StandardMBeanIntrospector.java 文件源码

static boolean isDefinitelyImmutableInfo(Class<?> implClass) {
    if (!NotificationBroadcaster.class.isAssignableFrom(implClass))
        return true;
    synchronized (definitelyImmutable) {
        Boolean immutable = definitelyImmutable.get(implClass);
        if (immutable == null) {
            final Class<NotificationBroadcasterSupport> nbs =
                    NotificationBroadcasterSupport.class;
            if (nbs.isAssignableFrom(implClass)) {
                try {
                    Method m = implClass.getMethod("getNotificationInfo");
                    immutable = (m.getDeclaringClass() == nbs);
                } catch (Exception e) {
                    // Too bad, we'll say no for now.
                    return false;
                }
            } else
                immutable = false;
            definitelyImmutable.put(implClass, immutable);
        }
        return immutable;
    }
}