??xml version="1.0" encoding="utf-8" standalone="yes"?>蜜桃视频m3u8在线观看,三级无遮挡在线观看,欧美一区二区三区成人http://www.aygfsteel.com/jxhkwhy/category/21011.htmlzh-cnThu, 17 Apr 2008 16:43:45 GMTThu, 17 Apr 2008 16:43:45 GMT60J2EE中两D式提交协议http://www.aygfsteel.com/jxhkwhy/articles/193893.htmlUR?/dc:creator>UR?/author>Thu, 17 Apr 2008 15:48:00 GMThttp://www.aygfsteel.com/jxhkwhy/articles/193893.htmlhttp://www.aygfsteel.com/jxhkwhy/comments/193893.htmlhttp://www.aygfsteel.com/jxhkwhy/articles/193893.html#Feedback0http://www.aygfsteel.com/jxhkwhy/comments/commentRss/193893.htmlhttp://www.aygfsteel.com/jxhkwhy/services/trackbacks/193893.html分布式事物：卌多层的有多个事物加入的事务?br /> 通过使用某种协议q行通信来完成分布式事物Q称ZD式提交
W一个阶D，即预提交Q向事物涉及到的全部资源发送提交前信息.
此时事务涉及到的资源q有最后一ơ机会结束异怺务，如果L一个资源决定异常结束事物，则整个事物被取消Q同时不执行资源的更斎ͼ否则事务会正常进?br /> W二个阶D，提交阶段Q即W一阶段无Q何异常结束时才会发生Q此Ӟ所有的能被定位的和单独控制的资源管理者都执行真正的数据更新


