什么是富客户端互联网应用程序
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">原稿</span><span lang="EN-US">:Rich Internet Applications with Adobe Flex & Java 28-30</span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">章节</span><span lang="EN-US">:Architecture of Rich Internet Applications</span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">作者</span><span lang="EN-US">:Yakov Fain,Dr.Vector Rasputnis,Anatole Tartakovsky</span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">时间</span><span lang="EN-US">:<st1:chsdate w:st="on" isrocdate="False" islunardate="False" day="27" month="4" year="2008">2008-4-27</st1:chsdate></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">翻译者</span><span lang="EN-US">:</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">刘锦行</span><span lang="EN-US">(whizen)</span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">修订</span><span lang="EN-US">:</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">什么是富客户端互联网应用程序</span><span lang="EN-US">?</span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">在软件工业的历史已经发生了惊人的改变</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">我们从单机时代进入了客户端</span><span lang="EN-US">/</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">服务器端的时代</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">曾经为客户带来便利和生产力提升的单机系统进入了历史</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">随着互联网时代的到来</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">一群梦想家正在改变我们的桌面</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">计算机销售商和</span><span lang="EN-US">IT</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">公司渴望从复杂的客户端</span><span lang="EN-US">/</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">服务器端的版本管理中解脱出来</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">而技术人员却需要他们来进行复杂的多层计算</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这个时候</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">客户端</span><span lang="EN-US">/</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">服务器端模式成为了负担</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">为了以示区别</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这种虽然很不错但是显得很传统的桌面应用程序被称为</span><span lang="EN-US">”</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">富客户端</span><span lang="EN-US">”.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">另外</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">那些多线程</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">传递消息</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">持久甚至简单的玩具都在服务器上运算的</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">如果我们不去想这些</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">只知道最后他为用户提供了丰富的体验而且甚至完全不用去部署</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这个让我们感觉良好的家伙是新的应用程序类型称之为</span><span lang="EN-US">:</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">瘦客户端</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">然后我们遇到了新的挑战</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">那就是我们进入了富客户端互联网应用程序的年代</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这是一种使用颇具怀旧色彩的强力桌面应用程序来代替那些可恶的需要下载的页面</span><span lang="EN-US">.RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">们运行在虚拟机之上</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">具备马上成为一个全功能桌面程序的潜力</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">与那些只需要从服务器上下载而来只能显示简单内容的</span><span lang="EN-US">WEB</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">页面不同的是</span><span lang="EN-US">,RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">却是的的确确运行在客户端的</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">就像在客户端</span><span lang="EN-US">/</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">服务器端那个年代一样</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">能够在本地的处理很多的数据</span><span lang="EN-US">(</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">例如</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">排序</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">分组</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">过滤</span><span lang="EN-US">),</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">相关的分析师认为在未来的</span><span lang="EN-US">3,4</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">年内将有很多新开发的项目使用</span><span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">技术</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">一个</span><span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">结合了使用</span><span lang="EN-US">WEB</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">带来的低成本的部署方案和丰富的用户体验的好处</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">最少比现在的桌面应用程序要好</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">而且</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">因为</span><span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">不需要刷新整个页面来更新其中的数据</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">所以响应速度也更快而且通讯消耗也更低</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">有点类似一个部署了整个地球的客户端</span><span lang="EN-US">/</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">服务器端应用程序</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">让我们来描述一个购物车的例子</span><span lang="EN-US">,”</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">过时</span><span lang="EN-US">”</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">的</span><span lang="EN-US">WEB</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">页面和</span><span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">之间的区别</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">不使用</span><span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">技术的</span><span lang="EN-US">WEB</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">应用程序是基于页面的</span><span lang="EN-US">. HTTP</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">协议是个无状态的协议</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">所以当用户从一个页面移动到另外一个页面的时候</span><span lang="EN-US">,WEB</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">浏览器无法记得用户在上个页面做的操作</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">为了治疗这个</span><span lang="EN-US">”</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">失忆症</span><span lang="EN-US">”,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">必须使用</span><span lang="EN-US">HTTP session</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">来在服务器端记录用户的状态</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">假设以下是在线购物线程的流程</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">依次进行以下操作</span><span lang="EN-US">:</span>
<span lang="EN-US">1,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">用户在</span> <span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">页面</span><span lang="EN-US">#1 </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">搜索一个商品</span>
<span lang="EN-US">2,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">服务器会处理这个请求</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">并且返回一个可能包含</span><span lang="EN-US">(</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">也可能不包含</span><span lang="EN-US">)</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">符合要求商品的页面</span><span lang="EN-US">#2</span>
