�??xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/"><channel><title>&#35270;&#39057;&#19968;&#21306;&#22312;&#32447;&#25773;&#25918;&#44;&#20234;&#20154;&#32593;&#22312;&#32447;&#20813;&#36153;&#35266;&#30475;&#44;&#22235;&#23395;&#97;&#118;&#22312;&#32447;&#19968;&#21306;&#20108;&#21306;&#19977;&#21306;</title><link>http://www.aygfsteel.com/liuyf8688/category/54098.html</link><description /><language>zh-cn</language><lastBuildDate>Mon, 06 Jan 2014 06:32:42 GMT</lastBuildDate><pubDate>Mon, 06 Jan 2014 06:32:42 GMT</pubDate><ttl>60</ttl><item><title>谦卑的架构师</title><link>http://www.aygfsteel.com/liuyf8688/articles/408543.html</link><dc:creator>风沙</dc:creator><author>风沙</author><pubDate>Mon, 06 Jan 2014 01:17:00 GMT</pubDate><guid>http://www.aygfsteel.com/liuyf8688/articles/408543.html</guid><wfw:comment>http://www.aygfsteel.com/liuyf8688/comments/408543.html</wfw:comment><comments>http://www.aygfsteel.com/liuyf8688/articles/408543.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.aygfsteel.com/liuyf8688/comments/commentRss/408543.html</wfw:commentRss><trackback:ping>http://www.aygfsteel.com/liuyf8688/services/trackbacks/408543.html</trackback:ping><description><![CDATA[<div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">原文地址�Q�http://architects.dzone.com/articles/humble-architects</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"></div><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">谦卑对于软�g架构师来说不是一个很常见的特征。在参与�q�一些让人敬畏的架构后，�q�且最�q�还参与�q�一个��o人愉快的��目�Q�我以每个架构师都比较喜�Ƣ的方式�ȝ��了一些经验：作�ؓ一套规则�?/span><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">规则0�Q�不要装�p�涂�Q�Don't assume stupidity�Q?/strong></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">���像一些架构师假定开发�h���d��他们自己的设备，表现的将像个猴子。在我的�l�验里，�q�是很少会发生的。我只看到过一�U�开发�h员做事时犯糊涂的情况�Q�就是默默的抗议和反�Ҏ��构师。如果你认可�q�个规则�Q�接下就是一些细节�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">规则1�Q�你可能是错的（You may be wrong�Q?/strong></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">当审阅一些�h的设计理忉|���Q�我更喜�Ƣ开诚布公的���试问一些问题。我认�ؓ开发�h员可能忽略了一个关键点�Q�如�q�发。这儿有一些应对这些场景的�Ҏ���Q?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">1. 架构师：&#8220;你不能那样做�Q�因��Z��可能破坏代码设计准则�?#8221;</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">2. 架构师：&#8220;你不能那样做�Q�因为在多用��h��况下�Q�他是不安全的�?#8221;</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">3. 架构师：&#8220;你是否想�q�多用户�Ӟ��他如何工作呢�Q?#8221;</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">4. 架构师：&#8220;你的�Ҏ��如何应付多用户场景呢�Q?#8221;</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">亲爱的架构师�Q�请从最不可能到最有可能得��C��个尽可能好的�pȝ��的角度来评估�q�些�Ҏ��。（提示�Q�尽���有许多架构面对�q�个问题�l�常��p�|�Q�但�q�真的是一个项很容易的工作。）</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">规则2�Q��}慎选用技术（Be careful with technology�Q?/strong></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">每种技术都会带来成本。大部分技术只能带来很���的益处�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">�q�儿有一个我所�l�历�q�的成本大于益处的技术列表，因此���永不再使用�Q�如果你不知道他们，也不用担心。关键是数量。）�Q�JavaServer Pages, Java Server Faces, JAX-WS, Hibernate, Spring, EJB, Oracle SOA Server, IBM WebSphere, Wicket, Google Web Toolkit, Adobe Flex, JBoss jBPM, JMS�Q�all implementations�Q? JBoss�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">�q�儿有一个我比较愿意使用的技术列表：JUnit, Jetty, Joda-time, Java Standard Edition�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">�q�儿有一个你可能惌������试或模仿的谦虚的交���方式：</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">架构师：</strong><span style="font-size: 10pt;">你应该��用X技术�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">我：</strong><span style="font-size: 10pt;">我注意过X技术，我不认�ؓ他能帮助我解决业务问题�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">架构师：</strong><span style="font-size: 10pt;">你想表达的意思是什么呢�Q?