Java 继承后成员的隐藏与重写

1、子类没有定义成员

1. BaseCommonStore.java

public class BaseCommonStore {
    public static final String TAG = "TAG:" + BaseCommonStore.class.getSimpleName();

    public static void sayHello() {
        System.out.println(TAG + " sayHello");
    }

    public String tag = "tag:" + BaseCommonStore.class.getSimpleName();

    public void sayOk() {
        System.out.println(tag + " sayOk");
    }
}

2. CommonStore.java

public class CommonStore extends BaseCommonStore {
}

3. test

System.out.println(CommonStore.TAG);
CommonStore.sayHello();

CommonStore commonStore = new CommonStore();

System.out.println(commonStore.tag);
commonStore.sayOk();

# 输出结果

TAG:BaseCommonStore
TAG:BaseCommonStore sayHello
tag:BaseCommonStore
tag:BaseCommonStore sayOk

2、子类定义同名成员

1. BaseCommonStore.java

public class BaseCommonStore {
    public static final String TAG = "TAG:" + BaseCommonStore.class.getSimpleName();

    public static void sayHello() {
        System.out.println(TAG + " sayHello");
    }

    public String tag = "tag:" + BaseCommonStore.class.getSimpleName();

    public void sayOk() {
        System.out.println(tag + " sayOk");
    }
}

2. CommonStore.java

public class CommonStore extends BaseCommonStore {
    public static final String TAG = "TAG:" + CommonStore.class.getSimpleName();

    public static void sayHello() {
        System.out.println(TAG + " sayHello");
    }

    public String tag = "tag:" + CommonStore.class.getSimpleName();

    public void sayOk() {
        System.out.println(tag + " sayOk");
    }
}

3. test

System.out.println(CommonStore.TAG);
CommonStore.sayHello();

CommonStore commonStore = new CommonStore();

System.out.println(commonStore.tag);
commonStore.sayOk();

# 输出结果

TAG:CommonStore
TAG:CommonStore sayHello
tag:CommonStore
tag:CommonStore sayOk

小结