200603061723295.html

软件工程的红包书

<P>1. 白盒与黑盒框架 </P>
<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 框架可分为白盒(White-Box)与黑盒(Black-Box)两种框架。 </P>
<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;基于继承的框架被称为白盒框架。所谓白盒即具备可视性，被继承的父类的内部实现细节对子类而言都是可知的。利用白盒框架的应用开发者通过衍生子类或重写父类的成员方法来开发系统。子类的实现很大程度上依赖于父类的实现，这种依赖性限制了重用的灵活性和完全性。但解决这种局限性的方法可以是只继承抽象父类，因为抽象类基本上不提供具体的实现。白盒框架是一个程序骨架，而用户衍生出的子类是这个骨架上的附属品。 </P>
<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 基于对象构件组装的框架就是黑盒框架。应用开发者通过整理、组装对象来获得系统的实现。用户只须了解构件的外部接口，无须了解内部的具体实现。另外，组装比继承更为灵活，它能动态地改变，继承只是一个静态编译时的概念。 </P>
<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 在理想情况下，任何所需的功能都可通过组装已有的构件得到，事实上可获得的构件远远不能满足需求，有时通过继承获得新的构件比利用已有构件组装新构件更容易，因此白盒和黑盒将同时应用于系统的开发中。不过白盒框架趋向于向黑盒框架发展，黑盒框架也是系统开发希望达到的理想目标。 </P>
<P>2. 热点、食谱以及好莱坞原则 </P>
<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;成功的框架开发需要确定领域专用的“热点” (Hot spot)。应用开发者在框架的基础上进行开发，只须扩展框架的某些部分，“热点”就是在应用领域的一种扩展槽，开发者根据自己的需要填充这些扩展槽。“热点”使框架具有灵活性，如在具体的实现中，扩展槽可以被看成是一些抽象类，开发者通过重写抽象方法获得具体实现。 </P>
<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; “食谱” (Cookbook)就是描述如何使用框架方法的文档。在“食谱”中包含了许多“烹饪”方法，这些“烹饪”方法相当于一些具体的操作步骤，描述了为解决某一专门问题如何使用框架的详细方法。框架的内部设计和实现细节通常不出现在“食谱”中。 </P>
<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 框架的一个重要特征就是用户定义的方法经常被框架自身调用，而不是从用户的应用代码中调用。这种机制常称为“好莱坞原则”(Hollywood Principle)或“别调用我们，我们会调用您”。<BR></FONT></P>
<P><FONT face=Verdana><STRONG>五、常见的JAVA框架有什么？</STRONG></FONT></P>
<P><FONT face=Verdana><STRONG>WAF：</STRONG><BR>全称：WEB APPLICATION FRAMEWORK<BR>主要应用方面：<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200604241156485.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200604241156485.html'" tppabs="http://www.itisedu.com/phrase/200604241156485.html" target="_new">EJB</a>层，（WEB层也有，但是比较弱）。<BR>主要应用技术：EJB等<BR>出处：java.sun.com/blueprints/code/index.html"&gt;http://java.sun.com/blueprints/code/index.html<BR>简述：这是SUN在展示J2EE平台时所用的例子PetStore(宠物商店系统)里面的框架。是SUN蓝皮书例子程序中提出的应用框架。它实现了 MVC和其他良好的<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200603061631585.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200603061631585.html'" tppabs="http://www.itisedu.com/phrase/200603061631585.html" target="_new">设计模式</a>。SUN的网站上有技术资料，最好下载PetStore来研究，WEBLOGIC里自带此系统，源码在bea\weblogic700\samples\server\src\petstore。这是学习了解J2EE的首选框架。<BR>免费。</FONT></P>
<P><FONT face=Verdana><STRONG><a href="javascript:if(confirm('http://www.itisedu.com/phrase/200605110915235.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200605110915235.html'" tppabs="http://www.itisedu.com/phrase/200605110915235.html" target="_new">Struts</a>:</STRONG><BR>主要应用方面：WEB层。<BR>主要应用技术：JSP,TagLib,<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200604251741535.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200604251741535.html'" tppabs="http://www.itisedu.com/phrase/200604251741535.html" target="_new">JavaBean</a>,<a href="200604231236585.html" tppabs="http://www.itisedu.com/phrase/200604231236585.html" target="_new">XML</a>等<BR>出处：http://jakarta.apache.org/struts/index.html<BR>简述：这是APACHE的<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200603091812115.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200603091812115.html'" tppabs="http://www.itisedu.com/phrase/200603091812115.html" target="_new">开源</a>项目，目前应用很广泛。基于<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200604231324325.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200604231324325.html'" tppabs="http://www.itisedu.com/phrase/200604231324325.html" target="_new">MVC模式</a>，结构很好，基于JSP。Jbuilder8里已经集成了STRUTS1.02的制作。<BR>免费。</FONT></P>
