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