com.apama.jmon
Class EventExpression

java.lang.Object
  com.apama.jmon.EventExpression

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

PreparedEventExpression

public class EventExpression
extends java.lang.Object
implements java.io.Serializable

Instances of this class are declared to represent an "Event Expression" as defined in the Apama reference manual "The JMON Application Framework".

An example expression is:

    NewsItem("ACME", *):news -> StockTick("ACME", *)
 

In this example the matching NewsItem event is tagged as 'news'. This means that the NewsItem event that caused the match will be available to the MatchListener from the fired MatchEvent by calling evt.getMatchingEvent("news");

When the expression is matched, all registered listeners will be informed. An object implementing the MatchListener interface may be registered by calling the addMatchListener method, and deregistered by calling the removeMatchListener method.

See Also:

Serialized Form

Constructor Summary

EventExpression(java.lang.String eventExpressionString)
Constructor to create a new instance with the given immutable expression string.

Method Summary

void	addMatchListener(MatchListener listenerToAdd) Add a listener to be notified when the match occurs for this event expression.
java.lang.String	getEventExpressionString() Get the String value of the EventExpression.
void	removeAllMatchListeners() Remove all previously registered match listeners.
void	removeMatchListener(MatchListener listenerToRemove) Remove a match listener that was previously registered.
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

EventExpression

public EventExpression(java.lang.String eventExpressionString)

Constructor to create a new instance with the given immutable expression string.

Parameters:

eventExpressionString - The event expression to be used.

Method Detail

getEventExpressionString

public java.lang.String getEventExpressionString()

Get the String value of the EventExpression.

Returns:

value of the EventExpression

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

getEventExpressionString()

addMatchListener

public void addMatchListener(MatchListener listenerToAdd)

Add a listener to be notified when the match occurs for this event expression.

Parameters:

listenerToAdd - an object implementing the MatchListener interface to be notified when matches occur for this expression.

removeMatchListener

public void removeMatchListener(MatchListener listenerToRemove)

Remove a match listener that was previously registered.

Parameters:

listenerToRemove - an object implementing the MatchListener interface to be removed from the notification list for this expression.

removeAllMatchListeners

public void removeAllMatchListeners()

Remove all previously registered match listeners.