设计模式（模板方法）

public abstract class Template {
    public void templateMethod(){
        baseMethod();
        subMehtod();
    }
    
    public void baseMethod(){
        System.out.println("baseMethod");
    }
    
    public abstract void subMehtod();
}

public class ConcreteOne extends Template {

    @Override
    public void subMehtod() {
        System.out.println("ConcreteOne");
    }
}

public class ConcreteTwo extends Template {

    @Override
    public void subMehtod() {
        System.out.println("ConcreteTwo");
    }
}

public class App {

    public static void main(String[] args) {
        Template temp = new ConcreteOne();
        temp.templateMethod();
        temp = new ConcreteTwo();
        temp.templateMethod();
    }
}