同学笔记:OracleAS 10g(9.0.4) Concepts

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[B]Oracle AS TopLink[/B]
  这个在Developer's Day中听过了.也大概明白其作用.不想多看.
  但很明显Oracle在此处花了重笔墨.偶就多贴几张图吧.
  Figure 2–6 TopLink Components in the Development Cycle

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Figure 2–7 The OracleAS TopLink Mapping Workbench in a TopLink Environment

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Figure 2–8 OracleAS TopLink Application Components

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Figure 2–9 OracleAS TopLink Metadata

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[B]Oracle JDeveloper[/B]
这段和偶的工作实在末有啥关系,pass.




[B]Oracle AS Web Services[/B]
标准: 允许离散的业务进程在Internet上自说明,允许其它服务定位和调用它们,并返回相应的信息.
    ■ Expose and describes itself
    ■ Allows other services to locate it on the Web
    ■ Can be invoked
    ■ Returns a response

[B]Oracle AS Web Services Architecture[/B]
   Oracle AS Web Services作为Servlets运行在OC4J Servlet Container之中.
   Oracle AS Web Services support both Remote Procedure Call(RPC) style exchange and message oriented, or Document Style,exchange.
   它支持的Web Services包括Java Classes,stateless session EJBs,和stateless PL/SQL stored procedures.
   它支持的Document Style Web Services包括Java Class Document Style Web Services和JMS Documnet Style Web Services.
   图Figure 2–10 Oracle AS Web Services Architecture较为清晰地说明了这种架构.

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[B]Oracle AS Web Services Features[/B]
先说Oracle AS Web Services的开发特性
    ■ Developtment Environment
    ■ Developtment Tools and Wizards
    ■ Automatically Generates WSDL(Web Services Description Language)
    ■ Registration,Publishin,and Discovery
    ■ Developer Simplicity
    ■ Business Logic Reuse
    ■ Common Runtime Services

再说Oracle AS Web Services部署和管理特性
    ■ Packaging and Assembly(生成J2EE .ear文件)
    ■ Deployment
    ■ Register Web Service
    ■ Browse the UDDI Registry
    ■ Monitoring and Administration(measured by up time,CPU consumption,memory consumption).

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[B]Oracle AS Forms Services[/B]
   Oracle Form应用是集成图形界面,支持强大的数据校验.Form Developers可以快速开发出功能强大的应用.
   而现在,通过Oracle AS Form Services技术,将此功能在browser中实现(就是运行在browser的applet中).
   Oracle AS Forms Services与传统的HTML form应用相似.它将form application部署到Web环境的Java client中去.它会自动优化类的下载,网络通信,并可与Oracle数据库互动. 应用自动在多个服务器间作load-balance,很容易根据请求数量作出调整.
   Oracle AS Forms Services包含四种组件:
   ■ Forms Servlet
     用于,在用户启动Forms application时,建立初始连接.它将含有Forms Client applet的HTML文件返回给client.
   ■ Forms Client Applet
     它是个运行在browser中的Java applet. It provides the user interface for the corresponding Forms Runtime Process.
   ■ Forms Listener Servlet
     它运行在OC4J Servlet Container中. 它会管理Forms Runtime Process的lifecycle和与运行进程的网络连接.
   ■ Forms Runtime Process
     它是运行在Oracle AS instance中的一个process. 这个process维护client applet和database间的连接.