]]>J2EE和桌面程序有什么区?/title><link>http://www.aygfsteel.com/jxhkwhy/articles/193888.html</link><dc:creator>UR?/dc:creator><author>UR?/author><pubDate>Thu, 17 Apr 2008 15:29:00 GMT</pubDate><guid>http://www.aygfsteel.com/jxhkwhy/articles/193888.html</guid><wfw:comment>http://www.aygfsteel.com/jxhkwhy/comments/193888.html</wfw:comment><comments>http://www.aygfsteel.com/jxhkwhy/articles/193888.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.aygfsteel.com/jxhkwhy/comments/commentRss/193888.html</wfw:commentRss><trackback:ping>http://www.aygfsteel.com/jxhkwhy/services/trackbacks/193888.html</trackback:ping><description><![CDATA[  <p><span style="font-size: 9pt; color: blue">Sun</span><span style="font-size: 9pt; color: blue; font-family: 宋体">公司?/span><span style="font-size: 9pt; color: blue">1998</span><span style="font-size: 9pt; color: blue; font-family: 宋体">q发?/span><span style="font-size: 9pt; color: blue">JDK1.2</span><span style="font-size: 9pt; color: blue; font-family: 宋体">版本的时候，使用了新名称</span><span style="font-size: 9pt; color: blue">Java 2 Platform</span><span style="font-size: 9pt; color: blue; font-family: 宋体">Q即“</span><span style="font-size: 9pt; color: blue">Java2</span><span style="font-size: 9pt; color: blue; font-family: 宋体">q_”Q修改后?/span><span style="font-size: 9pt; color: blue">JDK</span><span style="font-size: 9pt; color: blue; font-family: 宋体">UCؓ</span><span style="font-size: 9pt; color: blue">Java 2 Platform Software Develping Kit</span><span style="font-size: 9pt; color: blue; font-family: 宋体">Q即</span><span style="font-size: 9pt; color: blue">J2SDK</span><span style="font-size: 9pt; color: blue; font-family: 宋体">。ƈ分ؓ标准?/span><span style="font-size: 9pt; color: blue">(Standard Edition</span><span style="font-size: 9pt; color: blue; font-family: 宋体">Q?/span><span style="font-size: 9pt; color: blue">J2SE), </span><span style="font-size: 9pt; color: blue; font-family: 宋体">企业?/span><span style="font-size: 9pt; color: blue">(Enterprise Edition</span><span style="font-size: 9pt; color: blue; font-family: 宋体">Q?/span><span style="font-size: 9pt; color: blue">J2EE)</span><span style="font-size: 9pt; color: blue; font-family: 宋体">Q微型版</span><span style="font-size: 9pt; color: blue">(MicroEdition</span><span style="font-size: 9pt; color: blue; font-family: 宋体">Q?/span><span style="font-size: 9pt; color: blue">J2ME)</span><span style="font-size: 9pt; color: blue; font-family: 宋体">?/span></p> <p><span style="font-size: 9pt; color: blue">Standard Edition(</span><span style="font-size: 9pt; color: blue; font-family: 宋体">标准?/span><span style="font-size: 9pt; color: blue">) J2SE </span><span style="font-size: 9pt; color: blue; font-family: 宋体">包含那些构成</span><span style="font-size: 9pt; color: blue">Java</span><span style="font-size: 9pt; color: blue; font-family: 宋体">语言核心的类。比如：数据库连接、接口定义、输?/span><span style="font-size: 9pt; color: blue">/</span><span style="font-size: 9pt; color: blue; font-family: 宋体">输出、网l编E?/span></p> <p><span style="font-size: 9pt; color: blue">Enterprise Edition(</span><span style="font-size: 9pt; color: blue; font-family: 宋体">企业?/span><span style="font-size: 9pt; color: blue">) J2EE </span><span style="font-size: 9pt; color: blue; font-family: 宋体">包含</span><span style="font-size: 9pt; color: blue">J2SE </span><span style="font-size: 9pt; color: blue; font-family: 宋体">中的c，q且q包含用于开发企业应用的类。比如：</span><span style="font-size: 9pt; color: blue">EJB</span><span style="font-size: 9pt; color: blue; font-family: 宋体">?/span><span style="font-size: 9pt; color: blue">servlet</span><span style="font-size: 9pt; color: blue; font-family: 宋体">?/span><span style="font-size: 9pt; color: blue">JSP</span><span style="font-size: 9pt; color: blue; font-family: 宋体">?/span><span style="font-size: 9pt; color: blue">XML</span><span style="font-size: 9pt; color: blue; font-family: 宋体">、事务控?/span></p> <p><span style="font-size: 9pt; color: blue">Micro Edition(</span><span style="font-size: 9pt; color: blue; font-family: 宋体">微羃?/span><span style="font-size: 9pt; color: blue">) J2ME </span><span style="font-size: 9pt; color: blue; font-family: 宋体">包含</span><span style="font-size: 9pt; color: blue">J2SE</span><span style="font-size: 9pt; color: blue; font-family: 宋体">中一部分c，用于消费cȝ子品的软g开发。比如：呼机、智能卡、手机?/span><span style="font-size: 9pt; color: blue">PDA</span><span style="font-size: 9pt; color: blue; font-family: 宋体">、机盒</span></p> <p><span style="font-size: 9pt; color: blue; font-family: 宋体">他们的范围是Q?/span><span style="font-size: 9pt; color: blue">J2SE</span><span style="font-size: 9pt; color: blue; font-family: 宋体">包含?/span><span style="font-size: 9pt; color: blue">J2EE</span><span style="font-size: 9pt; color: blue; font-family: 宋体">中，</span><span style="font-size: 9pt; color: blue">J2ME</span><span style="font-size: 9pt; color: blue; font-family: 宋体">包含?/span><span style="font-size: 9pt; color: blue">J2SE</span><span style="font-size: 9pt; color: blue; font-family: 宋体">的核心类Q但新添加了一些专有类?/span></p> <p><span style="font-size: 9pt; color: blue; font-family: 宋体">如果?/span><span style="font-size: 9pt; color: blue">c/s</span><span style="font-size: 9pt; color: blue; font-family: 宋体">架构的话Q?