org.apache.nifi.attribute.expression.language

Interface PreparedQuery

All Known Implementing Classes:

EmptyPreparedQuery, InvalidPreparedQuery, StandardPreparedQuery

public interface PreparedQuery

Method Summary

Modifier and Type	Method and Description
String	evaluateExpressions(EvaluationContext evaluationContext, AttributeValueDecorator decorator)
Set<String>	getExplicitlyReferencedAttributes() Returns a Set of all attributes that are explicitly referenced by the Prepared Query.
VariableImpact	getVariableImpact() Returns a VariableImpact that can be used to determine whether or not a given variable impacts this Expression.
boolean	isExpressionLanguagePresent()

Method Detail

evaluateExpressions

String evaluateExpressions(EvaluationContext evaluationContext,
                           AttributeValueDecorator decorator)
                    throws ProcessException

Throws:

ProcessException

isExpressionLanguagePresent

boolean isExpressionLanguagePresent()

getVariableImpact

VariableImpact getVariableImpact()

Returns a VariableImpact that can be used to determine whether or not a given variable impacts this Expression.

Returns:

a VariableImpact that can be used to determine whether or not a given variable impacts this Expression.

getExplicitlyReferencedAttributes

Set<String> getExplicitlyReferencedAttributes()

Returns a Set of all attributes that are explicitly referenced by the Prepared Query. There are some expressions, however, such as ${allMatchingAttributes('a.*'):gt(4)} that reference multiple attributes, but those attributes' names cannot be determined a priori. As a result, those attributes will not be included in the returned set.

Returns:

a Set of all attributes that are explicitly referenced by the Prepared Query