工厂模式

分为3种：简单工厂模式、工厂方法模式、抽象工厂模式

• 简单工厂：能简单就简单，在允许的情况下尽可能的简单，但当有复杂的多层次等级结构时，所有的业务逻辑都在这个工厂类中判断实现，一旦这个工厂不能正常工作，整个系统都会受到影响

public class A {
  public static void main(String[] args) {
    Factory factory = newFactory();
    System.out.println(factory.productString("蔬菜"));
    System.out.println(factory.productString("米饭"));
    System.out.println(factory.productInteger("一"));
    System.out.println(factory.productInteger("五"));
    }
}
 
public class Factory {
    public String productString(String inputStr) {
    if (inputStr.equals("水果"))
       return "生产的水果";
    if (inputStr.equals("蔬菜"))
       return "生产的蔬菜";
    return "请输入正确需求";
}
 
public Integer productInteger(String inputStr) {
    if (inputStr.equals("一"))
        return 1;
    if (inputStr.equals("二"))
        return 2;
    return 0;
    }
}
    

 

• 工厂方法模式：定义一个工厂接口，不同的工厂继承这个接口创建不同的产品

//抽象产品类
abstract class Product{
    public abstract void show();
}
//A产品
class ProductA extends Product{
    public void show(){
    System.out.println("这是A产品");
    }
}
//B产品
class ProductB extends Product{
    public void show(){
    System.out.println("这是B产品");
    }
}
//抽象工厂类
abstract class Factory{
    public abstract Product manuPro();
}
//A工厂
class FactoryA extends Factory{
    public Product manuPro(){
    return new ProductA();
    }
}
//B工厂
class FactoryB extends Factory{
    public Product manuPro(){
    return new ProductB();
    }
}
 
//主类
public class Main{
      public static void main(String[] args) {
    //A工厂生产A产品
    FactoryA factoryA=new FactoryA();
    Product product=factoryA.manuPro();
    product.show();//"这是A产品"
    //B工厂生产B产品
    FactoryB factoryB=new FactoryB();
    product=factoryB.manuPro();
    product.show();//"这是B产品"
　　　}
}    

 

 

• 抽象工厂模式:工厂方法模式侧重于同属性产品，而抽象工厂模式侧重于产品族不同属性的产品

类结构如下图：

 

 

//空调
public interface AirConditioner {
    void msg();
}
//风扇
public interface Fan {
    void msg();
}
//冰箱
public interface Fridge {
    void msg();
}

//创建3个美的产品类
public class MediaAirConditioner implements AirConditioner {
    public void msg() {
        System.out.println("美的空调");
    }
}
public class MediaFan implements Fan {
    public void msg() {
        System.out.println("美的风扇");
    }
}
public class MediaFridge implements Fridge{
    public void msg() {
        System.out.println("美的冰箱");
    }
}

//工厂抽象类
public interface Factory {
    Fridge createFridge();
    AirConditioner createAirConditioner();
    Fan createFan();
}

//美的工厂类
public class MediaFactory implements Factory{
    public Fridge createFridge() {
        return new MediaFridge();
    }
    public AirConditioner createAirConditioner() {
        return new MediaAirConditioner();
    }
    public Fan createFan() {
        return new MediaFan();
    }
}

//创建3个海尔产品类
public class haierAirConditioner implements AirConditioner {
    public void msg() {
        System.out.println("海尔空调");
    }
}
public class  haierFan implements Fan {
    public void msg() {
        System.out.println("海尔风扇");
    }
}
public class  haierFridge implements Fridge{
    public void msg() {
        System.out.println("海尔冰箱");
    }
}
//海尔工厂类
public class HaierFactory implements Factory{
    public Fridge createFridge() {
        return new haierFridge();
    }
    public AirConditioner createAirConditioner() {
        return new haierAirConditioner();
    }
    public Fan createFan() {
        return new haierFan();
    }
}


//主类
public class Main{
　　　　public static void main(String[] args) {
    //美的工厂类负责生产美的空调、风扇、冰箱
    Factory mediaFactory=new MediaFactory();
    AirConditioner mediaAirConditioner=mediaFactory.createAirConditioner();
    mediaAirConditioner.msg();//美的空调
    Fan  mediaFan=mediaFactory. createFan();
    mediaFan.msg();//美的风扇
    Fridge mediaFridge=mediaFactory.  createFridge();
    mediaFridge.msg();//美的冰箱


    //海尔工厂类负责生产海尔空调、风扇、冰箱
    Factory haierFactory=new HaierFactory();
    AirConditioner haierAirConditioner=haierFactory.createAirConditioner();
    haierAirConditioner.msg();//海尔空调
    Fan  haierFan=haierFactory.createFan();
    haierFan.msg();//海尔风扇
    Fridge haierFridge=haierFactory.createFridge();
    haierFridge.msg();//海尔冰箱
　　　　}
}