设计模式之简单工厂

简单工厂模式：由一个工厂对象决定创建出哪一种类的实例。

1.抽象类

public abstract class People {
    public  abstract void doSth();
}

2.具体类

public class Man extends People{
    @Override
    public void doSth() {
        System.out.println("I'm a man,I'm coding.");
    }
}

3.具体类

public class Girl extends People{

    @Override
    public void doSth() {
        System.out.println("I'm a girl,I'm eating.");
    }
}

4.工厂

public class PeopleFactory {

    public static People getSpecificPeople(String type){
        if("A-Man".equals(type)){
            return new Man();
        }else if("B-Girl".equals(type)){
            return new Girl();
        }else {
            return null;
        }
    }
}

5.测试代码

public class PeopleTestDemo {
    public static void main(String[] args) {
        People man = PeopleFactory.getSpecificPeople("A-Man");
        Objects.requireNonNull(man,"对象不存在.");
        man.doSth();

        People girl = PeopleFactory.getSpecificPeople("B-Girl");
        Objects.requireNonNull(girl,"对象不存在");
        girl.doSth();

        People foodie = PeopleFactory.getSpecificPeople("Foodie");
        Objects.requireNonNull(foodie,"对象不存在");
        foodie.doSth();
    }
}