org.apache.nifi.attribute.expression.language

Class StandardPreparedQuery

java.lang.Object

org.apache.nifi.attribute.expression.language.StandardPreparedQuery

All Implemented Interfaces:

PreparedQuery

public class StandardPreparedQuery
extends Object
implements PreparedQuery

Field Summary

Fields

Modifier and Type	Field and Description
private static String	EMPTY_STRING
private List<Expression>	expressions
private VariableImpact	variableImpact

Constructor Summary

Constructors

Constructor and Description
StandardPreparedQuery(List<Expression> expressions)

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()

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_STRING

private static final String EMPTY_STRING

See Also:

Constant Field Values

expressions

private final List<Expression> expressions

variableImpact

private volatile VariableImpact variableImpact

Constructor Detail

StandardPreparedQuery

public StandardPreparedQuery(List<Expression> expressions)

Method Detail

evaluateExpressions

public String evaluateExpressions(EvaluationContext evaluationContext,
                                  AttributeValueDecorator decorator)
                           throws ProcessException

Specified by:

evaluateExpressions in interface PreparedQuery

Throws:

ProcessException

isExpressionLanguagePresent

public boolean isExpressionLanguagePresent()

Specified by:

isExpressionLanguagePresent in interface PreparedQuery

getExplicitlyReferencedAttributes

public Set<String> getExplicitlyReferencedAttributes()

Description copied from interface: PreparedQuery

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.

Specified by:

getExplicitlyReferencedAttributes in interface PreparedQuery

Returns:

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

getVariableImpact

public VariableImpact getVariableImpact()

Description copied from interface: PreparedQuery

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

Specified by:

getVariableImpact in interface PreparedQuery

Returns:

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