com.neurosys.etl.common.transformers

Class AbstractEntityTransformer<NODE,NODE_IDENTIFIER,ENTITY>

java.lang.Object

com.neurosys.etl.process.EventAwareProcess

com.neurosys.etl.common.transformers.AbstractEntityTransformer<NODE,NODE_IDENTIFIER,ENTITY>

Type Parameters:

NODE - as source Type

NODE_IDENTIFIER - as the type used to identify the NODE being analyzed. Uses this using identifyNode(Object)

ENTITY - as destination entity type

All Implemented Interfaces:

IdempotentAware, ModeAware, Process, Serializable, org.apache.commons.collections.Transformer

Direct Known Subclasses:

AbstractEntityToTupleTransformer, AbstractObjectToEntityTransformer, AbstractTupleToEntityTransformer

public abstract class AbstractEntityTransformer<NODE,NODE_IDENTIFIER,ENTITY>
extends EventAwareProcess
implements ModeAware, IdempotentAware, org.apache.commons.collections.Transformer, Serializable

Boiler plate common methods for an EventAwareProcess, ModeAware Transformer
Note: A NODE is the smallest aspect of an entity that is available for processing.

Author:

Arjun Dhar

See Also:

Must call init if not used via Spring, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.neurosys.etl.process.Process

Process.Event, Process.EventPoint

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<?,Mapper>	columnFieldMapping Mapper from Tuple Column Index/Field Name to a particular field (one to one); index # starts @ 0
protected boolean	idempotent By default if run changes will propogate
protected Mode	mode Mode ; defaults to Mode.INSERT.
protected List<Mode>	modesSupported What all modes does this Reader support Default All defined in Mode
protected Map<String,?>	nestedObjectInitMap (Optional) Map that allows to instantiate an object for a nested property in the main Entity.
protected List<Mapper>	nonAssociatedMappers Mapper that uses the tuple/Row to extract data to map to particular column

Fields inherited from class com.neurosys.etl.process.EventAwareProcess

listeners, processState

Constructor Summary

Constructors

Constructor and Description
AbstractEntityTransformer()
AbstractEntityTransformer(AbstractEntityTransformer t)

Method Summary

Modifier and Type	Method and Description
protected boolean	consumeIntermediateObjects(NODE_IDENTIFIER nodeIdentifier, Map<String,Object> intermediateObjects, Mapper mapper, Queue<NODE_IDENTIFIER> nodesForReProcessing) For Mappers with IntermediateResultMapperBehavior, process and set them with the required intermediate objects
Map<?,Mapper>	getColumnFieldMapping() Mapper from Tuple Column Index/Field Name to a particular field (one to one); index # starts @ 0
org.apache.commons.collections.Transformer	getEntityAccessTransformer() Allow query sub-properties etc if provided (A clone of this is used in getValue(Object, Object, Mapper))
Mode	getMode() Mode ; defaults to Mode.INSERT.
List<Mode>	getModesSupported() Get the Modes supported by the instance
Map<String,?>	getNestedObjectInitMap() (Optional) Map that allows to instantiate an object for a nested property in the main Entity.
List<Mapper>	getNonAssiciatedMappers() Mapper that uses the tuple/Row to extract data to map to particular column
List<Mapper>	getNonAssociatedMappers() Mapper that uses the tuple/Row to extract data to map to particular column
protected Object	getValue(Object propertyKey, NODE e, Mapper mapper) Extract the value from the Entity. If an EntityChainAccessTransformer is defined then that is used or else default PropertyUtils.getProperty(Object, String) is used.
protected abstract String	identifyNode(NODE_IDENTIFIER node) Identify a node/cell that is being processed.
void	init()
protected abstract ENTITY	init(NODE rawInput, Map<String,Object> intermediateObjects) Create the core Entity and also initialize intermediateObjects (nested objects) with core entities
boolean	isIdempotent() By default if run changes will propogate
protected void	nestedInit(Object entity, String fieldName, Object value) (Optional) Map that allows to instantiate an object for a nested property in the main Entity.
protected Object	processValue(Mapper mapper, Object value) Process field data for Chains, Transformers, Predicate filters etc
void	setColumnFieldMapping(Map<?,Mapper> columnFieldMapping) Mapper from Tuple Column Index/Field Name to a particular field (one to one); index # starts @ 0
protected void	setEntity(ENTITY entity, Mapper mapper, Object value) Set the entity with the value for the field that is mapped
void	setEntityAccessTransformer(org.apache.commons.collections.Transformer entityAccessTransformer) Allow query sub-properties etc if provided (A clone of this is used in getValue(Object, Object, Mapper))
void	setIdempotent(boolean idempotent)
void	setMode(Mode mode) Mode ; defaults to Mode.INSERT.
void	setModesSupported(List<Mode> modesSupported)
void	setNestedObjectInitMap(Map<String,?> nestedObjectInitMap) (Optional) Map that allows to instantiate an object for a nested property in the main Entity.
void	setNonAssociatedMappers(List<Mapper> nonAssociatedMappers) Mapper that uses the tuple/Row to extract data to map to particular column

