注解的基本知识

 1 @Documented
 2 @Retention(RetentionPolicy.RUNTIME)
 3 @Target(value={CONSTRUCTOR, FIELD, LOCAL_VARIABLE, METHOD, PACKAGE, MODULE, PARAMETER, TYPE})
 4 public @interface Deprecated {
 5     /**
 6      * Returns the version in which the annotated element became deprecated.
 7      * The version string is in the same format and namespace as the value of
 8      * the {@code @since} javadoc tag. The default value is the empty
 9      * string.
10      *
11      * @return the version string
12      * @since 9
13      */
14     String since() default "";
15 
16     /**
17      * Indicates whether the annotated element is subject to removal in a
18      * future version. The default value is {@code false}.
19      *
20      * @return whether the element is subject to removal
21      * @since 9
22      */
23     boolean forRemoval() default false;
24 }