Factory pattern pattern pattern (simple factory, factory method, abstract factory pattern)

Three design patterns related to the factory  2020-11-08 15:03:29

Simple factory model ： To put it bluntly , Indirectly out of new Create objects , It's about getting objects directly from the factory .

Simple factory ： Not with new Create objects , Instead, the process of creating objects is centralized in the factory , This makes it easy to maintain the change creation process ; It also realizes the decoupling between the call creation object and the object .

Don't talk much , Let's start with the following UML Class diagram ：

                

 

 Automobile 
package com.yuan.factory.simple;

public abstract  class Car {

    public abstract void getname();

}

 Volkswagen class 

package com.yuan.factory.simple;

public class Dazong extends Car {

    @Override
    public void getname() {
        System.out.println(" The public ");
    }
}

 Tesla cars 

package com.yuan.factory.simple;

public class Tsla extends Car {
    @Override
    public void getname() {
        System.out.println(" tesla ");
    }
}

 Automobile factories 

package com.yuan.factory.simple;

public class CarFactory {

    public static Car getTsla(){
        return new Tsla();
    }


    public static Car getDazong(){
        return new Dazong();
    }

}

 Customer class 

package com.yuan.factory.simple;

public class Customer {
    public static void main(String[] args) {
        CarFactory carFactory = new CarFactory();
        carFactory.getTsla().getname();
        carFactory.getDazong().getname();
    }
}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Factory method model ：

　　 Because of the simple factory model , dissatisfaction “ Open to expansion , Turn off for changes ” principle , So , There's the factory approach model . Then the factory approach pattern is on the simple factory model , Create a factory for each subclass , So it's scalable , Follow these principles .

 

 Bus interface 
package com.yuan.factory.method;

public interface Car {

    void getname();
}

 Volkswagen class 

package com.yuan.factory.method;

public class Dazong implements Car {
    @Override
    public void getname() {
        System.out.println(" The public ");
    }
}
 Tesla cars 

package com.yuan.factory.method;

public class Tsla implements Car {
    @Override
    public void getname() {
        System.out.println(" tesla ");
    }
}

 Car factory interface 

package com.yuan.factory.method;

public interface CarFactory {

    Car getCar();
}
 Volkswagen factory 

package com.yuan.factory.method;

public class  DazongFactory implements CarFactory {


    @Override
    public  Car getCar() {
        return new Dazong();
    }
}

 Tesla automobile factory 

package com.yuan.factory.method;

public class TslaFactory implements CarFactory{

    @Override
    public  Car getCar() {
        return new Tsla();
    }
}

 Customer class 

package com.yuan.factory.method;

public class Customer {

    public static void main(String[] args) {
        new DazongFactory().getCar().getname();
        new TslaFactory().getCar().getname();
    }
}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Abstract factory pattern ：

Product family ： Different types of products produced by the same manufacturer .

Same product type ： A little ... A little ... A little

　　　　 Abstract factory pattern （Abstract Factory Pattern） It's about creating other factories around one super factory . This super factory is also called the factory of other factories . This type of design pattern is a creation pattern , It provides the best way to create objects .

　　　　 In abstract factory mode , Interface is the factory responsible for creating a related object , There is no need to explicitly specify their classes . Each generated factory can provide objects according to the factory pattern .