org.osgi.service.dmt

Interface DmtEvent

public interface DmtEvent

Event class storing the details of a change in the tree. DmtEvent is used by DmtAdmin to notify registered EventListeners services about important changes. Events are generated after every successful DMT change, and also when sessions are opened or closed. If a DmtSession is opened in atomic mode, DMT events are only sent when the session is committed, when the changes are actually performed.

The type of the event describes the change that triggered the event delivery. Each event carries the unique identifier of the session in which the described change happened or -1 when the change originated outside a session. The events describing changes in the DMT carry the list of affected nodes. In case of COPIED or RENAMED events, the event carries the list of new nodes as well.

Field Summary

Fields

Modifier and Type	Field and Description
static int	ADDED Event type indicating nodes that were added.
static int	COPIED Event type indicating nodes that were copied.
static int	DELETED Event type indicating nodes that were deleted.
static int	RENAMED Event type indicating nodes that were renamed.
static int	REPLACED Event type indicating nodes that were replaced.
static int	SESSION_CLOSED Event type indicating that a session was closed.
static int	SESSION_OPENED Event type indicating that a new session was opened.

Method Summary

Methods

Modifier and Type	Method and Description
String[]	getNewNodes() This method can be used to query the new nodes, when the type of the event is COPIED or RENAMED.
String[]	getNodes() This method can be used to query the subject nodes of this event.
Object	getProperty(String key) This method can be used to get the value of a single event property.
String[]	getPropertyNames() This method can be used to query the names of all properties of this event.
int	getSessionId() This method returns the identifier of the session in which this event took place.
int	getType() This method returns the type of this event.

Field Detail

ADDED

static final int ADDED

Event type indicating nodes that were added.

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Constant Field Values

COPIED

static final int COPIED

Event type indicating nodes that were copied.

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Constant Field Values

DELETED

static final int DELETED

Event type indicating nodes that were deleted.

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Constant Field Values

RENAMED

static final int RENAMED

Event type indicating nodes that were renamed.

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Constant Field Values

REPLACED

static final int REPLACED

Event type indicating nodes that were replaced.

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Constant Field Values

SESSION_OPENED

static final int SESSION_OPENED

Event type indicating that a new session was opened.

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Constant Field Values

SESSION_CLOSED

static final int SESSION_CLOSED

Event type indicating that a session was closed. This type of event is sent when the session is closed by the client or becomes inactive for any other reason (session timeout, fatal errors in business methods, etc.).

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Constant Field Values

Method Detail

getType

int getType()

This method returns the type of this event.

Returns:

the type of this event.

getSessionId

int getSessionId()

This method returns the identifier of the session in which this event took place. The ID is guaranteed to be unique on a machine.

For events that do not result from a session, the session id is -1.

The availability of a session.id can also be check by using getProperty() with "session.id" as key.

Returns:

the unique identifier of the session that triggered the event or -1 if there is no session associated

getNodes

String[] getNodes()

This method can be used to query the subject nodes of this event. The method returns null for SESSION_OPENED and SESSION_CLOSED.

The method returns only those affected nodes that the caller has the GET permission for (or in case of COPIED or RENAMED events, where the caller has GET permissions for either the source or the destination nodes). Therefore, it is possible that the method returns an empty array. All returned URIs are absolute.

Returns:

the array of affected nodes

See Also:

getNewNodes()

getNewNodes

String[] getNewNodes()

This method can be used to query the new nodes, when the type of the event is COPIED or RENAMED. For all other event types this method returns null.

The array returned by this method runs parallel to the array returned by getNodes(), the elements in the two arrays contain the source and destination URIs for the renamed or copied nodes in the same order. All returned URIs are absolute.

This method returns only those nodes where the caller has the GET permission for the source or destination node of the operation. Therefore, it is possible that the method returns an empty array.

Returns:

the array of newly created nodes

getPropertyNames

String[] getPropertyNames()

This method can be used to query the names of all properties of this event.

The returned names can be used as key value in subsequent calls to getProperty(String).

Returns:

the array of property names

Since:

2.0

See Also:

getProperty(String)

getProperty

Object getProperty(String key)

This method can be used to get the value of a single event property.

Parameters:

key - the name of the requested property

Returns:

the requested property value or null, if the key is not contained in the properties

Since:

2.0

See Also:

getPropertyNames()