Package org.drools.mvel.evaluators

Class StartsEvaluatorDefinition

  • All Implemented Interfaces:
    java.io.Externalizable, java.io.Serializable, org.drools.compiler.rule.builder.EvaluatorDefinition, org.kie.api.runtime.rule.EvaluatorDefinition
    public class StartsEvaluatorDefinition
extends java.lang.Object
implements org.drools.compiler.rule.builder.EvaluatorDefinition

    The implementation of the starts evaluator definition.

    The starts evaluator correlates two events and matches when the current event's end timestamp happens before the correlated event's end timestamp, but both start timestamps occur at the same time.

    Lets look at an example:

    $eventA : EventA( this starts $eventB )

    The previous pattern will match if and only if the $eventA finishes before $eventB finishes and starts at the same time $eventB starts. In other words:

     
 $eventA.startTimestamp == $eventB.startTimestamp &&
 $eventA.endTimestamp < $eventB.endTimestamp

    The starts evaluator accepts one optional parameter. If it is defined, it determines the maximum distance between the start timestamp of both events in order for the operator to match. Example:

    $eventA : EventA( this starts[ 5s ] $eventB )
    Will match if and only if: 
     
 abs( $eventA.startTimestamp - $eventB.startTimestamp ) <= 5s &&
 $eventA.endTimestamp < $eventB.endTimestamp

    NOTE: it makes no sense to use a negative interval value for the parameter and the engine will raise an exception if that happens.

    See Also:
    Serialized Form

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  StartsEvaluatorDefinition.StartsEvaluator
      Implements the 'starts' evaluator itself

      • Nested classes/interfaces inherited from interface org.drools.compiler.rule.builder.EvaluatorDefinition

        org.drools.compiler.rule.builder.EvaluatorDefinition.Target

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static org.drools.drl.parser.impl.Operator STARTS  
      static org.drools.drl.parser.impl.Operator STARTS_NOT  
      protected static java.lang.String startsOp  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      org.drools.base.rule.accessor.Evaluator getEvaluator​(org.drools.base.base.ValueType type, java.lang.String operatorId, boolean isNegated, java.lang.String parameterText)  
      org.drools.base.rule.accessor.Evaluator getEvaluator​(org.drools.base.base.ValueType type, java.lang.String operatorId, boolean isNegated, java.lang.String parameterText, org.drools.compiler.rule.builder.EvaluatorDefinition.Target left, org.drools.compiler.rule.builder.EvaluatorDefinition.Target right)  
      org.drools.base.rule.accessor.Evaluator getEvaluator​(org.drools.base.base.ValueType type, org.drools.drl.parser.impl.Operator operator)  
      org.drools.base.rule.accessor.Evaluator getEvaluator​(org.drools.base.base.ValueType type, org.drools.drl.parser.impl.Operator operator, java.lang.String parameterText)  
      java.lang.String[] getEvaluatorIds()  
      org.drools.compiler.rule.builder.EvaluatorDefinition.Target getTarget()  
      boolean isNegatable()  
      void readExternal​(java.io.ObjectInput in)  
      boolean supportsType​(org.drools.base.base.ValueType type)  
      void writeExternal​(java.io.ObjectOutput out)  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • startsOp

        protected static final java.lang.String startsOp

      • STARTS

        public static final org.drools.drl.parser.impl.Operator STARTS

      • STARTS_NOT

        public static final org.drools.drl.parser.impl.Operator STARTS_NOT

    • Constructor Detail

      • StartsEvaluatorDefinition

        public StartsEvaluatorDefinition()

    • Method Detail

      • readExternal

        public void readExternal​(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException
        Specified by:
        readExternal in interface java.io.Externalizable
        Throws:
        java.io.IOException
        java.lang.ClassNotFoundException

      • writeExternal

        public void writeExternal​(java.io.ObjectOutput out)
                   throws java.io.IOException
        Specified by:
        writeExternal in interface java.io.Externalizable
        Throws:
        java.io.IOException

      • getEvaluator

        public org.drools.base.rule.accessor.Evaluator getEvaluator​(org.drools.base.base.ValueType type,
                                                            org.drools.drl.parser.impl.Operator operator)
        Specified by:
        getEvaluator in interface org.drools.compiler.rule.builder.EvaluatorDefinition

      • getEvaluator

        public org.drools.base.rule.accessor.Evaluator getEvaluator​(org.drools.base.base.ValueType type,
                                                            org.drools.drl.parser.impl.Operator operator,
                                                            java.lang.String parameterText)
        Specified by:
        getEvaluator in interface org.drools.compiler.rule.builder.EvaluatorDefinition

      • getEvaluator

        public org.drools.base.rule.accessor.Evaluator getEvaluator​(org.drools.base.base.ValueType type,
                                                            java.lang.String operatorId,
                                                            boolean isNegated,
                                                            java.lang.String parameterText)
        Specified by:
        getEvaluator in interface org.drools.compiler.rule.builder.EvaluatorDefinition

      • getEvaluator

        public org.drools.base.rule.accessor.Evaluator getEvaluator​(org.drools.base.base.ValueType type,
                                                            java.lang.String operatorId,
                                                            boolean isNegated,
                                                            java.lang.String parameterText,
                                                            org.drools.compiler.rule.builder.EvaluatorDefinition.Target left,
                                                            org.drools.compiler.rule.builder.EvaluatorDefinition.Target right)
        Specified by:
        getEvaluator in interface org.drools.compiler.rule.builder.EvaluatorDefinition

      • getEvaluatorIds

        public java.lang.String[] getEvaluatorIds()
        Specified by:
        getEvaluatorIds in interface org.drools.compiler.rule.builder.EvaluatorDefinition

      • isNegatable

        public boolean isNegatable()
        Specified by:
        isNegatable in interface org.drools.compiler.rule.builder.EvaluatorDefinition

      • getTarget

        public org.drools.compiler.rule.builder.EvaluatorDefinition.Target getTarget()
        Specified by:
        getTarget in interface org.drools.compiler.rule.builder.EvaluatorDefinition

      • supportsType

        public boolean supportsType​(org.drools.base.base.ValueType type)
        Specified by:
        supportsType in interface org.drools.compiler.rule.builder.EvaluatorDefinition