<P><FONT face=Verdana>简述WAF+STRUTS结合的例子：WEB层用STRUTS，EJB层用WAF：<BR>JSP(TagLib)——&gt;ActionForm——&gt;Action&nbsp; ——&gt;<BR>&nbsp; Event——&gt;EJBAction——&gt;EJB&nbsp;&nbsp;&nbsp; ——&gt;<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200604162200335.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200604162200335.html'" tppabs="http://www.itisedu.com/phrase/200604162200335.html" target="_new">DAO</a>——&gt;<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200604231244235.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200604231244235.html'" tppabs="http://www.itisedu.com/phrase/200604231244235.html" target="_new">Database</a>&nbsp; <BR>JSP（TagLib） (forward) &lt;——Action&nbsp; &lt;——EventResponse&lt;——&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </FONT></P>
<P><FONT face=Verdana><STRONG><a href="javascript:if(confirm('http://www.itisedu.com/phrase/200607121707255.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200607121707255.html'" tppabs="http://www.itisedu.com/phrase/200607121707255.html" target="_new">Turbine</a>：</STRONG><BR>主要应用方面：WEB层。<BR>主要应用技术：<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200603091005185.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200603091005185.html'" tppabs="http://www.itisedu.com/phrase/200603091005185.html" target="_new">servlet</a>等<BR>出处：http://jakarta.apache.org/turbine/index.html<BR>简述：这是APACHE的开源项目。基于SERVLET。据说速度比较快，基于service（pluggable implementation可插拔的执行组件）的方式提供各种服务。<BR>免费。</FONT></P>
<P><FONT face=Verdana><STRONG><a href="javascript:if(confirm('http://www.itisedu.com/phrase/200607121801235.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200607121801235.html'" tppabs="http://www.itisedu.com/phrase/200607121801235.html" target="_new">COCOON</a>：</STRONG><BR>主要应用方面：WEB层。<BR>主要应用技术：XML，XSP，servlet等<BR>出处：http://cocoon.apache.org/2.0/<BR>简述：这是APACHE的一个开源项目。基于XML，基于XSP（通俗地说，XSP是在XML静态文档中加入Java程序段后形成的动态XML文档。）。特点是可以与多种数据源交互，包括<a href="200602282323195.html" tppabs="http://www.itisedu.com/phrase/200602282323195.html" target="_new">文件</a>系统，<a href="200602271218062.html" tppabs="http://www.itisedu.com/phrase/200602271218062.html" target="_new">数据库</a>，LDAP，XML资源库，网络数据源等。<BR>免费。</FONT></P>
<P><FONT face=Verdana><STRONG>ECHO：</STRONG><BR>主要应用方面：WEB层。<BR>主要应用技术：servlet等<BR>出处：http://www.nextapp.com/products/echo/<BR>简述：nextapp公司的一个开源项目。基于SERVLET。页面可以做的很漂亮，结合echopoint，可以作出很多图形效果（里面用了jfreechart包）。使用<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200604251600225.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200604251600225.html'" tppabs="http://www.itisedu.com/phrase/200604251600225.html" target="_new">SWING</a>的思想来作网页，把HTML当作JAVA的类来做。但是大量使用Session，页面分帧（Frame）很多,系统资源消耗很大。<BR>免费。</FONT></P>
<P><FONT face=Verdana><STRONG>JATO：</STRONG><BR>全称：SUN ONE Application Framework<BR>主要应用方面：WEB层。<BR>主要应用技术：JSP,TagLib,JavaBean等<BR>出处：http://www.sun.com/<BR>简述：这是SUN推出的一个商业性框架，一看名字就知道是结合SUN ONE的平台推出的。我下载了JATO2.0看了一下，感觉有些简单，使用了JSP＋TagLib+JavaBean。如他的DOC所说JATO是适合用在小的WEB应用里。<BR>免费。</FONT></P>
<P><FONT face=Verdana><STRONG>TCF：</STRONG><BR>全称：Thin-<a href="javascript:if(confirm('http://www.itisedu.com/phrase/200604231337375.html  \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon.  \n\nDo you want to open it from the server?'))window.location='http://www.itisedu.com/phrase/200604231337375.html'" tppabs="http://www.itisedu.com/phrase/200604231337375.html" target="_new">Client</a> Framework<BR>主要应用方面：JAVA GUI。<BR>主要应用技术：JAVA application等<BR>出处：http://www.alphaworks.ibm.com/tech/tcf<BR>简述：这是IBM出的一个框架。基于MVC模式，基于JAVA Application。推荐一篇介绍文章：java/j-tcf1/index.shtml"&gt;http://www-900.ibm.com/developerWorks/cn/java/j-tcf1/index.shtml<BR>收费：每个企业对象license:2000美元。 </FONT></P>
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