模版模式

类图

模版模式.png

实现

调用

package com.company;

public class Main {

    public static void main(String[] args) {
    // write your code here
        GeneralClass general = new GeneralClass();
        general.doIt();

        System.out.println("++++++++++++++++++++");

        GeneralClass elephant = new ElephantClass();
        elephant.doIt();

        System.out.println("++++++++++++++++++++");

        GeneralClass apple = new AppleClass();
        apple.doIt();
    }
}

输出

把冰箱门打开
把某东西装进去
把冰箱门带上
++++++++++++++++++++
把冰箱门打开
把大象装进去
把冰箱门带上
++++++++++++++++++++
把冰箱门打开
把苹果装进去
把冰箱门带上

Process finished with exit code 0

把某东西装进冰箱的类

package com.company;

/**
 * 把某东西装冰箱
 */
public class GeneralClass {
    protected void openFridge() {
        System.out.println("把冰箱门打开");
    }

    protected void closeFridge() {
        System.out.println("把冰箱门带上");
    }

    protected void putSomethingIn() {
        System.out.println("把某东西装进去");
    }

    /**
     * 这个就是那个hook方法。
     * 在这里我不重写它，所此处用final修饰。
     */
    public final void doIt() {
        this.openFridge();
        this.putSomethingIn();
        this.closeFridge();
    }
}

把大象装冰箱

package com.company;

public class ElephantClass extends GeneralClass {
    @Override
    protected void putSomethingIn() {
        System.out.println("把大象装进去");
    }
}

把苹果装冰箱

package com.company;

public class AppleClass extends GeneralClass {
    @Override
    protected void putSomethingIn() {
        System.out.println("把苹果装进去");
    }
}

The Template Method Pattern——Encapsulating Algorithm