org.apache.nifi.expression

Interface AttributeExpression

public interface AttributeExpression

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	AttributeExpression.ResultType

Method Summary

Modifier and Type	Method and Description
String	evaluate()
String	evaluate(AttributeValueDecorator decorator) Evaluates the expression without providing any FlowFile Attributes.
String	evaluate(FlowFile flowFile) Evaluates the expression, providing access to the attributes, file size, id, etc.
String	evaluate(FlowFile flowFile, AttributeValueDecorator decorator) Evaluates the expression, providing access to the attributes, file size, id, etc.
AttributeExpression.ResultType	getResultType()

Method Detail

evaluate

String evaluate()
         throws ProcessException

Returns:

Evaluates the expression without providing any FlowFile Attributes. This will evaluate the expression based only on System Properties and JVM Environment properties

Throws:

ProcessException - if unable to evaluate

evaluate

String evaluate(AttributeValueDecorator decorator)
         throws ProcessException

Evaluates the expression without providing any FlowFile Attributes. This will evaluate the expression based only on System Properties and JVM Environment properties but allows the values to be decorated

Parameters:

decorator - for attribute value

Returns:

evaluated value

Throws:

ProcessException - if failure in evaluation

evaluate

String evaluate(FlowFile flowFile)
         throws ProcessException

Evaluates the expression, providing access to the attributes, file size, id, etc. of the given FlowFile, as well as System Properties and JVM Environment properties

Parameters:

flowFile - to evaluate

Returns:

evaluated value

Throws:

ProcessException - if failure evaluating

evaluate

String evaluate(FlowFile flowFile,
                AttributeValueDecorator decorator)
         throws ProcessException

Evaluates the expression, providing access to the attributes, file size, id, etc. of the given FlowFile, as well as System Properties and JVM Environment properties and allows the values to be decorated

Parameters:

flowFile - to evaluate

decorator - for evaluation

Returns:

evaluated value

Throws:

ProcessException - if failed to evaluate

getResultType

AttributeExpression.ResultType getResultType()

Returns:

the type that is returned by the Expression