<span lang="EN-US">3,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">用户将这个物品放入购物车</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这个操作也会导致在服务器端也要创造出购物车并且储存用户的商品</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">随后</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">服务器将返回一个页面</span><span lang="EN-US">#3,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这样用户就能够继续购物</span><span lang="EN-US">(</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">重复</span><span lang="EN-US">2 3</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">步</span><span lang="EN-US">)</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">或者去结帐</span><span lang="EN-US">#4</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">在结帐操作中</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">服务器会从</span><span lang="EN-US">session</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">对象中检索被选择的商品</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">并且返回一个页面</span><span lang="EN-US">#5</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">来告诉用户填写物流信息</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这些数据返回到服务器进行保存后</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">再次返回一个页面</span><span lang="EN-US">#6</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">给客户端</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">里面包含着支付的相关信息</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">随后将在页面</span><span lang="EN-US">#7</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">中确认支付信息并且最终完成购物</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这个最简单的在线购物流程却要与服务器之间交互</span><span lang="EN-US">7</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">个来回</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这与桌面应用程序有相当大的区别</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">虽然在</span><span lang="EN-US">WEB</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">应用程序之中</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">虽然刷新单个的页面很快</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">而且通常用户都能接受</span><span lang="EN-US">8</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">秒以内的延迟</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">但是这样能够刺激用户来完成购物呢</span><span lang="EN-US">?</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">在想一下</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">因为每次你的系统给了用户</span><span lang="EN-US">7</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">次的重新考虑的机会</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">假设网络和服务器很慢的时候结果又是如何呢</span><span lang="EN-US">?</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">漫长的等待只可能让你的潜在客户离开你的店铺</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">对比起瘦客户端来说</span><span lang="EN-US">, RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">程序去除了这些繁杂的应答来回</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">而且因为大多数处理都是在客户端上执行的</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这样而来极大的改善了系统在大量数据处理的时候的性能</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">另外</span><span lang="EN-US">,RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">程序是可以持有状态的</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">他能在客户端储存数据</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">简单的说</span><span lang="EN-US">,RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">不是一些完全靠服务器端控制的页面</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">他们是确确实实在客户端上运行的程序</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">只在处理和交互数据的时候和服务器端进行通讯</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">程序可谓同时具备用户友好的界面和企业级应用程序的优点</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">众所周知在用户最后结帐的时候页面却失去了回应而导致不得不取消掉订单这样的事故让一些电子商务网站如在线票务预订系统或者在线零售商蒙受损失</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">我们有相当多的用户投诉电话</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">为客服中心和系统本身都产生了不可忽视的成本增长</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">需要相当之多的雇员来维持系统的运行不得不说对于一个企业的生产力造成了影响</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">而</span><span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">能够提供比</span><span lang="EN-US">HTML</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">应用程序更好的效率</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">这将减少操作和构造的成本</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">最后</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">我们来介绍一下一些设计优良的</span><span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">用来构造我们的</span><span lang="EN-US">”</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">捕鼠器</span><span lang="EN-US">”(</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">指用来引诱用户上钩</span><span lang="EN-US">)</span>
<span lang="EN-US"><o:p> </o:p></span>
<span lang="EN-US">2002</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">年的时候</span><span lang="EN-US">,MACROMEDIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">公司展示了富客户端应用程序的模型</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">它让所有的</span><span lang="EN-US">”</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">老旧</span><span lang="EN-US">”</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">的</span><span lang="EN-US">WEB 1.0</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">页面颤抖</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">但是最早的</span><span lang="EN-US">RIA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">应用程序却是在</span><span lang="EN-US">1995</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">年由</span><span lang="EN-US">JAVA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">创造出来的</span><span lang="EN-US">.JAVA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">最初被大家接受的是一个叫做</span><span lang="EN-US">applets</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">的一个可以下载的小程序</span><span lang="EN-US">.applets</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">是使用</span><span lang="EN-US">java AWT(</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">之后是</span><span lang="EN-US">Swing)</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">类库做成的</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">依靠浏览器上的</span><span lang="EN-US">JVM</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">运行</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">但是因为相当使用起来相当有技术难度</span><span lang="EN-US">,applets</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">最终并没有怎么流行</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">反倒是</span><span lang="EN-US">JAVA</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">自身在服务器端和移动平台上风光无限</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span lang="EN-US">2004</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">年的时候</span><span lang="EN-US">,TIM O’REILLY</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">引用了一个新词汇</span><span lang="EN-US"> WEB 2.0.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">但是</span><span lang="EN-US">WEB 2.0</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">的标准却从来没有被清晰的定义过</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">对于有些人来说</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">一些看起来很</span><span lang="EN-US">COOL</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">的网站就可以被称为</span><span lang="EN-US">WEB 2.0.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">将这些看起来很</span><span lang="EN-US">COOL</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">的网站贴上</span><span lang="EN-US">WEB 2.0</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">的标志似乎很流行</span><span lang="EN-US">.</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">但是通常</span><span lang="EN-US">WEB 2.0</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">是指一些面向公众的网站</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">人们可以相互的合作和交流并且在这些网站上面建立关于他们自身的页面</span><span lang="EN-US">.WIKI</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">百科上有一片相当长的文章</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">或许能够为你明白这个词汇的真实意义给予一些帮助</span><span lang="EN-US">.</span>
<span lang="EN-US"><o:p> </o:p></span>
<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">如今甚至出现了</span><span lang="EN-US">WEB 3.0,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">指那些</span><span lang="EN-US">semantic(</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">不明</span><span lang="EN-US">)</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">页面</span><span lang="EN-US">……</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">好吧让我们停止玩名字的游戏</span><span lang="EN-US">,</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''Times New Roman''; mso-hansi-font-family: ''Times New Roman''">回到本书的主题上来</span><span lang="EN-US">:RIA.</span>
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