J2EE教程.ppt

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1、声明,本课件仅用于北京航空航天大学计算机学院的教学；本课件修改采用了一些网络资源（论文、研究报告、技术报告等），在采用的时候并没有准确标注引用信息。,J2EE教程第1章 J2EE介绍(What is J2EE?),内容列表,1.1 J2EE的历史1.2 J2EE组成和结构1.3 J2EE容器1.4 J2EE Timeline1.5 J2EE开发者角色1.6 J2EE产品1.7 J2EE应用示例,1.1 J2EE的历史,1.应用模式,C/S两层结构，又称Client/Server或客户/服务器模式服务器通常安装数据库系统。客户端需要安装专用的客户端软件。业务逻辑通常在客户端处理，适用于单机或者小

2、型局域网。典型的例子：数据采集软件（VB+ACCESS）,应用模式：三层结构,表示层+功能层+数据层其特点是在两层结构的基础上加入一个（或多个）中间件层。它将CS体系结构中原本运行于客户端的应用程序移到了中间件层。客户端只负责显示与用户交互的界面及少量的数据处理（如数据合法性检验）工作。,应用模式：三层结构,C/S三层：应用程序客户端+应用服务器+数据库服务器B/S：浏览器+Web服务器+数据库服务器N-Tier：浏览器+应用服务器+数据库服务器基于Windows DNA的实现方案：Browser+(ASPActiveXControl)(COM/COM)ODBC基于J2EE结构的实现方案是：B

3、rowser+(JSPServlet)JavaBeansEJBJDBC,2.Windows History,WindowsHistory 1992-1996,1993:Windows NT Advanced Server 3.1 Microsoft SQL Server,Microsoft Mail 1996:Windows NT Server 4.0 Web server,Internet Information Server(IIS)2.0 component object model(COM)support,WindowsHistory 1998-2000,2000:Windows 20

4、00 Server Family Microsoft Active Directory directory service.Active Server Pages(ASP)COM+component servicesDNA:Distributed interNet Application Architecture,WindowsHistory 2001?,2003:Windows Server 2003.Net,3.CORBA What is it?,Provides interoperability among:Programming LanguagesOperating SystemsSo

5、ftware VendorsNetwork Computers,The Object Management Group(OMG)Founded in 1989The Working Area:Distributed Objects,CORBAHistory 1.0(Oct.1991Dec.1993),CORBA Object model(Core 92)Interface Definition Language(IDL)Mapping from IDL to the C language.the core set of APIs for dynamic request management a

6、nd invocation and Interface Repository.interfaces for the Basic Object Adapter and memory management,CORBAHistory 2.02.3(Aug.96 Jun.99),General Inter-ORB Protocol/Internet Inter-ORB Protocol(GIOP/IIOP)Portable Object Adapter(POA)Collaboration with OLE2/COMMapping from IDL to Java,Cobol,Ada,Smalltalk

7、,C+,CORBA History 2.43.0(Feb.2001?),Java and Internet IntegrationObjects Passable by ValueJava-to-IDL MappingInteroperable Name ServiceAsynchronous Messaging and Quality of Service ControlMinimum,Fault-Tolerant,and Real-Time CORBACORBA components and CORBA scripting,4.Java History 1995-1996,March 23

8、,1995：Java is born.Father:James Goslings,Mother:Sun Microsystems.May 23,1995：Java Technology officially announced in SunWorld.January 23,1996：JDK 1.0 release dayMay 29,1996:First JavaOne developer conference,JavaBeans,Servlets and other technologies announced.December 9,1996：JDK 1.1 beta software re

9、leasedFebruary 18,1997：JDK 1.1 released.,Java History 1997-2001,March 4,1997：Enterprise JavaBeans(EJB)technology announced Java Foundation Classes(JFC)technology included in Java platformJune 2,1999：Java Server Pages(JSP)technology unveiledJune 15,1999：Three editions of Java platform:J2SE,J2EE,J2ME

10、announcedApril 2001：Java 2 Platform,Enterprise Edition(J2EE)SDK 1.3 beta released(EJB 2.0,JSP 1.2,servlet 2.3),Java History 2002-?,January 28,2002：Java Web Services Developer Pack(WSDP),Early Access Release 1December 2002：J2EE 1.4 Beta releasedOctober 1,2004：Tiger(Java 5.0)released!,1.2 J2EE组成和结构,Ja

11、va 2 Platform Enterprise Edition 为开发、部署和管理以服务器为中心的企业应用提供了解决方案。J2EE is End-to-End Solution企业应用的特点用户业务数据物理分布系统复杂处理功能多安全可靠性可管理,J2EE的三层结构,运行于客户机的客户层组件,运行于J2EE服务器上的网络层组件,运行在J2EE服务器上的逻辑层组件,1.J2EE客户端,网络浏览器：网络客户端又称为瘦客户。动态网页包含各种标记语言（HTML,XML等）小程序：网页可以包含小程序。应用客户端：J2EE应用客户端运行在客户上，它为用户处理任务提供了比标记语言丰富的接口。,2.网络组件,