/span><span style="font-size: 9pt; color: blue">j2se</span><span style="font-size: 9pt; color: blue; font-family: 宋体">应该要精?/span></p> <p><span style="font-size: 9pt; color: blue; font-family: 宋体">如果?/span><span style="font-size: 9pt; color: blue">b/s</span><span style="font-size: 9pt; color: blue; font-family: 宋体">架构的话Q?/span><span style="font-size: 9pt; color: blue">j2ee</span><span style="font-size: 9pt; color: blue; font-family: 宋体">要熟悉?/span></p> <p><span style="font-size: 9pt; color: blue; font-family: 宋体">如果做手机的话，</span><span style="font-size: 9pt; color: blue">j2me</span><span style="font-size: 9pt; color: blue; font-family: 宋体">会是你的选择</span></p> <img src ="http://www.aygfsteel.com/jxhkwhy/aggbug/193888.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.aygfsteel.com/jxhkwhy/" target="_blank">UR?/a> 2008-04-17 23:29 <a href="http://www.aygfsteel.com/jxhkwhy/articles/193888.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>J2EE的体pȝ?/title><link>http://www.aygfsteel.com/jxhkwhy/articles/193886.html</link><dc:creator>UR?/dc:creator><author>UR?/author><pubDate>Thu, 17 Apr 2008 15:25:00 GMT</pubDate><guid>http://www.aygfsteel.com/jxhkwhy/articles/193886.html</guid><wfw:comment>http://www.aygfsteel.com/jxhkwhy/comments/193886.html</wfw:comment><comments>http://www.aygfsteel.com/jxhkwhy/articles/193886.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.aygfsteel.com/jxhkwhy/comments/commentRss/193886.html</wfw:commentRss><trackback:ping>http://www.aygfsteel.com/jxhkwhy/services/trackbacks/193886.html</trackback:ping><description><![CDATA[  <p><span style="font-size: 9pt; color: blue; font-family: 宋体">◆运行在客户端机器上的客户层lg</span><span style="font-size: 9pt; color: blue">(</span><span style="font-size: 9pt; color: blue; font-family: 宋体">应用客户端程序和</span><span style="font-size: 9pt; color: blue">Applets</span><span style="font-size: 9pt; color: blue; font-family: 宋体">是客户层lg</span><span style="font-size: 9pt; color: blue">) </span></p> <p><span style="font-size: 9pt; color: blue; font-family: 宋体">◆运行在</span><span style="font-size: 9pt; color: blue">J2EE</span><span style="font-size: 9pt; color: blue; font-family: 宋体">服务器上?/span><span style="font-size: 9pt; color: blue">Web</span><span style="font-size: 9pt; color: blue; font-family: 宋体">层组?/span><span style="font-size: 9pt; color: blue">(Java Servlet</span><span style="font-size: 9pt; color: blue; font-family: 宋体">?/span><span style="font-size: 9pt; color: blue">JavaServer Pages(JSP)</span><span style="font-size: 9pt; color: blue; font-family: 宋体">?/span><span style="font-size: 9pt; color: blue">web</span><span style="font-size: 9pt; color: blue; font-family: 宋体">层组?/span><span style="font-size: 9pt; color: blue">) </span></p> <p><span style="font-size: 9pt; color: blue; font-family: 宋体">◆运行在</span><span style="font-size: 9pt; color: blue">J2EE</span><span style="font-size: 9pt; color: blue; font-family: 宋体">服务器上的业务逻辑层组?/span><span style="font-size: 9pt; color: blue">(Enterprise JavaBeans(EJB)</span><span style="font-size: 9pt; color: blue; font-family: 宋体">是业务层lg</span><span style="font-size: 9pt; color: blue">) </span></p> <span style="font-size: 9pt; color: blue; font-family: 宋体">◆运行在</span><span style="font-size: 9pt; color: blue; font-family: 'Times New Roman'">EIS</span><span style="font-size: 9pt; color: blue; font-family: 宋体">服务器上的企业信息系l?/span><span style="font-size: 9pt; color: blue; font-family: 'Times New Roman'">(EntERPrise information system)</span><span style="font-size: 9pt; color: blue; font-family: 宋体">层Y?/span><span style="font-size: 9pt; color: blue; font-family: 'Times New Roman'">(</span><span style="font-size: 9pt; color: blue; font-family: 宋体">企业信息pȝ层处理企业信息系lY件包括企业基pȝ例如企业资源计划</span><span style="font-size: 9pt; color: blue; font-family: 'Times New Roman'"> (ERP) , </span><span style="font-size: 9pt; color: blue; font-family: 宋体">大型Z务处?/span><span style="font-size: 9pt; color: blue; font-family: 'Times New Roman'">, </span><span style="font-size: 9pt; color: blue; font-family: 宋体">数据库系l?/span><span style="font-size: 9pt; color: blue; font-family: 'Times New Roman'">,</span><span style="font-size: 9pt; color: blue; font-family: 宋体">和其它的遗留信息pȝ。例如，</span><span style="font-size: 9pt; color: blue; font-family: 'Times New Roman'">J2EE </span><span style="font-size: 9pt; color: blue; font-family: 宋体">应用lg可能Z数据库连接需要访问企业信息系l?/span><span style="font-size: 9pt; color: blue; font-family: 'Times New Roman'">)</span> <img src ="http://www.aygfsteel.com/jxhkwhy/aggbug/193886.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.aygfsteel.com/jxhkwhy/" target="_blank">UR?/a> 2008-04-17 23:25 <a href="http://www.aygfsteel.com/jxhkwhy/articles/193886.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>J2EE是什么？Z么要用J2EEQJ2EE到底是解决企业的什么问题？http://www.aygfsteel.com/jxhkwhy/articles/193885.htmlUR?/dc:creator>UR?/author>Thu, 17 Apr 2008 15:24:00 GMThttp://www.aygfsteel.com/jxhkwhy/articles/193885.htmlhttp://www.aygfsteel.com/jxhkwhy/comments/193885.htmlhttp://www.aygfsteel.com/jxhkwhy/articles/193885.html#Feedback0http://www.aygfsteel.com/jxhkwhy/comments/commentRss/193885.htmlhttp://www.aygfsteel.com/jxhkwhy/services/trackbacks/193885.html  J2EE是一U利?/span>Java 2q_来简化企业解x案的开发、部|和理相关复杂问题的体pȝ构，可以用于开发大型的、多层次的以及分布式的企业应用pȝ