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[B]Oracle AS Forms Services Arcitecture(及Client-Server互动步骤)[/B]
当client请求Oracle AS Forms应用时,client,server的处理步骤如下:
1. 用户启动browser,并输入相应的URL请求Forms Application.
2. HTTP Listener解释这个URL并生成一个含有<APPLET>tag(说明页面中需要Forms Java Client)的HTML页面.URL调用Forms Servlet来动态地生成此HTML.
3. client接收到HTML文件.文件中提供了必要的查找用于生成Form Java Client的类文件的信息,以及其它Forms session所需的参数(例如:login信息).
4. Browser下载Forms Java Client,Java applet开始运行了.
5. Forms Java Client applet通过HTTP Listener向Forms Listener Servlet发送开始Forms session的request.
6. 接收到Forms Java Client的连接请求后,Forms Listener Servlet启动一个新的Forms Runtime process来向client提供服务.
7. Forms Runtime process允许客户端载入HTML文件中指定的modules和form所需的其它libraries和menus.Form Java Client和Forms Runtime process之间的通信不需要Forms Listener Servlet参与.
8. Applet提示用户输入database login information,正确输入后,就可与database server建立起连接.
9. 用户现在可以使用Forms application了.

图Figure 2–11 Oracle Application Server Forms Services Request Flow显示了整个流程.(没有Database SG做得好,都没有标出步骤编号)

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[B]Oracle AS Forms Services Features[/B]
  robust and standard.
1. Automatic Internet Scalability and High Performance
   Oracle AS Forms Services可以将Oracle Form application部署到多层环境中去,是个优化的结构.它提供了现成的功能和本地服务来保障Forms application可在任何网络上自动调整.Oracle AS Forms Services还允许不改代码的情况下将已存在的Forms application重新部署到Internet上去的功能.

■ Native Services and Out-of-the-Box Functionality
就是说Oracle AS Forms的开发,部署不需要涉及N层应用和不同网络架构等很底层的东西，因为Oracle AS提供了out-of-the-box的功能.这些native的服务有:record caching/record locking/database management/exception handling/load balancing.
这段有个单词out-of-the-box,找人译了一下:现成的.
  
■ Application Server Integration
Oracle AS Forms Services使用了Oracle AS Infrastructure,部署到Oracle AS for J2EE(OC4J).不需写代码就可使用Oracle AS Single Sign-On(OSSO).强大的集中管理/监控/诊断功能.

■ Network Traffic Optimizations
因为可能部署在Internet上,所以Oracle AS Forms Services对网络流量(主要是通过减少client-server之间所需通信的次数来达到)和数据库响应时间(这一点偶很怀疑的说)作了优化.

■ HTTP/HTTPS Support
可在Internet/Intranet上部署,可穿过防火墙.

■ Load Management
Oracle AS Forms Services是基于标准Servlet的. 因此可使用标准的load-balancing技术,如hardware load balancing,reverse proxy servers.(也可同时解决single point of failure的问题)

2. Open Access to Internet Standards
(这段不多看.对偶末有啥用)
■ Server-Side Openness
■ Client-Side Openness

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[B]Oracle XML Developer Kit[/B]
XML的功能不多说了.眼下ETL工具也很多用此来定义数据.
Oracle AS有Oracle XML Developer Kit(XDK)来开发使用XML的应用.
文中粗略地介绍了各XML的功能及API(都是W3C-World Wide Web Consortium的东东).不多看,只求记些新名词. Document Type Definitions(DTDs)
■ XML and XSLT Parsers
1. Document Object Model(DOM) APIs: 用于将XML文件解析成"树形结构的对象".
2. Simple APIs for XML(SAX）APIs: 在解析XML时,会通知应用程序处理事件或特殊数据.
3. Namespace APIs:  使用Uniform Resource Identifier(URI)来唯一标识资源.
4. Parser APIs: 解析XML文件.
5. XSLT APIs: 根据stylesheet来转换(实际上也是取出其中的数据)XML文件.(允许caching stylesheets和DTDs)

■ XML Schema Processors
与W3C XML Schema Working Drafts的Structures和Datatypes sections兼容.

■ XML Class Generators
根据DTD或XML schema definitions,将XML生成成Java或C++类.

■ XSQL Servlet
可从XML文件中查询出结果集.可将查出的结果传给Web Server或存入数据库中.

■ XML Transviewer Beans
可以解析,查看XML的Java Beans.