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">我：</strong><span style="font-size: 10pt;">哦，我需要做�Q?..�Q�这些是X技术假讄����Q?..�Q�我不认��Z��们匹配得上�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">架构师：</strong><span style="font-size: 10pt;">那么你徏议��用什么来替代他呢�Q?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">我：</strong><span style="font-size: 10pt;">�?..�Q�我认�ؓ我们可以使用普通的Java来解军_��。事实上�Q�我昨晚做了一个非常好的demo来证明其可行性（I made a pretty good proof-of-concept yesterday evening.�Q��?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">受�h���敬的架构师�Q�很��P��让我们用它吧�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">规则3�Q�一致性不像你认�ؓ的那样重要（Consistency isn't as important as you think�Q?/strong></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">如果我有一便士�Q�每�ơ我都将会听�?..</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">架构师：</strong><span style="font-size: 10pt;">&#8220;是的�Q�我觉得�q�种方式可能比较�W�，但你必须�q�样做。你是知道的�Q�如果不�q�样做，�pȝ��会��生不一致�ƈ且是不可�l�护�?#8221;</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">相当然吧�Q�我不常常做�l�护工作�Q�但是我处理��M���pȝ���Ӟ��最困难的部分通常是理解系�l�的业务逻辑。X�pȝ���Q�有一套业务逻辑�Q�还是Y�pȝ���Q�另一套业务逻辑�Q�是不是一致性的问题在让我失眠的��d��列表中优先��都是被排的比较低的�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">事实上，X�pȝ��是非常复杂的�Q�因��Z��有十二层且每层都要和Y�pȝ��一致。现在这让我特别生气。不同的上下文环境有不同的权衡�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">哦，是的�Q�还记得规则0吗？假如在一个给定的环境中，开发�h员尝试�ؓ�q�个环境创造一个好的解��x��案�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">哦，是的�Q�另一件事�Q�我从未见到�q�一个小的可�l�护的东西复杂到难以理解。复杂只是因为我们让他发展壮大造成的�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">哦，好的�Q�还有另外一件事�Q�如果因为开发�h员中一些��用这��L��花括��h��式，另外一部分使用另一�U�花括号方式�~�程�Q�而导致开发�h员大�늝��q�离�~�码。我���失��L��有对人性的信�Ԓ�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">规则4�Q�自底向上的一致性不如从上到下的一��_��Bottom-up consistency beats top-down consistency�Q?/strong></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">�q�儿有一�U�我有能力创建系�l�内部一致性的�Ҏ���Q?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">1. 使用更容易被沿用�Q�而不是��用具有突破性的架构来创��Z��个参考应用。如果你�q�样做的话，在遇��C��些偏���L��构的��x���Ӟ��除非他们真的需要，在这�U�情况下他是非常好的�Q�否则开发�h员将会摇头�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">2. 培训一�U�交叉交���的文化�Q�Foster a culture of cross-pollination�Q�：彼此互相看代码的开发�h员一致性要比仅仅看他自�׃��码的开发�h员更好。结对编�E�（Pair programming�Q�，代码review�Q�Code reviews�Q�和培训交叉技术分享会�Q�Tech sharing sessions all foster cross-pollination�Q��?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">规则5�Q�跨�pȝ��的策略重用不是最优选择�Q�Tactical reuse in across systems is suboptimization�Q?/strong></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">重用���会产生耦合。如果系�l�X和系�l�Y重用了一些功能，�pȝ��X需要对功能�q�行修改�Q�这���会影响到系�l�Y。但臛_���Q�工作在�pȝ��X的团队必���d��定对重用的功能做一份私有副本。那意味着他不再被真正的重用。在极端情况下，�׃��寚w��用功能的修改�Q�将造成�pȝ��Y产生bug�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">当你跨系�l�重用时�Q�那应该是稳定的�Q�例如，Java SE�q�_��或别的东西，如此�E�_���Q�你不需要自己动手做它）或策略性的内容。关于策略重用，是指整合信息但不是仅仅复制功能的服务�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">换句话说�Q�重用应该是要不被��用，要不被集成。副本是你的朋友�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">规则6�Q�分辨规则和教条�Q�Separate between rules and dogma�Q?/strong></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">有三�U�原因��用这个�Q何编码规范中都有的规则：</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">1. 不安全（Unsafe�Q�：代码在某�U�场景（真实存在�Q�非理论上）中会出现bug</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">2. 令�h费解�Q�Incomprehensible�Q�：&#8220;�?#8221;不理解这是怎么回事</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">3. 