php设计模式(3)工厂模式之工厂方法模式

<h1 style="position: relative; margin: 1em 0px; font-size: 18px; line-height: 24px; padding-left: 12px; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">前言：</h1><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">上一节我们讨论了简单工厂模式，这一节我们继续讨论工厂模式中的第二种模式——工厂方法模式。需要说明一下，简单工厂模式比较常用，工厂方法和抽象工厂模式用的比较少一些。</p><h1 style="position: relative; margin: 1em 0px; font-size: 18px; line-height: 24px; padding-left: 12px; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">内容概要：</h1><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">1、什么是是工厂方法模式</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">2、怎么实现工厂方法模式</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">3、示例代码</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);"><span style="font-size: 18px;">一、什么是工厂方法模式</span></p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">工厂方法模式是对每一种产品（相关联的产品）提供一个工厂类，调用放通过不同的工厂类来创建不同的产品实例。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">举个例子，上回我们说到的冰激凌工厂现在扩大规模，投资在另一个地方又建立了一个冰激凌工厂,生产的产品都是冰激凌，产品种类也都是一样的：苹果味的和牛奶味的。但是这两种产品的生产地址是不同的。我们希望客户能够就近购买冰激凌。这时候就需要使用工厂方法模式了，通过不同的工厂类创建获得不同的产品实例（冰激凌）。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">一句话：冰激凌开设分厂的时候用到工厂方法模式。</p><h1 style="position: relative; margin: 1em 0px; font-size: 18px; line-height: 24px; padding-left: 12px; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">二、怎么实现工厂方法模式</h1><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">实现工厂方法，牵扯到几个概念：抽象工厂，具体工厂，抽象产品，具体产品，我们一起了解一下。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">1、抽象工厂，我们可以理解成两个冰激凌工厂的上级部门，这里假设称为总公司。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">2、具体工厂，两个冰激凌工厂.</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">3、抽象产品，我们说“冰激凌”这个词就是抽象产品，这个词不能吃，但是却规定了冰激凌生产的配料标准，操作规范，冰激凌重量尺寸等等。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">4、具体产品，用户实实在在拿在手里可以吃的冰激凌。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">好了，对应好关系后，我们开始和php编码联系一下。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">首先我们需要一个工厂的接口（或者一个抽象类，或两者都有）类，用于给各个具体工厂规定条条框框。也就是说，每个冰激凌分厂，要根据总公司的规定生产。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">其次，我们给每个具体工厂创建一个类，用于实例化产品，必须实现工厂接口。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">然后，我们还要建立一个产品的抽象类（或者接口，或者两者都有。）内容规定产品的规格等的代码</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">最后，创建具体产品的类描，必须继承产品抽象类。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">大家可以找个UML图看看，我这里就不画了。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">有点晕吧？恩，看代码的命!</p><h1 style="position: relative; margin: 1em 0px; font-size: 18px; line-height: 24px; padding-left: 12px; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">三、示例代码</h1><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">我把类全写在一个文件中哈，理由参考上一节。</p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);"><img src="/Uploads/ueditor/image/20170305/1488708654980548.png" title="1488708654980548.png" alt="blob.png"/></p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);"><img src="/Uploads/ueditor/image/20170305/1488708677261036.png" title="1488708677261036.png" alt="blob.png"/></p><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);"><img src="/Uploads/ueditor/image/20170305/1488708691911401.png" title="1488708691911401.png" alt="blob.png"/></p><hr/><p style="margin-top: 1em; margin-bottom: 1em; word-wrap: break-word; text-align: justify; line-height: 1.5; color: rgb(93, 93, 93); font-family: helvetica, Arial, "Hiragino Sans GB", "Microsoft YaHei", simsun; white-space: normal; background-color: rgb(255, 255, 255);">码字不容易，尊重版权，今日头条首发，转载请注明出处：头条号|PHP在路上。</p><p><br/></p>