Java设计模式之简单工厂 工厂方法 抽象工厂深度总结

目录

• 工厂模式介绍
  • 好处
  • 常见的应用
• 简单工厂（Simple Factory）
  • 适用场景
  • 角色分配：
  • 应用案例：
  • 优缺点：
  • 简单工厂实现：
• 工厂方法（Factory Method）
  • 适用场景
  • 角色分配：
  • 应用案例：
  • 优缺点：
  • 工厂方法实现：
• 抽象工厂（Abstract Factory）
  • 适用场景
  • 角色分配
  • 应用案例：
  • 优缺点：
  • 抽象工厂实现
  • 抽象工厂终极改进（反射+配置文件+简单工厂）

//创建连接工厂
ConnectionFactory factory = new ConnectionFactory("192.168.74.4");
// 通过连接工厂获取连接
Connection connection = factory.newConnection();

package com.wkp.designpattern.factory;
//汽车接口
public interface Car {
 
	//返回汽车的品牌
	public String getName();
}

package com.wkp.designpattern.factory;
 
public class Audi implements Car {
 
	public String getName() {
		return "Audi";
	}
}

package com.wkp.designpattern.factory;
 
public class Bmw implements Car {
 
	public String getName() {
		return "Bmw";
	}
}

package com.wkp.designpattern.simple.factory;
 
import com.wkp.designpattern.factory.Audi;
import com.wkp.designpattern.factory.Bmw;
import com.wkp.designpattern.factory.Car;
 
public class SimpleFactory {
 
	public Car getCar(String name){
		if("Audi".equals(name)){
			return new Audi();
		}else if("Bmw".equals(name)){
			return new Bmw();
		}else{
			System.out.println("没法生产这个车");
			return null;
		}
	}
}

package com.wkp.designpattern.simple.factory;
import com.wkp.designpattern.factory.Car;
 
public class SimpleFactoryTest {
 
	public static void main(String[] args) {
		SimpleFactory factory = new SimpleFactory();
		
		Car car1 = factory.getCar("Audi");
		System.out.println(car1.getName());
		Car car2 = factory.getCar("Bmw");
		System.out.println(car2.getName());
	}
}

//利用反射改进的简单工厂，添加的时候不用修改getCar方法
public class ReflectSimpleFactory {
 
	//参数className为完整类名
	public Car getCar(String className){
		Car obj=null;
		try {
			obj=(Car) Class.forName(className).newInstance();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		return obj;
	}
}

public class ReflectSimpleFactoryTest {
 
	public static void main(String[] args) {
		ReflectSimpleFactory factory = new ReflectSimpleFactory();
		Car car1 = factory.getCar("com.wkp.designpattern.factory.Audi");
		System.out.println(car1.getName());
		Car car2 = factory.getCar("com.wkp.designpattern.factory.Bmw");
		System.out.println(car2.getName());
	}
}

public interface Factory {
 
	public Car getCar();
}

public class AudiFactory implements Factory {
 
	public Car getCar() {
		return new Audi();
	}
}

public class BmwFactory implements Factory {
 
	public Car getCar() {
		return new Bmw();
	}
}

public class FuncFactoryTest {
 
	public static void main(String[] args) {
		Car car1 = new AudiFactory().getCar();
		System.out.println(car1.getName());
		
		Car car2 = new BmwFactory().getCar();
		System.out.println(car2.getName());
	}
}

//CPU
public interface CPU {
 
	public String getName();
}

//主板
public interface MainBoard {
 
	public String getName();
}

public class IntelCPU implements CPU {
 
	public String getName() {
		return "IntelCPU";
	}
 
}

public class IntelMainBoard implements MainBoard{
 
	public String getName() {
		return "IntelMainBoard";
	}
 
}

public class AMDCPU implements CPU {
 
	public String getName() {
		return "AMDCPU";
	}
 
}

public class AMDMainBoard implements MainBoard{
 
	public String getName() {
		return "AMDMainBoard";
	}
 
}

public interface Factory {
	//生产CPU
	public CPU createCPU();
	//生产主板
	public MainBoard createMainBoard();
}

//Intel系列产品工厂
public class IntelFactory implements Factory {
 
	public CPU createCPU() {
		return new IntelCPU();
	}
 
	public MainBoard createMainBoard() {
		return new IntelMainBoard();
	}
 
}

//AMD系列产品工厂
public class AMDFactory implements Factory {
 
	public CPU createCPU() {
		return new AMDCPU();
	}
 
	public MainBoard createMainBoard() {
		return new AMDMainBoard();
	}
 
}

public class FactoryTest {
 
	public static void main(String[] args) {
		Factory intel = new IntelFactory();
		System.out.println(intel.createCPU().getName());
		System.out.println(intel.createMainBoard().getName());
		
		Factory amd = new AMDFactory();
		System.out.println(amd.createCPU().getName());
		System.out.println(amd.createMainBoard().getName());
	}
}

type=Intel
packageName=com.wkp.design.pattern.factory.abst

public class SimpleFactory {
 
	static class Configuration{
		public static String get(String key){
			String value="";//TODO 读取配置文件得到value
			return value;
		}
	}
	
	//通过配置文件读取产品族类型及包名
	private static final String type=Configuration.get("type");
	private static final String packageName=Configuration.get("packageName");
	
	//生产CPU
	public CPU createCPU() throws Exception{
		return (CPU)Class.forName(packageName+"."+type+"CPU").newInstance();
	}
	//生产主板
	public MainBoard createMainBoard() throws Exception{
		return (MainBoard)Class.forName(packageName+"."+type+"MainBoard").newInstance();
	}
}

public class SimpleFactoryTest {
 
	public static void main(String[] args) throws Exception {
		SimpleFactory factory = new SimpleFactory();
		System.out.println(factory.createCPU().getName());
		System.out.println(factory.createMainBoard().getName());
	}
}