaded from a database without the developer writing any JDBC connection code or reading from result sets. The Java Persistence API also defines a query language that has features that parallel those in SQL, but is tailored to work with Java objects rather than a raw relational schema.

 

Section 1.3.  Asynchronous Messaging

1.3. Asynchronous Messaging

 

In addition to supporting RMI-based distributed business objects, Enterprise JavaBeans supports asynchronous messaging. An asynchronous messaging system allows two or more applications to exchange information in the form of messages. A message, in this case, is a self-contained package of business data and network routing headers.

 

EJB 3.0 supports asynchronous messaging through the Java Message Service (JMS) and a new component called the message-driven bean . In addition to JMS, message-driven beans can support other synchronous and asynchronous messaging systems.

 

 

1.3.1. Java Message Service

 

1.3.2. Message-Driven Beans and JCA 1.5

The expansion of message-driven beans in EJB 2.1 to other protocols was made possible by the new Java EE Connector Architecture (JCA 1.5) , which defines a portable programming model for interfacing with enterprise information systems.

 

 

1.4. Web Services

 

Web services is often defined in fairly abstract terms, like "a substrate for building distributed applications using software running on different operating systems and devices"[*] or "self-contained, self-describing, modular applications that can be published, located, and invoked across the Web."[ ]

 

 

SOAP 1.1

Simple Object Access Protocol (SOAP) is an XML grammar, developed by Microsoft, IBM, and others, that is currently under the auspices of the W3C. It's an application protocol used in both RPC and asynchronous messaging. SOAP is very flexible and extensible and, unlike its predecessors (DCE RPC, CORBA IIOP, Java RMI-JRMP, and DCOM), it's been endorsed and adopted by just about every major vendor. (If you're not familiar with XML, see Java and XML or XML in a Nutshell , both from O'Reilly.)


WSDL 1.1

The Web Service Description Language (WSDL) is another XML grammar, developed by Microsoft and IBM under the auspices of the W3C. It is an XML-based Interface Definition Language (IDL) that can be used to describe web services, including the kind of message format expected, the Internet protocol used, and the Internet address of the web service.

 

Web services are truly platform-independent. Although Java RMI and CORBA IIOP also claim to be platform-independent, in fact these older technologies require their own platforms.

 

Web services, on the other hand, are not tied to a specific platform like the JVM or to a technology infrastructure like CORBA because they focus on the protocols used to exchange messages SOAP and WSDL and not on the implementation that supports those protocols. In other words, you can build web services on any platform using any programming language any way you please.

 

EJB 3.0 allows enterprise beans to be exposed as web services so that their methods can be invoked by other J2EE applications as well as applications written in other programming languages on a variety of platforms. Web services in EJB 3.0 support both RPC-style and document-style messaging.

 

 

 

 

分享到:
评论

相关推荐

    Enterprise JavaBeans 3.0 5ed.

    Enterprise.JavaBeans.3.0.5th.Edition-OReilly.rar CHM VERSION! SMALL AND FAST. I HAVE TRIED DOWNLOAD THIS BOOK IN CSDN, BUT HAVE NOT FOUND A FULL VERSION(SOME CHINESE VERSION NOT COMPLETE) TO THOSE ...

    Enterprise JavaBeans 3.0

    由于提供的文件内容中并没有实际的关于"Enterprise JavaBeans 3.0"的具体知识点,而只是提到了一本书的标题、描述和标签,并且重复了大量访问网站的信息。为了满足您的要求,我将从标题和描述中提到的《Enterprise ...

    Mastering Enterprise Javabeans 3.0.pdf

    《精通企业JavaBeans 3.0》一书深入探讨了JavaBeans规范的最新版本,即3.0版,这是Java企业级开发中的一个重要里程碑。JavaBeans是Java平台的一部分,主要用于构建可重用的组件,这些组件可以被集成到各种应用程序中...

    Enterprise JavaBeans 3.0 Documentation

    Enterprise JavaBeans(EJB)是Java平台上用于构建可扩展、安全和事务处理的企业级应用程序的框架。EJB 3.0是该技术的一个重大更新,它引入了许多改进,旨在简化开发过程并提高开发者效率。本文档集合是EJB 3.0规范...

    Enterprise JavaBeans 3.0(第5版) chm

    本书主要介绍EJB3.0标准,是获奖权威参考书Enterprise JavaBeans的最新第5版。全书内容主要分为两大部分,第一部分是EJB 3.0的标准技术手册,主要介绍EJB概念、EJB工作原理及使用方法;第二部分是JBoss实践指南,...

