工厂模式分三种：简单工厂、工厂方法、抽象工厂。其中抽象工厂是用于多个产品族的情况。所谓产品族就是不同产品组成的有机整体，各不同产品之间相互依赖。打个比方，一台电脑有CPU、主板、内存和硬盘等，这些不同产品组成了一个产品族。就好比Dell和HP要把这些产品进行不同的组装，这时就需要用到抽象工厂。以下是代码演示：
简单工厂，可以用反射实现：
首先定义产品的抽象接口
package com.demo.SimpleFactory; public interface CPU { public void run(); }
定义具体产品
package com.demo.SimpleFactory; public class Intel implements CPU { @Override public void run() { // TODO Auto-generated method stub System.out.println("This is Intel!"); } }
package com.demo.SimpleFactory; public class Amd implements CPU { @Override public void run() { // TODO Auto-generated method stub System.out.println("This is Amd!"); } }
定义工厂类
package com.demo.SimpleFactory; public class Factory { public static CPU create(String str) { CPU c = null; try { c = (CPU) Class.forName("com.demo.SimpleFactory." + str) .newInstance(); } catch (Exception e) { e.printStackTrace(); } return c; } }
测试如下
package com.demo.SimpleFactory; public class Test { public static void main(String[] args){ CPU c=Factory.create("Amd"); c.run(); } }
打印结果：
This is Amd!
工厂方法
首先定义产品的抽象接口
package com.demo.SimpleFactory;
public interface CPU {
public void run();
}
定义具体产品
package com.demo.SimpleFactory;
public class Intel implements CPU {
@Override
public void run() {
// TODO Auto-generated method stub
System.out.println("This is Intel!");
}
}
package com.demo.SimpleFactory;
public class Amd implements CPU {
@Override
public void run() {
// TODO Auto-generated method stub
System.out.println("This is Amd!");
}
}
定义抽象工厂，具体现实由其子类负责
package com.demo.FactoryMethod; public interface FactoryMethod { public CPU create(); }
具体子类工厂
package com.demo.FactoryMethod; public class AmdFactory implements FactoryMethod { @Override public CPU create() { // TODO Auto-generated method stub return new Amd(); } }
package com.demo.FactoryMethod; public class IntelFactory implements FactoryMethod { public CPU create() { return new Intel(); } }
测试
package com.demo.FactoryMethod; public class Test { public static void main(String[] args) { FactoryMethod af=new IntelFactory(); CPU c=af.create(); c.run(); } }
打印结果：
This is Intel!
抽象工厂
首先定义产品的抽象接口
package com.demo.SimpleFactory;
public interface CPU {
public void run();
}
定义具体产品
package com.demo.SimpleFactory;
public class Intel implements CPU {
@Override
public void run() {
// TODO Auto-generated method stub
System.out.println("This is Intel!");
}
}
package com.demo.SimpleFactory;
public class Amd implements CPU {
@Override
public void run() {
// TODO Auto-generated method stub
System.out.println("This is Amd!");
}
}
package com.demo.AbstractFactory; public interface Memory { public void read(String str); }
package com.demo.AbstractFactory; public class KingstonMemory implements Memory { public KingstonMemory() { // TODO Auto-generated constructor stub } @Override public void read(String str) { // TODO Auto-generated method stub System.out.println("Kingston Read data is:"+str); } }
package com.demo.AbstractFactory; public class AdataMemory implements Memory { public AdataMemory() { // TODO Auto-generated constructor stub } @Override public void read(String str) { // TODO Auto-generated method stub System.out.println("Adata read data is:"+str); } }
定义抽象工厂
package com.demo.AbstractFactory; public interface AbstractFactory { public CPU createCPU(); public Memory createMemory(); }
不同子类产生不同产品族
package com.demo.AbstractFactory; public class DellFactory implements AbstractFactory { @Override public CPU createCPU() { // TODO Auto-generated method stub return new Intel(); } @Override public Memory createMemory() { // TODO Auto-generated method stub return new KingstonMemory(); } }
package com.demo.AbstractFactory; public class HPFactory implements AbstractFactory { @Override public CPU createCPU() { // TODO Auto-generated method stub return new Amd(); } @Override public Memory createMemory() { // TODO Auto-generated method stub return new AdataMemory(); } }
测试
package com.demo.AbstractFactory; public class Test { public static void main(String[] args){ AbstractFactory hp=new HPFactory(); CPU cpu=hp.createCPU(); Memory memory=hp.createMemory(); cpu.run(); memory.read("Pass"); } }
打印结果：
This is Amd!
Adata read data is:Pass