Methods inherited from class com.neurosys.etl.process.EventAwareProcess

addListener, getListeners, onChangeHandler, setListeners

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.collections.Transformer

transform

Field Detail

columnFieldMapping

protected Map<?,Mapper> columnFieldMapping

Mapper from Tuple Column Index/Field Name to a particular field (one to one); index # starts @ 0

nonAssociatedMappers

protected List<Mapper> nonAssociatedMappers

Mapper that uses the tuple/Row to extract data to map to particular column

nestedObjectInitMap

protected Map<String,?> nestedObjectInitMap

(Optional) Map that allows to instantiate an object for a nested property in the main Entity. The key is the name of the property, value can be a Class, instance itself or a Transformer that accepts an Object array {key as field name, value of field}, and generates an instance. One can also pre-init in init(Object, Map). This is used when @ runtime we need a nested object created for a value being set.

See Also:

for the implementation

mode

protected Mode mode

Mode ; defaults to Mode.INSERT. Mappers that are ModeAware will consult this field in derived implementations.

idempotent

protected boolean idempotent

By default if run changes will propogate

Default value:

true

modesSupported

protected List<Mode> modesSupported

What all modes does this Reader support
Default All defined in Mode

Constructor Detail

AbstractEntityTransformer

public AbstractEntityTransformer()

AbstractEntityTransformer

public AbstractEntityTransformer(AbstractEntityTransformer t)

Method Detail

getValue

protected Object getValue(Object propertyKey,
                          NODE e,
                          Mapper mapper)
                   throws Exception

Extract the value from the Entity.
If an EntityChainAccessTransformer is defined then that is used or else default PropertyUtils.getProperty(Object, String) is used.

Parameters:

propertyKey - as Id or name of Property/field to extract from the NODE

NODE -

mapper - as Mapper @nullable true

Returns:

Throws:

Exception

identifyNode

protected abstract String identifyNode(NODE_IDENTIFIER node)

Identify a node/cell that is being processed. Used for Log and debug purposes.

Parameters:

type - NODE_IDENTIFIER

Returns:

String

init

@PostConstruct
public void init()

setEntity

protected void setEntity(ENTITY entity,
                         Mapper mapper,
                         Object value)
                  throws Exception

Set the entity with the value for the field that is mapped

Parameters:

entity -

mapper - as Mapper for MapperBehaviors and Mapper.getFieldName()

value -

Throws:

Exception - TODO: Add unit test case, for an Entity with Integer field type but passing Double field value

consumeIntermediateObjects

protected boolean consumeIntermediateObjects(NODE_IDENTIFIER nodeIdentifier,
                                             Map<String,Object> intermediateObjects,
                                             Mapper mapper,
                                             Queue<NODE_IDENTIFIER> nodesForReProcessing)

For Mappers with IntermediateResultMapperBehavior, process and set them with the required intermediate objects

Parameters:

NODE - type to represent the Column or Cell

intermediateObjects - as Map of intermediate object variable name and the Value

mapper - as Mapper

nodesForReProcessing - as Queue that Q's up COLs/Cells that may not be ready for processing, since the dependent col is yet to be processed

Returns:

boolean; if true implies the COL/Cell was processed successfully else it implies it was Q'd up

processValue

protected Object processValue(Mapper mapper,
                              Object value)
                       throws BreakChainException,
                              ContinueProcessingException

Process field data for Chains, Transformers, Predicate filters etc

Parameters:

mapper - as Mapper

value - as Object

Returns:

Throws:

