设计模式原则之：里氏替换原则

示例已发推论

 

/**
 * @description: 示例引发里氏替换原则的实现
 * @author: abel.he
 * @date: 2023-08-03
 **/
public class Test1 {

    public static void main(String[] args) {
        Person person = new Person();
        System.out.println("9 + 2 = " + person.calc(9, 2));

        Child child = new Child();
        // 这里本意是求出9+2 的和
        System.out.println("9 + 2 = " + child.calc(9, 2));
    }

}

class Person {

    public int calc(int a, int b) {
        return a + b;
    }
}

class Child extends Person {

    public int calc(int a, int b) {
        return a - b;
    }

    public int calc1(int a, int b) {
        return calc(a, b) + 9;
    }

}

 

里氏替换原则优化

 

/**
 * @description: 里氏替换原则的实现
 * @author: abel.he
 * @date: 2023-08-03
 **/
public class Test1 {

    public static void main(String[] args) {
        Person person = new Person();
        System.out.println("9 + 2 = " + person.calc(9, 2));

        Child child = new Child();
        // 这里本意是求出9+2 的和
        System.out.println("9 - 2 = " + child.calc(9, 2));

        System.out.println("9 + 2 = " + child.calc2(9, 2));
    }

}

class Base {

}

class Person extends Base {

    public int calc(int a, int b) {
        return a + b;
    }
}

class Child extends Base {

    private Person person = new Person();

    public int calc(int a, int b) {
        return a - b;
    }

    public int calc1(int a, int b) {
        return calc(a, b) + 9;
    }

    public int calc2(int a, int b) {
        return person.calc(a, b);
    }

}