JAVA设计模式温故篇-工厂模式

工厂模式定义了一个创建对象的接口，但由子类决定要实例化的类是哪一个。工厂方法让类把实例化推迟到子类。

举个很简单的例子，中国生产了一批布，可以制作成衣服和裤子，并且在中国和美国都有工厂，可以这样定义类

定义一个抽象工厂类，用于定义方法，但具体的操作由各个分工厂自己操作

package com.hpg.demo.cloth;public abstract class Factory {public Cloth orderCloth(String JacketOrTrouse) {Cloth cloth;cloth = createCloth(JacketOrTrouse);cloth.make();cloth.labeling();return cloth;}public abstract Cloth createCloth(String JacketOrTrouse);}

定义一个Cloth类，Jacket和Trouse都继承这个类

package com.hpg.demo.cloth;public abstract class Cloth {/** * 衣服还是裤子 */String typeName ;/** * 制作 */void make(){System.out.println("simple make");}/** * 贴标签 */void labeling(){System.out.println("simple labeling");}}

定义AmericaFactory类

package com.hpg.demo.cloth;public class AmericaFactory extends Factory {@Overridepublic Cloth createCloth(String JacketOrTrouse) {if (JacketOrTrouse.equals("jacket")) {return new Jacket();} else if (JacketOrTrouse.equals("trouse")) {return new Trouse();} else {return null;}}}

定义ChinaFactory类

package com.hpg.demo.cloth;public class ChinaFactory extends Factory{@Overridepublic Cloth createCloth(String JacketOrTrouse) {if (JacketOrTrouse.equals("jacket")) {return new Jacket();} else if (JacketOrTrouse.equals("trouse")) {return new Trouse();} else {return null;}}}

定义Jacket类

package com.hpg.demo.cloth;public class Jacket extends Cloth{public Jacket(){typeName = "jacket";}@Overridevoid make() {System.out.println("make:"+typeName);}}

定义Trouse类

package com.hpg.demo.cloth;public class Trouse extends Cloth{public Trouse(){typeName = "trouse";}@Overridevoid make() {System.out.println("make:"+typeName);}}

测试类TestMain

package com.hpg.demo.cloth;public class TestMain {public static void main(String args[]){Factory factory = new ChinaFactory();factory.orderCloth("jacket");}}

执行结果：

make:jacket
simple labeling