BreakChainException, - ContinueProcessingException

BreakChainException

ContinueProcessingException

init

protected abstract ENTITY init(NODE rawInput,
                               Map<String,Object> intermediateObjects)

Create the core Entity and also initialize intermediateObjects (nested objects) with core entities

Parameters:

intermediateObjects - the Map into which we can pre-initialize stuff

Returns:

entity object

nestedInit

protected void nestedInit(Object entity,
                          String fieldName,
                          Object value)
                   throws Exception

(Optional) Map that allows to instantiate an object for a nested property in the main Entity. One can also pre-init in init(Object, Map). This is used when @ runtime we need a nested object created for a value being set.

Parameters:

entity - as the entity that contains the nested entity (immediate parent entity)

fieldName - String for the nested entity name. Example "a.b.c"

value - of the nested entity that will be set on the leaf/last nested part TODO: Add unit test case

Throws:

Exception

getColumnFieldMapping

public Map<?,Mapper> getColumnFieldMapping()

Mapper from Tuple Column Index/Field Name to a particular field (one to one); index # starts @ 0

setColumnFieldMapping

public void setColumnFieldMapping(Map<?,Mapper> columnFieldMapping)

Mapper from Tuple Column Index/Field Name to a particular field (one to one); index # starts @ 0

getNonAssiciatedMappers

public List<Mapper> getNonAssiciatedMappers()

Mapper that uses the tuple/Row to extract data to map to particular column

setNonAssociatedMappers

public void setNonAssociatedMappers(List<Mapper> nonAssociatedMappers)

Mapper that uses the tuple/Row to extract data to map to particular column

getNonAssociatedMappers

public List<Mapper> getNonAssociatedMappers()

Mapper that uses the tuple/Row to extract data to map to particular column

getNestedObjectInitMap

public Map<String,?> getNestedObjectInitMap()

(Optional) Map that allows to instantiate an object for a nested property in the main Entity. The key is the name of the property, value can be a Class, instance itself or a Transformer that accepts an Object array {key as field name, value of field}, and generates an instance. One can also pre-init in init(Object, Map). This is used when @ runtime we need a nested object created for a value being set.

See Also:

for the implementation

setNestedObjectInitMap

public void setNestedObjectInitMap(Map<String,?> nestedObjectInitMap)

(Optional) Map that allows to instantiate an object for a nested property in the main Entity. The key is the name of the property, value can be a Class, instance itself or a Transformer that accepts an Object array {key as field name, value of field}, and generates an instance. One can also pre-init in init(Object, Map). This is used when @ runtime we need a nested object created for a value being set.

See Also:

for the implementation

getMode

public Mode getMode()

Mode ; defaults to Mode.INSERT. Mappers that are ModeAware will consult this field in derived implementations.

Specified by:

getMode in interface ModeAware

See Also:

Mode

isIdempotent

public boolean isIdempotent()

By default if run changes will propogate

Specified by:

isIdempotent in interface IdempotentAware

Default value:

true

setMode

public void setMode(Mode mode)

Mode ; defaults to Mode.INSERT. Mappers that are ModeAware will consult this field in derived implementations.
Should be called ideally after {setColumnFieldMapping(Map) and {setNonAssociatedMappers(List) are set
If initialized via a Spring Context then it will automatically be initialized correctly.

Specified by:

setMode in interface ModeAware

setIdempotent

public void setIdempotent(boolean idempotent)

Specified by:

setIdempotent in interface IdempotentAware

getModesSupported

public List<Mode> getModesSupported()

Description copied from interface: ModeAware

Get the Modes supported by the instance

Specified by:

getModesSupported in interface ModeAware

Returns:

setModesSupported

public void setModesSupported(List<Mode> modesSupported)

getEntityAccessTransformer

public org.apache.commons.collections.Transformer getEntityAccessTransformer()

Allow query sub-properties etc if provided (A clone of this is used in getValue(Object, Object, Mapper))

See Also:

getValue(Object, Object, Mapper)

Can be null:

true

setEntityAccessTransformer

public void setEntityAccessTransformer(org.apache.commons.collections.Transformer entityAccessTransformer)

Allow query sub-properties etc if provided (A clone of this is used in getValue(Object, Object, Mapper))

See Also:

getValue(Object, Object, Mapper)

Can be null:

true