cascading.operation.aggregator
Class Last

java.lang.Object
  extended by cascading.operation.BaseOperation<Tuple[]>
      extended by cascading.operation.aggregator.ExtentBase
          extended by cascading.operation.aggregator.Last
All Implemented Interfaces:
Aggregator<Tuple[]>, Operation<Tuple[]>, 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


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