Package org.springframework.webflow.execution

Class Event

java.lang.Object

java.util.EventObject

org.springframework.webflow.execution.Event

All Implemented Interfaces:

Serializable

public class Event
extends EventObject

Signals the occurrence of something an active flow execution should respond to. Each event has a string id that provides a key for identifying what happened: e.g "coinInserted", or "pinDropped". Events may have attributes that provide arbitrary payload data, e.g. "coin.amount=25", or "pinDropSpeed=25ms".

As an example, a "submit" event might signal that a Submit button was pressed in a web browser. A "success" event might signal an action executed successfully. A "finish" event might signal a subflow ended normally.

Why is this not an interface? A specific design choice. An event is not a strategy that defines a generic type or role--it is essentially an immutable value object. It is expected that specializations of this base class be "Events" and not part of some other inheritance hierarchy.

Author:

Keith Donald, Erwin Vervaet, Colin Sampaleanu

See Also:

• Serialized Form

Field Summary

Fields inherited from class java.util.EventObject

source

Constructor Summary

Constructors

Constructor	Description
Event(Object source, String id)	Create a new event with the specified id and no payload.
Event(Object source, String id, AttributeMap<Object> attributes)	Create a new event with the specified id and payload attributes.

Method Summary

Modifier and Type	Method	Description
AttributeMap<Object>	getAttributes()	Returns an unmodifiable map storing the attributes of this event.
String	getId()	Returns the event identifier.
long	getTimestamp()	Returns the time at which the event occurred, represented as the number of milliseconds since January 1, 1970, 00:00:00 GMT.
String	toString()

Methods inherited from class java.util.EventObject

getSource

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

Event

public Event(Object source,
 String id)

Create a new event with the specified id and no payload.

Parameters:

source - the source of the event (required)

id - the event identifier (required)

Event

public Event(Object source,
 String id,
 AttributeMap<Object> attributes)

Create a new event with the specified id and payload attributes.

Parameters:

source - the source of the event (required)

id - the event identifier (required)

attributes - additional event attributes

Method Details

getId

public String getId()

Returns the event identifier.

Returns:

the event id

getTimestamp

public long getTimestamp()

Returns the time at which the event occurred, represented as the number of milliseconds since January 1, 1970, 00:00:00 GMT.

Returns:

the timestamp

getAttributes

public AttributeMap<Object> getAttributes()

Returns an unmodifiable map storing the attributes of this event. Never returns null.

Returns:

the event attributes (payload)

toString

public String toString()

Overrides:

toString in class EventObject