# Class JMXConnectionNotification

java.lang.Object
java.util.EventObject
javax.management.Notification
javax.management.remote.JMXConnectionNotification

All Implemented Interfaces:
  `Serializable`

public class JMXConnectionNotification extends Notification

Notification emitted when a client connection is opened or closed or when notifications are lost. These notifications are sent by connector servers (instances of `JMXConnectorServer`) and by connector clients (instances of `JMXConnector`). For certain connectors, a session can consist of a sequence of connections. Connection-opened and connection-closed notifications will be sent for each one.

The notification type is one of the following:

JMXConnectionNotification Types
Type | Meaning
--- | ---
`jmx.remote.connection.opened` | A new client connection has been opened.
`jmx.remote.connection.closed` | A client connection has been closed.
`jmx.remote.connection.failed` | A client connection has failed unexpectedly.
`jmx.remote.connection.notifs.lost` | A client connection has potentially lost notifications. This notification only appears on the client side.

The `timeStamp` of the notification is a time value (consistent with `System.currentTimeMillis()`) indicating when the notification was constructed.

Since:
  1.5
See Also:
  - Serialized Form

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final String`
  `CLOSED`
  Notification type string for a connection-closed notification.
  `static final String`
  `FAILED`
  Notification type string for a connection-failed notification.
  `static final String`
  `NOTIFS_LOST`
  Notification type string for a connection that has possibly lost notifications.
  `static final String`
  `OPENED`
  Notification type string for a connection-opened notification.

  ### Fields declared in class javax.management.Notification

  `source`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `JMXConnectionNotification(String type, Object source, String connectionId, long sequenceNumber, String message, Object userData)`
  Constructs a new connection notification.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `String`
  `getConnectionId()`
  The connection ID to which this notification pertains.

  ### Methods declared in class javax.management.Notification

  `getMessage, getSequenceNumber, getTimeStamp, getType, getUserData, setSequenceNumber, setSource, setTimeStamp, setUserData, toString`

  ### Methods declared in class java.util.EventObject

  `getSource`

  ### Methods declared in class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- ## Field Details

  - ### OPENED

    public static final String OPENED

    Notification type string for a connection-opened notification.

    See Also:
      - Constant Field Values

  - ### CLOSED

    public static final String CLOSED

    Notification type string for a connection-closed notification.

    See Also:
      - Constant Field Values

  - ### FAILED

    public static final String FAILED

    Notification type string for a connection-failed notification.

    See Also:
      - Constant Field Values

  - ### NOTIFS_LOST

    public static final String NOTIFS_LOST

    Notification type string for a connection that has possibly lost notifications.

    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### JMXConnectionNotification

    public JMXConnectionNotification(String type, Object source, String connectionId, long sequenceNumber, String message, Object userData)
    Constructs a new connection notification. The `source` of the notification depends on whether it is being sent by a connector server or a connector client:
    - For a connector server, if it is registered in an MBean server, the source is the `ObjectName` under which it is registered. Otherwise, it is a reference to the connector server object itself, an instance of a subclass of `JMXConnectorServer`.
    - For a connector client, the source is a reference to the connector client object, an instance of a class implementing `JMXConnector`.
    Parameters:
      `type` - the type of the notification. This is usually one of the constants `OPENED`, `CLOSED`, `FAILED`, `NOTIFS_LOST`. It is not an error for it to be a different string.
      `source` - the connector server or client emitting the notification.
      `connectionId` - the ID of the connection within its connector server.
      `sequenceNumber` - a non-negative integer. It is expected but not required that this number will be greater than any previous `sequenceNumber` in a notification from this source.
      `message` - an unspecified text message, typically containing a human-readable description of the event. Can be null.
      `userData` - an object whose type and meaning is defined by the connector server. Can be null.
    Throws:
      `NullPointerException` - if `type`, `source`, or `connectionId` is null.
      `IllegalArgumentException` - if `sequenceNumber` is negative.

- ## Method Details

  - ### getConnectionId

    public String getConnectionId()

    The connection ID to which this notification pertains.

    Returns:
      the connection ID.