从严格的意义上说Q?/span>J2EEq不是一U语a。它是一l规范、技术框架及技术的集合Q用于创建分布式企业pȝ?/span>J2EE׃些程序语a和脚本语al成Q包?/span>Java?/span>XML?/span>JSP?/span>HTML?/span>SQL{等?/span>J2EE的优ҎQ跨q_可移植性（cross-platform portabilityQ，开源代码库的可用性（availability of open-source librariesQ，服务端的大容量调度基敎ͼa huge server-side deployment baseQ、符合大多数W3C标准{?/span>

J2EEq_的优?/span>

摘要: J2EEq_支持化的、基于组件开发模型，׃J2EEZJava~程语言?/span>J2SEq_

1.化结?/span>

J2EEq_支持化的、基于组件开发模型，׃J2EEZJava~程语言?/span>J2SEq_Q它提供了编写一ơ，随处q行的可UL性，遵@J2EE标准的所有服务器都支持该模型?/span>

EJBlg使编写应用程序更为简单。尽?/span>EJB体系l构复杂Q但应用E序开发h员一般都必再~写讉Kpȝ服务的代码，EJB容器会实现系l的服务，例如Q事务、安全性等?/span>

另外Q?/span>J2EEq支持异构环境。基?/span>J2EE的应用程序不依赖M特定操作pȝ、中间g或硬Ӟ因此Q设计合理的ZJ2EE的程序只需开发一ơ就可以部v到各U^収ͼq在典型的异构企业算环境中是十分关键的?/span>J2EE标准q允许客戯购与J2EE兼容的第三方的现成组Ӟ把其部v到异构环境中Q节省了p己制订整个方案所需的费用?/span>

