Java 开发 - Java 继承后成员的隐藏与重写

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

成员	示例 1	示例 2
静态变量	继承父类	隐藏父类
静态方法	继承父类	隐藏父类
实例变量	继承父类	隐藏父类
实例方法	继承父类	重写父类