Module java.management

Package javax.management.remote

Interface JMXConnector

All Superinterfaces:

AutoCloseable, Closeable

All Known Implementing Classes:

RMIConnector

public interface JMXConnector
extends Closeable

The client end of a JMX API connector. An object of this type can be used to establish a connection to a connector server.

A newly-created object of this type is unconnected. Its connect method must be called before it can be used. However, objects created by JMXConnectorFactory.connect are already connected.

Since:

1.5

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CREDENTIALS	Name of the attribute that specifies the credentials to send to the connector server during connection.

Method Summary

Modifier and Type	Method	Description
void	addConnectionNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback)	Adds a listener to be informed of changes in connection status.
void	close()	Closes the client connection to its server.
void	connect()	Establishes the connection to the connector server.
void	connect(Map<String,?> env)	Establishes the connection to the connector server.
String	getConnectionId()	Gets this connection's ID from the connector server.
MBeanServerConnection	getMBeanServerConnection()	Returns an MBeanServerConnection object representing a remote MBean server.
MBeanServerConnection	getMBeanServerConnection(Subject delegationSubject)	Deprecated, for removal: This API element is subject to removal in a future version. This method supported the legacy Subject Delegation feature, and is only useful in conjunction with other APIs which are deprecated and subject to removal in a future release.
void	removeConnectionNotificationListener(NotificationListener listener)	Removes a listener from the list to be informed of changes in status.
void	removeConnectionNotificationListener(NotificationListener l, NotificationFilter f, Object handback)	Removes a listener from the list to be informed of changes in status.

Field Details

CREDENTIALS

static final String CREDENTIALS

Name of the attribute that specifies the credentials to send to the connector server during connection. The value associated with this attribute, if any, is a serializable object of an appropriate type for the server's JMXAuthenticator.

See Also:

• Constant Field Values

Method Details

connect

void connect()
      throws IOException

Establishes the connection to the connector server. This method is equivalent to connect(null).

Throws:

IOException - if the connection could not be made because of a communication problem.

SecurityException - if the connection could not be made for security reasons.

connect

void connect(Map<String,?> env)
      throws IOException

Establishes the connection to the connector server.

If connect has already been called successfully on this object, calling it again has no effect. If, however, close() was called after connect, the new connect will throw an IOException.

Otherwise, either connect has never been called on this object, or it has been called but produced an exception. Then calling connect will attempt to establish a connection to the connector server.

Parameters:

env - the properties of the connection. Properties in this map override properties in the map specified when the JMXConnector was created, if any. This parameter can be null, which is equivalent to an empty map.

Throws:

IOException - if the connection could not be made because of a communication problem.

SecurityException - if the connection could not be made for security reasons.

getMBeanServerConnection

MBeanServerConnection getMBeanServerConnection()
                                        throws IOException

Returns an MBeanServerConnection object representing a remote MBean server. For a given JMXConnector, two successful calls to this method will usually return the same MBeanServerConnection object, though this is not required.

For each method in the returned MBeanServerConnection, calling the method causes the corresponding method to be called in the remote MBean server. The value returned by the MBean server method is the value returned to the client. If the MBean server method produces an Exception, the same Exception is seen by the client. If the MBean server method, or the attempt to call it, produces an Error, the Error is wrapped in a JMXServerErrorException, which is seen by the client.

Calling this method is equivalent to calling getMBeanServerConnection(null) meaning that no delegation subject is specified and that all the operations called on the MBeanServerConnection must use the authenticated subject, if any.

Returns:

an object that implements the MBeanServerConnection interface by forwarding its methods to the remote MBean server.

Throws:

IOException - if a valid MBeanServerConnection cannot be created, for instance because the connection to the remote MBean server has not yet been established (with the connect method), or it has been closed, or it has broken.

getMBeanServerConnection

@Deprecated(since="21",
            forRemoval=true)
MBeanServerConnection getMBeanServerConnection(Subject delegationSubject)
                                        throws IOException

Deprecated, for removal: This API element is subject to removal in a future version.

This method supported the legacy Subject Delegation feature, and is only useful in conjunction with other APIs which are deprecated and subject to removal in a future release. Consequently, this method is also deprecated and subject to removal. There is no replacement.

