我没有在 Java 中获得 @Inherited
注释.如果它自动为您继承方法,那么如果我需要以自己的方式实现该方法,那又如何呢?
I am not getting the @Inherited
annotation in Java. If it automatically inherits the methods for you then if I need to implement the method in my own way then what about that ?
它将如何知道我的实现方式?
How does will it come to know my way of implementation ?
另外据说如果我不想使用它,而是以老式的 Java 方式来做,我必须实现 equals()
、toString()
,Object
类的hashCode()
方法,以及java.lang.annotation.Annotation
类的注解类型方法.
Plus it is said if I do not want to use this and do it rather in an old fashioned Java way I have to implement the the equals()
, toString()
, and the hashCode()
methods of the Object
class and also the annotation type method of the java.lang.annotation.Annotation
class.
这是为什么呢?
即使我不知道 @Inherited
注释和过去也可以正常工作的程序,我也从未实现过这些.
I have never implemented those even when I did not know about the @Inherited
annotation and the programs used to work fine also .
请有人从头开始解释一下.
Please somebody explain me from the scratch about this.
只是没有误会:你确实问java.lang.annotation.Inherited.这是注解的注解.表示被注解的类的子类被认为与它们的超类具有相同的注解.
Just that there is no misunderstanding: You do ask about java.lang.annotation.Inherited. This is a annotation for annotations.It means that subclasses of annotated classes are considered having the same annotation as their superclass.
考虑以下 2 个注释:
Consider the following 2 Annotations:
@Inherited
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface InheritedAnnotationType {
}
和
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface UninheritedAnnotationType {
}
如果三个类是这样注释的:
If three classes are annotated like this:
@UninheritedAnnotationType
class A {
}
@InheritedAnnotationType
class B extends A {
}
class C extends B {
}
运行此代码
System.out.println(new A().getClass().getAnnotation(InheritedAnnotationType.class));
System.out.println(new B().getClass().getAnnotation(InheritedAnnotationType.class));
System.out.println(new C().getClass().getAnnotation(InheritedAnnotationType.class));
System.out.println("_________________________________");
System.out.println(new A().getClass().getAnnotation(UninheritedAnnotationType.class));
System.out.println(new B().getClass().getAnnotation(UninheritedAnnotationType.class));
System.out.println(new C().getClass().getAnnotation(UninheritedAnnotationType.class));
会打印出类似这样的结果(取决于注解的包):
will print a result similar to this (depending on the packages of the annotation):
null
@InheritedAnnotationType()
@InheritedAnnotationType()
_________________________________
@UninheritedAnnotationType()
null
null
如您所见,UninheritedAnnotationType
没有被继承,但 C
从 B
继承注释 InheritedAnnotationType
.
As you can see UninheritedAnnotationType
is not inherited but C
inherits annotation InheritedAnnotationType
from B
.
我不知道这与什么方法有关.
这篇关于如何在 Java 中使用 @inherited 注解?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持跟版网!