Package 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	Description
private static final String	EMPTY_STRING
private final List<Expression>	expressions
private VariableImpact	variableImpact

Constructor Summary

Constructors

Constructor	Description
StandardPreparedQuery(List<Expression> expressions)

Method Summary

Modifier and Type	Method	Description
String	evaluateExpressions(EvaluationContext evaluationContext, org.apache.nifi.expression.AttributeValueDecorator decorator)
Set<String>	getExplicitlyReferencedAttributes()	Returns a Set of all attributes that are explicitly referenced by the Prepared Query.
List<Expression>	getExpressions()
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 Details

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 Details

StandardPreparedQuery

public StandardPreparedQuery(List<Expression> expressions)

Method Details

evaluateExpressions

public String evaluateExpressions(EvaluationContext evaluationContext,
 org.apache.nifi.expression.AttributeValueDecorator decorator)
                           throws org.apache.nifi.processor.exception.ProcessException

Specified by:

evaluateExpressions in interface PreparedQuery

Throws:

org.apache.nifi.processor.exception.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.

getExpressions

public List<Expression> getExpressions()

Specified by:

getExpressions in interface PreparedQuery

Returns:

the list of all Expressions that are used to make up the Prepared Query