Java Reference
In-Depth Information
Table 6.2
The class members of the
javax.management.Notification
class
Class member
Purpose
A
String
object representing a message. This could be the reason for
the notification.
Message
A number indicating the order in relation of events from the source. The
source populates this field if it intends to give listeners the ability to
sort incoming notifications. The notification model makes no guaranties
that notifications will be received in the order they were sent.
SequenceNumber
The timestamp of the notification, represented as a
long
value.
TimeStamp
The dot-separated
String
value indicating the type of the notification.
Not a class type. For example:
acme.mbeanA.event1
.
Type
An object used to contain any data that a source wants to send to a
notification listener.
UserData
The source of the notification. This object contains an
ObjectName
or
a reference to the object that generated the notification.
Source
6.2.4
Being a notification listener
Up to now, we have examined notification broadcasters, the
MBeanNotification-
Info
class, and the
Notification
class. The last major component in the notifica-
tion framework is the notification listener. In
JMX
, objects interested in receiving
notifications must implement the
javax.management.NotificationListener
interface. You may remember this interface from chapter 2, where you imple-
mented it in your
HelloAgent
class. Figure 6.2 shows the
UML
diagram for the
NotificationListener
interface.
Figure 6.2
UML diagram of the
NotificationListener
interface
