cascading.nested.core.aggregate

Class SimpleNestedAggregate<Node>

java.lang.Object

cascading.nested.core.aggregate.SimpleNestedAggregate<Node>

Type Parameters:

Node -

All Implemented Interfaces:

NestedAggregate<Node,SimpleNestedAggregate.AggregateContext<Node>>, java.io.Serializable

public class SimpleNestedAggregate<Node>
extends java.lang.Object
implements NestedAggregate<Node,SimpleNestedAggregate.AggregateContext<Node>>

Class SimpleNestedAggregate provides a simple extensible implementation of NestedAggregate.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	SimpleNestedAggregate.AggregateContext<Node>

Field Summary

Fields

Modifier and Type	Field and Description
protected cascading.operation.SerFunction<cascading.tuple.type.CoercibleType<Node>,SimpleNestedAggregate.AggregateContext<Node>>	factory
protected cascading.tuple.Fields	fieldDeclaration

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleNestedAggregate() Create a new instance of SimpleNestedAggregate without a factory
protected	SimpleNestedAggregate(cascading.tuple.Fields fieldDeclaration) Create a new instance of SimpleNestedAggregate without a factory
	SimpleNestedAggregate(cascading.tuple.Fields fieldDeclaration, cascading.operation.SerFunction<cascading.tuple.type.CoercibleType<Node>,SimpleNestedAggregate.AggregateContext<Node>> factory) Create a new instance of SimpleNestedAggregate.

Method Summary

Modifier and Type	Method and Description
void	aggregate(SimpleNestedAggregate.AggregateContext<Node> context, Node node) This method receives each collected value to be applied to the current aggregation.
cascading.tuple.Tuple	complete(SimpleNestedAggregate.AggregateContext<Node> context) This method completes the aggregate operation and insert the results into a Tuple instance.
SimpleNestedAggregate.AggregateContext<Node>	createContext(cascading.tuple.type.CoercibleType<Node> nestedCoercibleType)
cascading.tuple.Fields	getFieldDeclaration()
SimpleNestedAggregate.AggregateContext<Node>	resetContext(SimpleNestedAggregate.AggregateContext<Node> context) This method is called after NestedAggregate.complete(Object) so that any resources can be freed and the result context instance can be used in the next aggregation.
protected void	setFactory(cascading.operation.SerFunction<cascading.tuple.type.CoercibleType<Node>,SimpleNestedAggregate.AggregateContext<Node>> factory)
protected SimpleNestedAggregate<Node>	setFieldDeclaration(cascading.tuple.Fields fieldDeclaration)

Methods inherited from class java.lang.Object

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

Field Detail

fieldDeclaration

protected cascading.tuple.Fields fieldDeclaration

factory

protected cascading.operation.SerFunction<cascading.tuple.type.CoercibleType<Node>,SimpleNestedAggregate.AggregateContext<Node>> factory

Constructor Detail

SimpleNestedAggregate

@ConstructorProperties(value={"fieldDeclaration","factory"})
public SimpleNestedAggregate(cascading.tuple.Fields fieldDeclaration,
                                                                                          cascading.operation.SerFunction<cascading.tuple.type.CoercibleType<Node>,SimpleNestedAggregate.AggregateContext<Node>> factory)

Create a new instance of SimpleNestedAggregate.

The factory parameter provides new instances of SimpleNestedAggregate.AggregateContext.

Parameters:

fieldDeclaration - the fields this aggregate returns

factory - a supplier for new AggregateContext instances

SimpleNestedAggregate

@ConstructorProperties(value="fieldDeclaration")
protected SimpleNestedAggregate(cascading.tuple.Fields fieldDeclaration)

Create a new instance of SimpleNestedAggregate without a factory

The factory parameter provides new instances of SimpleNestedAggregate.AggregateContext.

Parameters:

fieldDeclaration - the fields this aggregate returns

SimpleNestedAggregate

protected SimpleNestedAggregate()

Create a new instance of SimpleNestedAggregate without a factory

The factory parameter provides new instances of SimpleNestedAggregate.AggregateContext.

Method Detail

setFactory

protected void setFactory(cascading.operation.SerFunction<cascading.tuple.type.CoercibleType<Node>,SimpleNestedAggregate.AggregateContext<Node>> factory)

getFieldDeclaration

public cascading.tuple.Fields getFieldDeclaration()

Specified by:

getFieldDeclaration in interface NestedAggregate<Node,SimpleNestedAggregate.AggregateContext<Node>>

Returns:

the fields this aggregate function will return

setFieldDeclaration

protected SimpleNestedAggregate<Node> setFieldDeclaration(cascading.tuple.Fields fieldDeclaration)

createContext

public SimpleNestedAggregate.AggregateContext<Node> createContext(cascading.tuple.type.CoercibleType<Node> nestedCoercibleType)

Specified by:

createContext in interface NestedAggregate<Node,SimpleNestedAggregate.AggregateContext<Node>>

Returns:

a new function specific context object

aggregate

public void aggregate(SimpleNestedAggregate.AggregateContext<Node> context,
                      Node node)

Description copied from interface: NestedAggregate

This method receives each collected value to be applied to the current aggregation.

Specified by:

aggregate in interface NestedAggregate<Node,SimpleNestedAggregate.AggregateContext<Node>>

Parameters:

context - the context object created by NestedAggregate.createContext(CoercibleType)

node - the Node container object that should be aggregated

complete

public cascading.tuple.Tuple complete(SimpleNestedAggregate.AggregateContext<Node> context)

Description copied from interface: NestedAggregate

This method completes the aggregate operation and insert the results into a Tuple instance.

Note the Tuple may be created (indirectly) by the NestedAggregate.createContext(CoercibleType) method and reused.

Specified by:

complete in interface NestedAggregate<Node,SimpleNestedAggregate.AggregateContext<Node>>

Parameters:

context - the context object created by NestedAggregate.createContext(CoercibleType)

Returns:

a Tuple containing the aggregate value(s), the Tuple may be reused

resetContext

public SimpleNestedAggregate.AggregateContext<Node> resetContext(SimpleNestedAggregate.AggregateContext<Node> context)

Description copied from interface: NestedAggregate

This method is called after NestedAggregate.complete(Object) so that any resources can be freed and the result context instance can be used in the next aggregation.

Specified by:

resetContext in interface NestedAggregate<Node,SimpleNestedAggregate.AggregateContext<Node>>

Parameters:

context - the context object created by NestedAggregate.createContext(CoercibleType)

Returns:

either a cleared or new context instance to be used in further aggregations