cascading.operation.aggregator
Class Last

java.lang.Object
  cascading.operation.BaseOperation<Tuple[]>
      cascading.operation.aggregator.ExtentBase
          cascading.operation.aggregator.Last

All Implemented Interfaces:

DeclaresResults, Aggregator<Tuple[]>, Operation<Tuple[]>, Traceable, Serializable

public class Last
extends ExtentBase

Class Last is an Aggregator that returns the last Tuple encountered.

By default, it returns the last Tuple of Fields.ARGS found.

See Also:

Serialized Form

Field Summary

Fields inherited from class cascading.operation.BaseOperation

fieldDeclaration, numArgs, trace

Fields inherited from interface cascading.operation.Operation

ANY

Constructor Summary

Last()
Selects and returns the last argument Tuple encountered.

Last(Fields fieldDeclaration)
Selects and returns the last argument Tuple encountered.

Last(Fields fieldDeclaration, Tuple... ignoreTuples)
Selects and returns the last argument Tuple encountered, unless the Tuple is a member of the set ignoreTuples.

Method Summary

protected void

performOperation(Tuple[] context, TupleEntry entry)

Methods inherited from class cascading.operation.aggregator.ExtentBase

aggregate, complete, equals, getIgnoreTuples, getResult, hashCode, prepare, start

Methods inherited from class cascading.operation.BaseOperation

cleanup, flush, getFieldDeclaration, getNumArgs, getTrace, isSafe, printOperationInternal, toString, toStringInternal

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface cascading.operation.Operation

cleanup, flush, getFieldDeclaration, getNumArgs, isSafe

Constructor Detail

Last

public Last()

Selects and returns the last argument Tuple encountered.

Last

@ConstructorProperties(value="fieldDeclaration")
public Last(Fields fieldDeclaration)

Selects and returns the last argument Tuple encountered.

Parameters:

fieldDeclaration - of type Fields

Last

@ConstructorProperties(value={"fieldDeclaration","ignoreTuples"})
public Last(Fields fieldDeclaration,
                                       Tuple... ignoreTuples)

Selects and returns the last argument Tuple encountered, unless the Tuple is a member of the set ignoreTuples.

Parameters:

fieldDeclaration - of type Fields

ignoreTuples - of type Tuple...

Method Detail

performOperation

protected void performOperation(Tuple[] context,
                                TupleEntry entry)

Specified by:

performOperation in class ExtentBase