旁门左道 �Q�Heresy�Q�：使用了大安���不喜�Ƣ的方式来写代码</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">抽查���试�Q�是否你有这样一个规则，&#8220;所有属性必���L��注释&#8221;。关于安全问题，关于易理解问题或是旁门左道？使用�q�个例子做�ؓ标准�Q?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><div style="background-color:#eeeeee;font-size:13px;border:1px solid #CCCCCC;padding-right: 5px;padding-bottom: 4px;padding-left: 4px;padding-top: 4px;width: 98%;word-break:break-all"><!--<br /><br />Code highlighting produced by Actipro CodeHighlighter (freeware)<br />http://www.CodeHighlighter.com/<br /><br />--><span style="color: #008000; ">/**</span><span style="color: #008000; "><br />&nbsp;*&nbsp;Contains&nbsp;the&nbsp;name&nbsp;value&nbsp;of&nbsp;the&nbsp;object<br />&nbsp;</span><span style="color: #008000; ">*/</span><br /><span style="color: #0000FF; ">private</span>&nbsp;String&nbsp;name;</div></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">关于&#8220;在左花括号前面没有换�?#8221;规则�Q�关�?#8220;花括��h��式应该统一&#8221;的规则？是否�W�合不安全代码，不易理解或旁门左道？</span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">我们应该更关注在特定场景下写适当的代码，���关注一致性�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><strong style="font-size: 10pt;">最后：谦卑�Q�Be humble�Q?/strong></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">在我从事软�g开发的那些�q�里�Q�我见过到��Y件架构师的伤完���多于帮助。做��Z��个职业角�Ԍ��如果我们解雇他们�Q�我们自己）�Q�我们将节省很多钱。那怕我们仍付给他们薪水�?/span></div><div style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;"><span style="font-size: 10pt;">如果你工作在一个他们造成的伤完���多于他们所能阻止，你有两个选项�Q�你可以���试改善或在没有人的时候祈�����?/span></div></div><img src ="http://www.aygfsteel.com/liuyf8688/aggbug/408543.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.aygfsteel.com/liuyf8688/" target="_blank">风沙</a> 2014-01-06 09:17 <a href="http://www.aygfsteel.com/liuyf8688/articles/408543.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>面向对象六原�?/title><link>http://www.aygfsteel.com/liuyf8688/articles/408469.html</link><dc:creator>风沙</dc:creator><author>风沙</author><pubDate>Sat, 04 Jan 2014 01:19:00 GMT</pubDate><guid>http://www.aygfsteel.com/liuyf8688/articles/408469.html</guid><wfw:comment>http://www.aygfsteel.com/liuyf8688/comments/408469.html</wfw:comment><comments>http://www.aygfsteel.com/liuyf8688/articles/408469.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.aygfsteel.com/liuyf8688/comments/commentRss/408469.html</wfw:commentRss><trackback:ping>http://www.aygfsteel.com/liuyf8688/services/trackbacks/408469.html</trackback:ping><description><![CDATA[<div><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;"><strong>1.单一职责原则(Single Responsibility Principle: SRP)</strong></span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">应该有且仅有一个原因引��L��的变更�?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">===========================================================</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">There should never be more than one reason for a class to change.</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">注：该原则主要用在接口、类和方法中�?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;"><strong>2.里氏替换原则(Liskov Substitution Principle: LSP)</strong></span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">如果�Ҏ��一个类型�ؓS的对象o1�Q�都有类型�ؓT的对象o2�Q���得以T定义的所有程序P在所有的对象o1都替换成o2�Ӟ���E�序P的行��Z��发生��M��变化�Q�那么类型S的类型T的子�c�d���?所有引用基�cȝ��地方必须能透明的��用其子类的对�?</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">===========================================================</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">If for each object o1 of type S there is an object o2 of type T such that for all programs P defined in terms of T, the behavior of P is unchanged where o1 is substituted for o2 then S is a subtype of T.