Returns an MBeanServerConnection object representing a remote MBean server on which operations are performed on behalf of the supplied delegation subject. For a given JMXConnector and Subject, two successful calls to this method will usually return the same MBeanServerConnection object, though this is not required.

For each method in the returned MBeanServerConnection, calling the method causes the corresponding method to be called in the remote MBean server on behalf of the given delegation subject instead of the authenticated subject. The value returned by the MBean server method is the value returned to the client. If the MBean server method produces an Exception, the same Exception is seen by the client. If the MBean server method, or the attempt to call it, produces an Error, the Error is wrapped in a JMXServerErrorException, which is seen by the client.

Parameters:

delegationSubject - the Subject on behalf of which requests will be performed. Can be null, in which case requests will be performed on behalf of the authenticated Subject, if any.

Returns:

an object that implements the MBeanServerConnection interface by forwarding its methods to the remote MBean server on behalf of a given delegation subject.

Throws:

IOException - if a valid MBeanServerConnection cannot be created, for instance because the connection to the remote MBean server has not yet been established (with the connect method), or it has been closed, or it has broken.

close

void close()
    throws IOException

Closes the client connection to its server. Any ongoing or new request using the MBeanServerConnection returned by getMBeanServerConnection() will get an IOException.

If close has already been called successfully on this object, calling it again has no effect. If close has never been called, or if it was called but produced an exception, an attempt will be made to close the connection. This attempt can succeed, in which case close will return normally, or it can generate an exception.

Closing a connection is a potentially slow operation. For example, if the server has crashed, the close operation might have to wait for a network protocol timeout. Callers that do not want to block in a close operation should do it in a separate thread.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException - if the connection cannot be closed cleanly. If this exception is thrown, it is not known whether the server end of the connection has been cleanly closed.

addConnectionNotificationListener

void addConnectionNotificationListener(NotificationListener listener,
 NotificationFilter filter,
 Object handback)

Adds a listener to be informed of changes in connection status. The listener will receive notifications of type JMXConnectionNotification. An implementation can send other types of notifications too.

Any number of listeners can be added with this method. The same listener can be added more than once with the same or different values for the filter and handback. There is no special treatment of a duplicate entry. For example, if a listener is registered twice with no filter, then its handleNotification method will be called twice for each notification.

Parameters:

listener - a listener to receive connection status notifications.

filter - a filter to select which notifications are to be delivered to the listener, or null if all notifications are to be delivered.

handback - an object to be given to the listener along with each notification. Can be null.

Throws:

NullPointerException - if listener is null.

See Also:

• removeConnectionNotificationListener(javax.management.NotificationListener)
• NotificationBroadcaster.addNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)

removeConnectionNotificationListener

void removeConnectionNotificationListener(NotificationListener listener)
                                   throws ListenerNotFoundException

Removes a listener from the list to be informed of changes in status. The listener must previously have been added. If there is more than one matching listener, all are removed.

Parameters:

listener - a listener to receive connection status notifications.

Throws:

NullPointerException - if listener is null.

ListenerNotFoundException - if the listener is not registered with this JMXConnector.

See Also:

• removeConnectionNotificationListener(NotificationListener, NotificationFilter, Object)
• addConnectionNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)
• NotificationEmitter.removeNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)

removeConnectionNotificationListener

void removeConnectionNotificationListener(NotificationListener l,
 NotificationFilter f,
 Object handback)
                                   throws ListenerNotFoundException

Removes a listener from the list to be informed of changes in status. The listener must previously have been added with the same three parameters. If there is more than one matching listener, only one is removed.

Parameters:

l - a listener to receive connection status notifications.

f - a filter to select which notifications are to be delivered to the listener. Can be null.

handback - an object to be given to the listener along with each notification. Can be null.

Throws:

ListenerNotFoundException - if the listener is not registered with this JMXConnector, or is not registered with the given filter and handback.

See Also:

• removeConnectionNotificationListener(NotificationListener)
• addConnectionNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)
• NotificationEmitter.removeNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)

getConnectionId

String getConnectionId()
                throws IOException

Gets this connection's ID from the connector server. For a given connector server, every connection will have a unique id which does not change during the lifetime of the connection.

Returns:

the unique ID of this connection. This is the same as the ID that the connector server includes in its JMXConnectionNotifications. The package description describes the conventions for connection IDs.

Throws:

IOException - if the connection ID cannot be obtained, for instance because the connection is closed or broken.