    Enterprise JavaBeans 3.0中文版(第5版)

    ### Enterprise JavaBeans 3.0概述 #### 一、企业级应用开发背景 在现代企业级应用开发领域,Java技术一直扮演着至关重要的角色。随着业务需求的不断增长和技术的快速发展,开发人员需要构建出更加灵活、高效且可...

    Enterprise JavaBeans 3.0 中文版

    《企业JavaBeans 3.0 中文版》是Java企业级开发的重要参考资料,它详细介绍了EJB 3.0规范,这是一个里程碑式的版本,极大地简化了EJB的使用,提升了开发效率。本教程旨在帮助开发者深入理解和熟练运用EJB 3.0技术。 ...

    Reilly.Enterprise.JavaBeans.3.1.6th.Edition.2010

    《Reilly.Enterprise.JavaBeans.3.1.6th.Edition.2010》是针对JEE6(Java Enterprise Edition 6)平台的一本权威指南,特别关注于Enterprise JavaBeans(EJB)3.1版本。这本书由Oracle Corporation认证,为希望获得...

    Enterprise JavaBeans 3.0 中文版 (第5版) .pdf 下载.rar

    综上所述,Enterprise JavaBeans 3.0带来了许多创新,如JPA、注解驱动的bean、会话bean和消息驱动bean,以及强大的事务和安全特性。这些特性使得EJB 3.0成为构建企业级Java应用的理想选择,尤其是对于需要处理大规模...

    Wiley.Mastering.Enterprise.JavaBeans.3.0.4th.Edition.Jul.2006

    《Mastering Enterprise JavaBeans 3.0》是Java EE领域的一本权威著作,专注于讲解Java企业版中的核心组件——Enterprise JavaBeans(EJB)3.0版本。这本书由Wiley出版社于2006年7月出版,是第四版,为开发者提供了...

    Mastering Enterprise JavaBeans™ 3.0

    ### 掌握企业级JavaBeans™ 3.0:核心知识点解析 #### 一、企业级JavaBeans(EJB)概述 **企业级JavaBeans (EJB)** 是一种基于Java平台的企业级应用开发模型,主要面向大型分布式系统。EJB 3.0是该技术的一个重要...

    Wiley.Mastering.Enterprise.JavaBeans.3.0.4th.Edition

    《精通企业JavaBeans 3.0 第4版》是一本深度探讨Java企业级开发的权威著作,主要聚焦于Java EE平台中的核心组件——Enterprise JavaBeans(EJB)。这本书旨在帮助开发者掌握EJB 3.0规范,从而在企业级应用开发中实现...

    EJB3.0规范文档.rar

    **企业级JavaBeans(Enterprise JavaBeans,EJB)3.0规范**是Java平台上用于构建分布式、组件化的企业级应用程序的重要框架。EJB3.0是EJB规范的一个重大革新,它极大地简化了开发过程,引入了许多现代软件工程的最佳...

    04.最新EJB 3.0实例教程.rar

    EJB(Enterprise JavaBeans)是Java EE平台中的核心组件,主要用于构建可扩展的、安全的、事务处理的企业级应用。EJB 3.0是其一个重要版本,发布于2006年,带来了许多重大的改进和简化,使得开发过程更为简洁,降低...

    ejb3.0实例教程.rar

    EJB(Enterprise JavaBeans)是Java企业级应用开发的核心组件之一,主要用于构建可复用的、分布式的、事务处理的服务器端应用程序。EJB 3.0是其一个重要的版本,发布于2006年,它在前几个版本的基础上进行了大量的...

    Manning.EJB.3.0.in.Action

    《EJB 3.0 in Action》是一本深入探讨企业级JavaBeans(EJB)3.0版本的专业书籍。EJB是Java平台上的核心组件,用于构建可扩展、可靠的、多用户的企业应用。这本书旨在帮助开发者理解并充分利用EJB 3.0的改进和简化,...

    EJB3.0实例教程.pdf

    **企业级JavaBeans(EJB)3.0详解** 企业级JavaBeans(EJB)是Java平台上用于构建可扩展、安全且事务处理能力强的企业级应用的核心技术。EJB 3.0是其的一个重要版本,引入了许多重大的改进,使得开发更加简单、直观...

    Enterprise JavaBeans, 3.0

    Enterprise JavaBeans™ is the core component technology of the Java Enterprise Edition platform. It is an enterprise infrastructure designed to provide developers with the automatic management of many...

Global site tag (gtag.js) - Google Analytics