2.提高开发效?/span>

׃lg技术的使用Q可以按照开发h员的技能对应用E序开发进行分工，q行开发，提供整体开发效率。例如：囑Ş设计师创?/span>JSP模板Q商业逻辑p领域的专家完成，JSP面?/span>EJB?/span>Java工程师完成，应用E序的装配和部v由团队中其他的成员完成，其中许多工作可以同时q行Q有助于加速应用程序的开发?/span>

3.可移植性强

除了Java语言固有的可UL性外Q?/span>EJB体系l构?/span>Bean和支持该Bean的容器之间提供了一套标准化的应用程序编E接口，q开发h员能够将Bean从一U操作环境移植到另一U操作环境，而无需重新~写其源代码?/span>

4.重用性好

׃?/span>EJB模型中，各个软glg都是严格分离的，因此Q可以从现有的Y件组件装配出服务器端应用E序Q这与从现有?/span>JavaBean可以装配出客L应用E序一P使Y件能够重用?/span>

5.易于l护

Zlg的设计简化了应用E序的维护。由于组件可以被独立地更新和替代Q通过更新应用E序中特定的lgQ新的功能可以被很容易地增加?/span>

6.可׾~?/span>

企业必须要选择一U服务器端^収ͼ以便满那些在它们系l上q行商业动作大批新客戗基?/span>J2EEq_的应用程序可被部|到各种操作pȝ上，例如Q可被部|到高端UNIX或其他的大型机系l上?/span>J2EE领域的供应商提供了更为广泛的负蝲q{略Q能消除pȝ中的瓉Q允许多台服务器集成部vQ实现可高度伸羃的系l，满未来商业应用的需要?/span>

7.被广泛接?/span>

主要?/span>IT供应用商都采U?/span>EJB体系l构Q不同供应商的品只要符?/span>EJB体系l构Q就都是可互操作的?/span>

8.保护投资

׃企业必须适应新的商业需求，充分利用现有的企业信息系l投资，而不是重新制定，全盘更新Ҏ变得尤为重要，q样Q一个以渐进的（而不是激q的Q全盘否定的Q方式徏立在现有pȝ?span>上的服务器^台是大多数公司所希望的?/span>

J2EE架构可以充分利用用户有的投资Q通过允许现有的信息pȝ和资?/span>“包裹”?/span>J2EE应用E序中，不要求客h换现有技术。事实上Q在关系数据库中存储数据的企业，已经有了一套已具雏形的实体BeanQ正{着通过EJB外壳去访问?/span>

q之所以成为可能，主要是因?/span>J2EE?/span>有广泛的业界支持和一些重要的“企业计算”领域供应商的参与Q每一个供应商都对现有的客h供了不用废弃自己已有投资的升U途径。由于基?/span>J2EEq_的品几乎能够在M操作pȝ和硬件运行，现有的操作系l和g也能被保留用?/span>

一、J2EE提出的背?/span>
1?企业U应用框架的需?
在许多企业应用中，例如数据库连接、邮件服务、事务处理等都是一些通用企业需求模块，q些模块如果每次再开发中都由开发h员来完成的话Q将会造成开发周期长和代码可靠性差{问题。于是许多大公司开发了自己的通用模块服务。这些服务性的软gpd同陈Z间g?
2?Z通用必须要提范，不然无法辑ֈ通用
在上面的需求基之上Q许多公叔R开发了自己的中间gQ但其与用户的沟通都各有不同Q从而导致用h法将各个公司不同的中间gl装在一块ؓ自己服务。从而生瓶颈。于是提出标准的概念。其实J2EE是ZJAVA技术的一pd标准?
注：中间件的解释 中间件处在操作系l和更高一U应用程序之间。他充当的功能是Q将应用E序q行环境与操作系l隔，从而实现应用程序开发者不必ؓ更多pȝ问题忧虑Q而直接关注该应用E序在解决问题上的能??/span>



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