Package org.drools.mvel.evaluators

Class OverlapsEvaluatorDefinition

java.lang.Object
org.drools.mvel.evaluators.OverlapsEvaluatorDefinition
All Implemented Interfaces:
Externalizable, Serializable, EvaluatorDefinition, EvaluatorDefinition
public class OverlapsEvaluatorDefinition extends Object implements EvaluatorDefinition

The implementation of the overlaps evaluator definition.

The overlaps evaluator correlates two events and matches when the current event starts before the correlated event starts and finishes after the correlated event starts, but before the correlated event finishes. In other words, both events have an overlapping period.

Lets look at an example:

$eventA : EventA( this overlaps $eventB )

The previous pattern will match if and only if:

 $eventA.startTimestamp < $eventB.startTimestamp < $eventA.endTimestamp < $eventB.endTimestamp

The overlaps operator accepts 1 or 2 optional parameters as follow:

  • If one parameter is defined, this will be the maximum distance between the start timestamp of the correlated event and the end timestamp of the current event. Example:
    • $eventA : EventA( this overlaps[ 5s ] $eventB )
    Will match if and only if: 
     
 $eventA.startTimestamp < $eventB.startTimestamp < $eventA.endTimestamp < $eventB.endTimestamp &&
 0 <= $eventA.endTimestamp - $eventB.startTimestamp <= 5s
    • If two values are defined, the first value will be the minimum distance and the second value will be the maximum distance between the start timestamp of the correlated event and the end timestamp of the current event. Example:
      • $eventA : EventA( this overlaps[ 5s, 10s ] $eventB )
      Will match if and only if: 
       
 $eventA.startTimestamp < $eventB.startTimestamp < $eventA.endTimestamp < $eventB.endTimestamp &&
 5s <= $eventA.endTimestamp - $eventB.startTimestamp <= 10s
See Also: