自定義註解示例：

import java.lang.annotation.*;
@Target(value = {ElementType.METHOD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface MyFactory {
    String name() default "aa";
    String val();
}


@MyFactory(val = "12")
public class student implements Serializable {
}


import java.lang.annotation.Annotation;
public class Test {
    public static void main(String[] args) {
        Class<student> c=student.class;
        Annotation a=c.getAnnotation(MyFactory.class);
        System.out.println(a);
        System.out.println(((MyFactory) a).name());
        System.out.println(((MyFactory) a).val());
    }
}
 

執行結果：

@other.annotation.MyFactory(name=aa, val=12)
aa
12

使用@interface標註的MyFactory自動繼承Annotation介面：