org.apache.nifi.attribute.expression.language

Class StandardAttributeExpression

java.lang.Object

org.apache.nifi.attribute.expression.language.StandardAttributeExpression

All Implemented Interfaces:

AttributeExpression

public class StandardAttributeExpression
extends java.lang.Object
implements AttributeExpression

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.nifi.expression.AttributeExpression

AttributeExpression.ResultType

Constructor Summary

Constructors

Constructor and Description
StandardAttributeExpression(Query query)
StandardAttributeExpression(Query query, VariableRegistry variableRegistry)

Method Summary

Modifier and Type	Method and Description
java.lang.String	evaluate()
java.lang.String	evaluate(AttributeValueDecorator decorator) Evaluates the expression without additional attributes but enables the expression result to be decorated before returning.
java.lang.String	evaluate(FlowFile flowFile) Evaluates the expression providing access to additional variables including the flow file properties such as file size, identifier, etc..
java.lang.String	evaluate(FlowFile flowFile, AttributeValueDecorator decorator) Evaluates the expression providing access to additional variables including the flow file properties such as file size, identifier, etc..
AttributeExpression.ResultType	getResultType()

Methods inherited from class java.lang.Object

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

Constructor Detail

StandardAttributeExpression

public StandardAttributeExpression(Query query)

StandardAttributeExpression

public StandardAttributeExpression(Query query,
                                   VariableRegistry variableRegistry)

Method Detail

getResultType

public AttributeExpression.ResultType getResultType()

Specified by:

getResultType in interface AttributeExpression

Returns:

the type that is returned by the Expression

evaluate

public java.lang.String evaluate()
                          throws ProcessException

Specified by:

evaluate in interface AttributeExpression

Returns:

Evaluates the expression without any additional attributes.

Throws:

ProcessException - if unable to evaluate

evaluate

public java.lang.String evaluate(AttributeValueDecorator decorator)
                          throws ProcessException

Description copied from interface: AttributeExpression

Evaluates the expression without additional attributes but enables the expression result to be decorated before returning.

Specified by:

evaluate in interface AttributeExpression

Parameters:

decorator - to execute on the resulting expression value

Returns:

evaluated value

Throws:

ProcessException - if failure in evaluation

evaluate

public java.lang.String evaluate(FlowFile flowFile)
                          throws ProcessException

Description copied from interface: AttributeExpression

Evaluates the expression providing access to additional variables including the flow file properties such as file size, identifier, etc.. and also all of the flow file attributes.

Specified by:

evaluate in interface AttributeExpression

Parameters:

flowFile - to evaluate

Returns:

evaluated value

Throws:

ProcessException - if failure evaluating

evaluate

public java.lang.String evaluate(FlowFile flowFile,
                                 AttributeValueDecorator decorator)
                          throws ProcessException

Description copied from interface: AttributeExpression

Evaluates the expression providing access to additional variables including the flow file properties such as file size, identifier, etc.. and also all of the flow file attributes. The resulting value after executing any variable substitution and expression evaluation is run through the given decorator and returned.

Specified by:

evaluate in interface AttributeExpression

Parameters:

flowFile - to evaluate

decorator - for evaluation

Returns:

evaluated value

Throws:

ProcessException - if failed to evaluate