org.dspace.event
Class Event

java.lang.Object
  org.dspace.event.Event

All Implemented Interfaces:

Serializable

public class Event
extends Object
implements Serializable

An Event object represents a single action that changed one object in the DSpace data model. An "atomic" action at the application or business-logic API level may spawn many of these events.

This class includes tools to help set and use the contents of the event. Note that it describes DSpace data object types in two ways: by the type identifiers in the Constants class, and also by an Event-specific bitmask (used by its internal filters). All public API calls use the Constants version of the data model types.

Note that the type of the event itself is actually descriptive of the action it performs: ADD, MODIFY, etc. The most significant elements of the event are:

• (Action) Type
• Subject -- DSpace object to which the action applies, e.g. the Collection to which an ADD adds a member.
• Object -- optional, when present it is the other object effected by an action, e.g. the Item ADDed to a Collection by an ADD.
• detail -- a textual summary of what changed. Content and its significance varies by the combination of action and subject type.
• - timestamp -- exact millisecond timestamp at which event was logged.

Version:

$Revision: 5844 $

See Also:

Serialized Form

Field Summary

static int	ADD
static int	CREATE Event (Action) types
static int	DELETE
static int	EVENT_MASK
static int	INSTALL
static int	MODIFY
static int	MODIFY_METADATA
static int	REMOVE
static int	SUBJECT_MASK Index of filter parts in their array:

Constructor Summary

Event(int eventType, int subjectType, int subjectID, int objectType, int objectID, String detail)
Constructor.

Event(int eventType, int subjectType, int subjectID, String detail)
Constructor.

Method Summary

boolean	equals(Object other) Compare two events.
BitSet	getBitSet()
int	getCurrentUser()
String	getDetail()
int	getDispatcher()
int	getEventType()
String	getEventTypeAsString() Get the text name of event (action) type.
String	getExtraLogInfo()
DSpaceObject	getObject(Context context) Get the DSpace object which is the "object" of an event.
int	getObjectID()
int	getObjectType()
String	getObjectTypeAsString()
DSpaceObject	getSubject(Context context) Syntactic sugar to get the DSpace object which is the "subject" of an event.
int	getSubjectID()
int	getSubjectType()
String	getSubjectTypeAsString()
long	getTimeStamp()
String	getTransactionID()
int	hashCode()
static int	parseEventType(String s) Interpret named event type.
static int	parseObjectType(String s) Translate a textual DSpace Object type name into an event subject-type mask.
boolean	pass(List<int[]> filters) Test whether this event would pass through a list of filters.
void	setBitSet(String consumerName) Keeps track of which consumers the event has been consumed by.
void	setCurrentUser(int uid)
void	setDispatcher(int id) Set the identifier of the dispatcher that first processed this event.
void	setExtraLogInfo(String info)
void	setTransactionID(String tid) Sets value of transactionID element of the event.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

CREATE

public static final int CREATE

Event (Action) types

See Also:

Constant Field Values

MODIFY

public static final int MODIFY

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Constant Field Values

MODIFY_METADATA

public static final int MODIFY_METADATA

See Also:

Constant Field Values

ADD

public static final int ADD

See Also:

Constant Field Values

REMOVE

public static final int REMOVE

See Also:

Constant Field Values

DELETE

public static final int DELETE

See Also:

Constant Field Values

INSTALL

public static final int INSTALL

See Also:

Constant Field Values

SUBJECT_MASK

public static final int SUBJECT_MASK

Index of filter parts in their array:

See Also:

Constant Field Values

EVENT_MASK

public static final int EVENT_MASK

See Also:

Constant Field Values

Constructor Detail

Event

public Event(int eventType,
             int subjectType,
             int subjectID,
             String detail)

Constructor.

Parameters:

eventType - action type, e.g. Event.ADD.

subjectType - DSpace Object Type of subject e.g. Constants.ITEM.

subjectID - database ID of subject instance.

detail - detail information that depends on context.

Event

public Event(int eventType,
             int subjectType,
             int subjectID,
             int objectType,
             int objectID,
             String detail)

Constructor.

