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 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

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      java.lang.String[] getNewNodes()
      This method can be used to query the new nodes, when the type of the event is COPIED or RENAMED.
      java.lang.String[] getNodes()
      This method can be used to query the subject nodes of this event.
      java.lang.Object getProperty​(java.lang.String key)
      This method can be used to get the value of a single event property.
      java.lang.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.
        See Also:
        Constant Field Values
      • COPIED

        static final int COPIED
        Event type indicating nodes that were copied.
        See Also:
        Constant Field Values
      • DELETED

        static final int DELETED
        Event type indicating nodes that were deleted.
        See Also:
        Constant Field Values
      • RENAMED

        static final int RENAMED
        Event type indicating nodes that were renamed.
        See Also:
        Constant Field Values
      • REPLACED

        static final int REPLACED
        Event type indicating nodes that were replaced.
        See Also:
        Constant Field Values
      • SESSION_OPENED

        static final int SESSION_OPENED
        Event type indicating that a new session was opened.
        See Also:
        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.).
        See Also:
        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

        java.lang.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

        java.lang.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

        java.lang.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

        java.lang.Object getProperty​(java.lang.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()