三个包：xiaomu、xiaomuuncle、lanwang
xiaomu包下三个类：Grandpa、Son、Xiaomu
xiaomuuncle包下两个类：Uncle、UncleSon
lanwang包下两个类：Brother、LaoWang
在三个包外有个测试类：SecretRecipeTest
运行结果为：
小慕儿子获取到–小慕家的祖传秘方：慕氏秘方
小慕获取到–小慕家的祖传秘方：慕氏秘方
小慕叔叔获取到–小慕家的祖传秘方：慕氏秘方
小慕叔叔儿子获取到–小慕家的祖传秘方：慕氏秘方
小慕兄弟获取到–小慕家的祖传秘方：慕氏秘方
老王–获取不到祖传秘方：慕氏秘方，因为老王没有继承权限
------------------------------------xiaomu包下代码------------------------------
Grandpa类代码：

package com.imooc.test.xiaomu;

public class Grandpa {
    private String secretRecipe = "慕氏秘方";
    protected void showSecretRecipe() {
        System.out.println("小慕家的祖传秘方：" + secretRecipe);
    }

}

Xiaomu类代码：

package com.imooc.test.xiaomu;

public class Xiaomu extends Grandpa{
    private String name;

    public Xiaomu(String name) {
        this.name = name;
    }

    public Xiaomu() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void name() {
        System.out.print(name + "获取到--");
        showSecretRecipe();
    }
}

Son类代码：

package com.imooc.test.xiaomu;

public class Xiaomu extends Grandpa{
    private String name;

    public Xiaomu(String name) {
        this.name = name;
    }

    public Xiaomu() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void name() {
        System.out.print(name + "获取到--");
        showSecretRecipe();
    }
}

------------------------------------xiaomuuncle包下代码------------------------------
Uncle类代码：

package com.imooc.test.xiaomuuncle;

import com.imooc.test.xiaomu.Grandpa;

public class Uncle extends Grandpa {
    private String name;

    public Uncle(String name) {
        this.name = name;
    }

    public Uncle() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    public void name() {
        System.out.print(name + "获取到--");
        showSecretRecipe();
    }
}

UncleSon类代码：

package com.imooc.test.xiaomuuncle;

public class UncleSon extends Uncle{
    private String name;
    public UncleSon(String name) {
        this.name = name;
    }
    public UncleSon() {
    }

    @Override
    public String getName() {
        return name;
    }

    @Override
    public void setName(String name) {
        this.name = name;
    }
    public void name() {
        System.out.print(name + "获取到--");
        showSecretRecipe();
    }
}

------------------------------------lanwang包下代码------------------------------
Brother类代码：

package com.imooc.test.laowang;

import com.imooc.test.xiaomu.Grandpa;

public class Brother extends Grandpa {
    private String name;

    public Brother(String name) {
        this.name = name;
    }

    public Brother() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void name() {
        System.out.print(name + "获取到--");
        showSecretRecipe();
    }
}

LaoWang类代码：

package com.imooc.test.laowang;

public class LaoWang {
    private String name;

    public LaoWang(String name) {
        this.name = name;
    }

    public LaoWang() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    public void name() {
        System.out.print(name + "--获取不到祖传秘方：慕氏秘方，因为老王没有继承权限");
        // 必须要注销掉，否则会报错，因为protected权限，在不同包中，只有子类才能调用
        //showSecretRecipe();
    }
}

------------------------------------三个包外的测试类：SecretRecipeTest代码------------------------------

package com.imooc.test;

import com.imooc.test.laowang.Brother;
import com.imooc.test.laowang.LaoWang;
import com.imooc.test.xiaomu.Grandpa;
import com.imooc.test.xiaomu.Son;
import com.imooc.test.xiaomu.Xiaomu;
import com.imooc.test.xiaomuuncle.Uncle;
import com.imooc.test.xiaomuuncle.UncleSon;
/*
* 结果为：
小慕儿子获取到--小慕家的祖传秘方：慕氏秘方
小慕获取到--小慕家的祖传秘方：慕氏秘方
小慕叔叔获取到--小慕家的祖传秘方：慕氏秘方
小慕叔叔儿子获取到--小慕家的祖传秘方：慕氏秘方
小慕兄弟获取到--小慕家的祖传秘方：慕氏秘方
老王--获取不到祖传秘方：慕氏秘方，因为老王没有继承权限
* */
public class SecretRecipeTest {
    public static void main(String[] args) {
        Son son = new Son("小慕儿子");
        son.name();
        Xiaomu xiaomu = new Xiaomu("小慕");
        xiaomu.name();
        Uncle uncle = new Uncle("小慕叔叔");
        uncle.name();
        UncleSon uncleSon = new UncleSon("小慕叔叔儿子");
        uncleSon.name();
        Brother brother = new Brother("小慕兄弟");
        brother.name();
        LaoWang laoWang = new LaoWang("老王");
        laoWang.name();
    }
}