Parameters:

eventType - action type, e.g. Event.ADD.

subjectType - DSpace Object Type of subject e.g. Constants.ITEM.

subjectID - database ID of subject instance.

objectType - DSpace Object Type of object e.g. Constants.BUNDLE.

objectID - database ID of object instance.

detail - detail information that depends on context.

Method Detail

equals

public boolean equals(Object other)

Compare two events. Ignore any difference in the timestamps. Also ignore transactionID since that is not always set initially.

Overrides:

equals in class Object

Parameters:

other - the event to compare this one to

Returns:

true if events are "equal", false otherwise.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

setDispatcher

public void setDispatcher(int id)

Set the identifier of the dispatcher that first processed this event.

Parameters:

id - the unique (hash code) value characteristic of the dispatcher.

getObject

public DSpaceObject getObject(Context context)
                       throws SQLException

Get the DSpace object which is the "object" of an event.

Returns:

DSpaceObject or null if none can be found or no object was set.

Throws:

SQLException

getSubject

public DSpaceObject getSubject(Context context)
                        throws SQLException

Syntactic sugar to get the DSpace object which is the "subject" of an event.

Returns:

DSpaceObject or null if none can be found.

Throws:

SQLException

getSubjectID

public int getSubjectID()

Returns:

database ID of subject of this event.

getObjectID

public int getObjectID()

Returns:

database ID of object of this event, or -1 if none was set.

getSubjectType

public int getSubjectType()

Returns:

type number (e.g. Constants.ITEM) of subject of this event.

getObjectType

public int getObjectType()

Returns:

type number (e.g. Constants.ITEM) of object of this event, or -1 if none was set.

getSubjectTypeAsString

public String getSubjectTypeAsString()

Returns:

type of subject of this event as a String, e.g. for logging.

getObjectTypeAsString

public String getObjectTypeAsString()

Returns:

type of object of this event as a String, e.g. for logging.

parseObjectType

public static int parseObjectType(String s)

Translate a textual DSpace Object type name into an event subject-type mask. NOTE: This returns a BIT-MASK, not a numeric type value; the mask is only used within the event system.

Parameters:

s - text name of object type.

Returns:

numeric value of object type or 0 for error.

getEventType

public int getEventType()

Returns:

event-type (i.e. action) this event, one of the masks like Event.ADD defined above.

getEventTypeAsString

public String getEventTypeAsString()

Get the text name of event (action) type.

Returns:

event-type (i.e. action) this event as a String, e.g. for logging.

parseEventType

public static int parseEventType(String s)

Interpret named event type.

Parameters:

s - name of event type.

Returns:

numeric value of event type or 0 for error.

getTimeStamp

public long getTimeStamp()

Returns:

timestamp at which event occurred, as a count of milliseconds since the epoch (standard Java format).

getDispatcher

public int getDispatcher()

Returns:

hashcode identifier of name of Dispatcher which first dispatched this event. (Needed by asynch dispatch code.)

getDetail

public String getDetail()

Returns:

value of detail element of the event.

getTransactionID

public String getTransactionID()

Returns:

value of transactionID element of the event.

setTransactionID

public void setTransactionID(String tid)

Sets value of transactionID element of the event.

Parameters:

tid - new value of transactionID.

setCurrentUser

public void setCurrentUser(int uid)

getCurrentUser

public int getCurrentUser()

setExtraLogInfo

public void setExtraLogInfo(String info)

getExtraLogInfo

public String getExtraLogInfo()

pass

public boolean pass(List<int[]> filters)

Test whether this event would pass through a list of filters.

Parameters:

filters - list of filter masks; each one is an Array of two ints.

Returns:

true if this event would be passed through the given filter list.

setBitSet

public void setBitSet(String consumerName)

Keeps track of which consumers the event has been consumed by. Should be called by a dispatcher when calling consume(Context ctx, String name, Event event) on an event.

Parameters:

consumerName -

getBitSet

public BitSet getBitSet()

Returns:

the set of consumers which have consumed this Event.

toString

public String toString()

Overrides:

toString in class Object

Returns:

Detailed string representation of contents of this event, to help in logging and debugging.