(Functions that use pointers or references to base classes must be able to use object of derived classes without knowing it)</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">注：</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(1)子类必须完全实现父类的方�?如果父类的某些方法在子类中已�l�发�?#8220;畸变&#8221;�Q�则�����断开父子�l�承关系�Q��{而采用依赖、聚集、组合等关系代替�l�承)</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(2)子类可以自由扩展�Q�子�c�d��象可以代替父�c�，但父�c�d��象不能代替子�c�d���?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(3)子类覆盖或者实现父�cȝ���Ҏ��时输入参数可以被攑֤�(子类中的�Ҏ��输入参数可以和父�c�L��法的输入参数同类型，或者是父类�Ҏ��输入参数的父�c�d��。保证如果子�c�M��父类构成重蝲时传入子�c�d��象调用的�Ҏ��仍是父类的方法，如果子类重写了父�cȝ���Ҏ���Q�则传入子类对象调用的方法是子类的方�?</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(4)覆盖或实现父�cȝ���Ҏ��时输出结�?�q�回�?可以被羃��?子类覆写或实现的�Ҏ��的返回值必���M��父类对应�Ҏ��的返回值同�c�d��或者是父类对应�Ҏ��的返回值类型的子类)</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;"><strong>3.依赖倒置原则</strong></span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">原则1�Q�高层模块不应该依赖低层模块�Q�两个都应该依赖抽象</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">原则2�Q�抽象不应该依赖�l�节�Q�细节应该依赖抽�?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;"><strong>4.接口隔离原则</strong></span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">接口隔离的定�?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(1)客户端不应该�����依赖它不需要的接口(Clients should not be forced to depend upon interfaces that they don't use)</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(2)�c�间的依赖关�p�d��该徏立在最���的接口�?The dependency of one class to another one should depend on the smallest possible interface)</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">===========================================================</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">�q�里的接口是指：</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(1)对象接口(Object Interface)</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(2)�c�L���?Class Interface)</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">===========================================================</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">接口隔离原则使用时的规范�Q?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(1)接口���量��?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(2)接口高内�?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">(3)接口设计有限�?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;"><strong>5.�q�米�Ҏ���?Least Knowledge Principle: LKP)</strong></span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">&#8220;最���知识原�?#8221;�Q�一个对象对其它对象有最���的了解�Q�即一个类应该对自己需要耦合或调用的�cȝ��道得最���，只需要知道它所提供的接口就行�?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">===========================================================</span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">�q�分使用�q�米特原则，会��生大量这��L��中介和传递类�Q�导致系�l�复杂度变大。所以采用时要反复权衡，既做到结构清晎ͼ�又要高内聚低耦合�?/span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;"><strong>6.开闭原�?/strong></span><br style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: medium;" /><span style="font-family: Tahoma; line-height: normal; orphans: 2; text-align: -webkit-auto; widows: 2; font-size: 10pt;">用抽象构建框�Ӟ��用实现扩展细节�?/span></div><img src ="http://www.aygfsteel.com/liuyf8688/aggbug/408469.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.aygfsteel.com/liuyf8688/" target="_blank">风沙</a> 2014-01-04 09:19 <a href="http://www.aygfsteel.com/liuyf8688/articles/408469.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>                                                                            <footer>
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