Package org.imixs.workflow.engine

Class EventLogService

  • @DeclareRoles({"org.imixs.ACCESSLEVEL.NOACCESS","org.imixs.ACCESSLEVEL.READERACCESS","org.imixs.ACCESSLEVEL.AUTHORACCESS","org.imixs.ACCESSLEVEL.EDITORACCESS","org.imixs.ACCESSLEVEL.MANAGERACCESS"})
@RolesAllowed({"org.imixs.ACCESSLEVEL.NOACCESS","org.imixs.ACCESSLEVEL.READERACCESS","org.imixs.ACCESSLEVEL.AUTHORACCESS","org.imixs.ACCESSLEVEL.EDITORACCESS","org.imixs.ACCESSLEVEL.MANAGERACCESS"})
public class EventLogService
extends Object
    The EventLogService is a service to create and access an event log .

    An event that occurs during an update or a processing function within a transaction becomes a fact when the transaction completes successfully. The EventLogService can be used to store this kind of "Change Data Capture" events in a log. An example is the LuceneUpdateService, which should update the index of a document only if the document was successfully written to the database.

    The service is bound to the current PersistenceContext and stores a EventLog entity directly in the database to represent an event. These types of events can be queried by clients through the service.

    The EventLogService provides a lock/unlock mechanism. An eventLog entry can optional be locked for processing. The topic of the event will be suffixed with '.lock' to indicate that this topic is locked by a running process. If a lock is successful a client can exclusive process this eventLog entry.

    The method releaseDeadLocks unlocks eventlog entries which are older than 1 minute. We assume that these events are deadlocks.

    Version:
    1.0
    Author:
    rsoika
    See Also:
    EventLog, UpdateService

    • Constructor Detail

      • EventLogService

        public EventLogService()

    • Method Detail

      • createEvent

        public EventLog createEvent​(String topic,
                            String refID)
        Creates/updates a new event log entry.
        Parameters:
        refID - - uniqueid of the document to be assigned to the event
        topic - - the topic of the event.
        Returns:
        - generated event log entry

      • createEvent

        public EventLog createEvent​(String topic,
                            String refID,
                            Calendar timeout)
        Creates/updates a new event log entry.
        Parameters:
        refID - - uniqueid of the document to be assigned to the event
        topic - - the topic of the event.
        timeout - - optional timeout calendar object
        Returns:
        - generated event log entry

      • createEvent

        public EventLog createEvent​(String topic,
                            String refID,
                            ItemCollection document)
        Creates/updates a new event log entry.
        Parameters:
        refID - - uniqueId of the document to be assigned to the event
        topic - - the topic of the event.
        document - - optional document providing a data map
        Returns:
        - generated event log entry

      • createEvent

        public EventLog createEvent​(String topic,
                            String refID,
                            ItemCollection document,
                            Calendar timeout)
        Creates/updates a new event log entry.
        Parameters:
        refID - - uniqueId of the document to be assigned to the event
        topic - - the topic of the event.
        document - - optional document providing a data map
        timeout - - optional timeout calendar object
        Returns:
        - generated event log entry

      • createEvent

        public EventLog createEvent​(String topic,
                            String refID,
                            Map<String,​List<Object>> data,
                            Calendar timeout)
        Creates/updates a new event log entry.
        Parameters:
        refID - - uniqueId of the document to be assigned to the event
        topic - - the topic of the event.
        data - - optional data map
        Returns:
        - generated event log entry

      • findEventsByTopic

        public List<EventLog> findEventsByTopic​(int maxCount,
                                        String... topic)
        Finds events for one or many given topics
        Parameters:
        maxCount - - maximum count of events to be returned
        topic - - list of topics
        Returns:
        - list of eventLogEntries

      • findEventsByTimeout

        public List<EventLog> findEventsByTimeout​(int maxCount,
                                          String... topic)
        Finds events for one or many given topics within the current timeout.

        The attribute 'timeout' is optional. If the timeout is set to a future point of time, the event will be ignored by this method.

        Parameters:
        maxCount - - maximum count of events to be returned
        topic - - list of topics
        Returns:
        - list of eventLogEntries

      • findEventsByRef

        public List<EventLog> findEventsByRef​(int maxCount,
                                      String ref,
                                      String... topic)
        Finds events for one or many given topics assigned to a given document reference ($uniqueId). The method returns an empty list if no event log entries exist of the given refId,
        Parameters:
        maxCount - - maximum count of events to be returned
        ref - - a reference ID for an assigned Document or Workitem instance
        topic - - list of topics
        Returns:
        - list of eventLogEntries

      • findAllEvents

        public List<EventLog> findAllEvents​(int firstResult,
                                    int maxResult)
        Returns all event log entries
        Parameters:
        firstResult - - first result
        maxResult - - maximum count of events to be returned
        Returns:
        - list of eventLogEntries

      • removeEvent

        public void removeEvent​(EventLog _eventLog)
        Deletes an existing eventLog. The method catches jakarta.persistence.OptimisticLockException as this may occur during parallel requests.
        Parameters:
        eventLog -

      • removeEvent

        public void removeEvent​(String id)
        Deletes an existing eventLog by its id. The method catches jakarta.persistence.OptimisticLockException as this may occur during parallel requests.
        Parameters:
        eventLog -

      • getEvent

        public EventLog getEvent​(String id)
        Returns an detached event log entry by its ID.
        Parameters:
        id - - id of the eventLog Entry
        Returns:
        detached eventLog entry or null if not found

      • lock

        public boolean lock​(EventLog _eventLogEntry)
        This method locks an eventLog entry for processing. The topic will be suffixed with '.lock' to indicate that this topic is locked by a process. If a lock is successful a client can exclusive process this eventLog entry.

        The method adds a item 'eventlog.lock.date' with a timestamp. This timestamp is used by the method 'autoUnlock' to release locked entries.

        Parameters:
        eventLogEntry -
        Returns:
        - true if lock was successful

      • unlock

        public boolean unlock​(EventLog _eventLogEntry)
        This method unlocks an eventLog entry. The topic suffix '.lock' will be removed.
        Parameters:
        eventLogEntry -
        Returns:
        - true if unlock was successful

      • releaseDeadLocks

        public void releaseDeadLocks​(long deadLockInterval,
                             String... topic)
        This method unlocks eventlog entries which are older than 1 minute. We assume that these events are deadlocks.