12、J2EE网络组件可以是servlet或jsp。Servlet是java类，它能动态处理请求及响应。Jsp页面是基于文档的，能像servlet一样执行。网络层可以包含JavaBean组件来管理用户输入、发送输入到逻辑层的EJB以处理。静态HTML页面及applets域网络组件绑在一起，但J2EE规范没有认为这些为网络组件。,What is Servlet?,扩展了HTTP服务器功能的Java objects能够动态产生(页面)内容Better alternative to CGI,NSAPI,ISAPI,etc.EfficientPlatform and server independentSe

13、ssion management,What is JSP Technology?,基于Servlet技术Extensible via custom tagsEnables separation of business logic from presentationBusiness logic is implemented as Java Beans or custom tagsPresentation is in the form of HTML or XML/XSLT,3.业务逻辑组件,业务逻辑代码是解决特定业务领域的需求的程序代码，在J2EE中，通常指EJB。,What is EJB Te

14、chnology?,J2EE的基石服务器端的组件共有三种EJB：会话(session)bean：代表短暂的与客户的会话，当客户结束执行时，会话bean及它的数据就消失了实体(entity)bean：实体bean代表存储在数据库的表，如果客户结束程序或服务器关闭，潜在的服务方法会将数据存储。消息驱动(message-driven)bean。,1.3 J2EE容器,瘦客户端的多层应用程序总是很难开发，因为它包括各个层的事务处理、状态管理、多线程、资源池和其他复杂底层细节等等的错综复杂的编码。基于组件和平台独立的J2EE平台使J2EE应用程序容易开发商业逻辑被封装在可重用的组件（EJB）中。J2EE

15、服务器以容器的形式为所有组件提供底层服务，因此你不必再为这些底层服务二伤脑筋，而可以专注于解决商业问题。,Containers in Java EJB容器：管理J2EE应用程序中企业Bean的运行。企业Bean和它们的容器在J2EE服务其中运行Web容器：管理J2EE应用程序中JSP页面和Servlet组件的运行。Web组件和容器也在J2EE服务其中运行。Application client container（应用程序客户端容器）：管理应用程序客户端组件的运行。应用程序客户端和它的容器运行在客户机。Applet container（Applet容器）：管理Applet的运行。由在客户端运行的

16、浏览器和Java插件组成。,J2EE Server（J2EE服务器）是J2EE产品的运行时服务部分。一个J2EE服务器提供EJB容器（EJB Container）和Web容器（Web Container）。,J2EE Containers&Components,What is JNDI Technology?,JNDI=Java Naming and Directory InterfaceJNDI 提供了统一的API，用于访问不同厂家提供的命名服务,JNDI and EJBJNDI plays an important role in the use of EJBs.to locate EJB

17、 remote home interfaces,EJB local home interfaces,Data resources.,What is JDBC Technology?,Java Database ConnectivityJDBC is a Java API for executing SQL statements.JDBC provides a standard API for tool/database developers and makes it possible to write database applications using a pure Java API.JD

18、BC makes it possible to do three things:1.establish a connection with a database2.send SQL statements3.process the results,What is JTA/JTS Technology?,Java Transaction API/Java Transaction Service allows applications to perform distributed transactions,that is,transactions that access and update dat

19、a on two or more networked computer resourcesJTS 对事务分界和事务环境的传播之类的 服务提供支持。JTS 功能由应用程序通过Java Transaction API 访问,What is JavaMail Technology?,The JavaMail API is an optional package(standard extension)for reading,composing,and sending electronic messages.JavaMail API 是一组抽象的API，用于构建基于Java 技术的 电子邮件客户端应用程

20、序 four protocolsSMTPPOPIMAPMIME,What is JAF Technology?,JavaBeans Activation Framework The JAF API provides a framework for handling data in different MIME types,originating in different formats and locations.The JavaMail API makes use of the JAF API,so it must be included as well.,JNDI,J2SE,JMS,RMI

21、/IIOP,JDBC,Database,AppClient,App Client Container,HTTP/HTTPS,J2SE,RMI,J2SE,JNDI,JMS,RMI/IIOP,JDBC,JTA,JavaMail,JAF,JNDI,JMS,RMI/IIOP,JDBC,JTA,JavaMail,JAF,HTTP/HTTPS,Applet Container,Applet,JSP,Servlet,EJB,Web Container,EJB Container,RMI,J2SE,J2EE&Middleware,1.4 J2EE Timeline,1997,2003,1998,1999,20

22、00,2001,2002,(All dates are approximate.Many of these technologies were hyped long before they were actually released.),JMS 1.1,Java 2 SDK,Standard Edition,Servlet,JSP,EJB,RMI/IIOP,JMS,JNDI,JDBC,JavaMail,JAF,JTA,Based on J2SE 1.3 ReleaseIncludes EJB 2.0 specIncreased XML integrationJMS now required,

23、Main theme is Web Services:SOAP,XMLP,UDDI,and more,1.5 J2EE开发者角色,Platform providerContainer providerTools providerComponent providerEJB ProviderWeb Component ProviderApplication assemblerDeployerSystem administrator,1.6 J2EE产品,JBOSSSun Application Server BEA WebLogicIBM WebSphere,1.7 环境和示例,Application ServerJBoss 4.0Examplesj2ee-1_4-doc-tutorial_5.zip可以从下面的网址下载：http:/,参考资料,The J2EE 1.4 Tutorial,Eric Armstrong etc.,Sun Microsystems,2005-12Getting Started with JBoss 4.0,JBoss,2005,The End!,