cascading.operation.aggregator
Class Last

java.lang.Object
  cascading.operation.BaseOperation
      cascading.operation.aggregator.ExtentBase
          cascading.operation.aggregator.Last

All Implemented Interfaces:

Aggregator, Operation, 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

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(Map context, TupleEntry entry)

Methods inherited from class cascading.operation.aggregator.ExtentBase

aggregate, complete, start

Methods inherited from class cascading.operation.BaseOperation

getFieldDeclaration, getNumArgs, printOperationInternal, toString, toStringInternal

Methods inherited from class java.lang.Object

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

Methods inherited from interface cascading.operation.Operation

getFieldDeclaration, getNumArgs

Constructor Detail

Last

public Last()

Selects and returns the last argument Tuple encountered.

Last

public Last(Fields fieldDeclaration)

Selects and returns the last argument Tuple encountered.

Parameters:

fieldDeclaration - of type Fields

Last

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(Map context,
                                TupleEntry entry)

Specified by:

performOperation in class ExtentBase