Package org.drools.mvel.evaluators

Class MetByEvaluatorDefinition

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

    The implementation of the metby evaluator definition.

    The metby evaluator correlates two events and matches when the current event's start timestamp happens at the same time as the correlated event's end timestamp.

    Lets look at an example:

    $eventA : EventA( this metby $eventB )

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

     
 abs( $eventA.startTimestamp - $eventB.endTimestamp ) == 0

    The metby evaluator accepts one optional parameter. If it is defined, it determines the maximum distance between the end timestamp of the correlated event and the start timestamp of the current event in order for the operator to match. Example:

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

    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  MetByEvaluatorDefinition.MetByEvaluator
      Implements the 'metby' 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 MET_BY  
      protected static java.lang.String metByOp  
      static org.drools.drl.parser.impl.Operator NOT_MET_BY  

    • 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

      • metByOp

        protected static final java.lang.String metByOp

      • MET_BY

        public static org.drools.drl.parser.impl.Operator MET_BY

      • NOT_MET_BY

        public static org.drools.drl.parser.impl.Operator NOT_MET_BY

    • Constructor Detail

      • MetByEvaluatorDefinition

        public MetByEvaluatorDefinition()

    • 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