在运行时访问注释

Question

我怎样才能访问main是否check在Sample类是真还是假？
我应该在Main类写什么？

    package annotation;

    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;

    @Retention(RetentionPolicy.RUNTIME)

    public @interface annotation {
        public String name() default "Jimmy";
        public boolean check() default false;
    }

---

    package annotation;

    @annotation(name = "Jack", check = false)

    public class Sample {

        public String str = "Hi";

        public void printHi(String str) {
            System.out.println(str);
        }
    }

---

    package annotation;

    public class Main {
        public static void main(String[] args) {

        }
    }

Answer 1

使用Sample.class.getAnnotation(annotation.class)让您的注释实例,并调用check()来获取校验值:

System.out.println(Sample.class.getAnnotation(annotation.class).check());

请注意,类应以大写字母开头,并且命名注释"注释"非常令人困惑.