敏捷软件开发读书笔记２——面向对象的设计原则

<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">SRP<span style=""> </span></span></span><span style="">单一职责原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">就一个类而言，应该仅有一个引起它变化的原因。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">OCP<span style=""> </span></span></span><span style="">开放封闭原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">软件实体（类、模块、函数等）应该对扩展是开放的（易于扩展），但是对于修改是封闭的（不应修改）。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">LSP<span style=""> </span>Liskov</span></span><span style="">替换原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">子类必须能够替换掉它们的基类。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">DIP<span style=""> </span></span></span><span style="">依赖倒置原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">抽象不应该依赖于细节，而细节应该依赖于抽象。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">ISP<span style=""> </span></span></span><span style="">接口隔离原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">不应该强迫用户依赖于他们不用的方法。接口属于用户，不属于它所在的类层次结构。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">REP<span style=""> </span></span></span><span style="">重用发布等价原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">重用的粒度就是发布的粒度。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">CCP<span style=""> </span></span></span><span style="">共同封闭原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">包中所有类对于同一类性质的变化应该是共同封闭的。一个变化若对一个包产生影响，则将对该包中的所有类产生影响，而对于其他的包不造成任何影响。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">CRP<span style=""> </span></span></span><span style="">共同重用原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">一个包中所有类应该是共同重用的。如果重用了包中的一个类，那么就要重用包中的所有类。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">ADP<span style=""> </span></span></span><span style="">无环依赖原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">在包的依赖关系图中，不允许存在环。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">SDP<span style=""> </span></span></span><span style="">稳定依赖原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">朝着稳定的方向进行依赖。</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style="font-family: Calibri;">SAP<span style=""> </span></span></span><span style="">稳定抽象原则</span></span></p>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"><span style="font-size: small;"><span lang="EN-US"><span style=""><span style="font-family: Calibri;"> </span></span></span><span style="">包的抽象程度应该和其稳定程度一致。</span></span></p>