com.neurosys.etl.common.transformers

Class ObjectArrayToEntityTransformer<ENTITY>

java.lang.Object

com.neurosys.etl.process.EventAwareProcess

com.neurosys.etl.common.transformers.AbstractEntityTransformer<TUPLE,CELL,ENTITY>

com.neurosys.etl.common.transformers.AbstractTupleToEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer<ENTITY>

Type Parameters:

ENTITY -

All Implemented Interfaces:

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

Direct Known Subclasses:

QueryResultArrayToEntityTransformer

public class ObjectArrayToEntityTransformer<ENTITY>
extends AbstractTupleToEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

Convert Object[] into an Entity.
Useful to convert raw data bindings from an OR result (Object[]) to an Entity. We may not want to fetch all the fields and all the relation for a given query but choose to keep the query simple to use to deal with entities only.

Example: SELECT E from entity E WHERE e.sku='123'
Lets assume, E has relations with other tables and results in other queries being fired by the OR framework, to satisfy its relationships. In many cases we may not desire all the fields, but also don't want to work with the laborious task of Data mapping in code from Array to entity etc.
We can limit the actual call by Modifying the original query to fetch only the Fields mention in AbstractEntityTransformer.getColumnFieldMapping() and then in the result Array simply map them into a proxy object we create.

Author:

Arjun Dhar

See Also:

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 Class<ENTITY>	type Intended result entity type

Fields inherited from class com.neurosys.etl.common.transformers.AbstractEntityTransformer

columnFieldMapping, idempotent, mode, modesSupported, nestedObjectInitMap, nonAssociatedMappers

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

listeners, processState

Constructor Summary

Constructors

Constructor and Description
ObjectArrayToEntityTransformer()
ObjectArrayToEntityTransformer(Class<ENTITY> type)
ObjectArrayToEntityTransformer(Class<ENTITY> type, List<String> fieldNames, boolean inverse) Internally will AbstractEntityTransformer.setColumnFieldMapping(Map) using the field names.
ObjectArrayToEntityTransformer(Class<ENTITY> type, Map<Integer,Mapper> columnFieldMapping)
ObjectArrayToEntityTransformer(ObjectArrayToEntityTransformer t)

Method Summary

Modifier and Type	Method and Description
protected int	getColumnIndex(com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell col)
protected Iterator<com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell>	getColumns(Object[] row)
static Field[]	getDeclaredFields(Class c)
protected Object[]	getTuple(Object rawTupleInput) The input to this Transformer is expected to be Object[] type
protected int	getTupleIndex(Object[] row)
protected int	getTupleIndexFromCol(com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell col)
Class<ENTITY>	getType() Intended result entity type
protected Object	getValue(com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell col, Mapper mapper) Ignores Mapper
protected ENTITY	init(Object[] rawInput, Map<String,Object> intermediateObjects) Create the core Entity and also initialize intermediateObjects (nested objects) with core entities
void	setType(Class<ENTITY> type) Intended result entity type

Methods inherited from class com.neurosys.etl.common.transformers.AbstractTupleToEntityTransformer

identifyNode, transform

Methods inherited from class com.neurosys.etl.common.transformers.AbstractEntityTransformer

consumeIntermediateObjects, getColumnFieldMapping, getEntityAccessTransformer, getMode, getModesSupported, getNestedObjectInitMap, getNonAssiciatedMappers, getNonAssociatedMappers, getValue, init, isIdempotent, nestedInit, processValue, setColumnFieldMapping, setEntity, setEntityAccessTransformer, setIdempotent, setMode, setModesSupported, setNestedObjectInitMap, setNonAssociatedMappers

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

Field Detail

type

protected Class<ENTITY> type

Intended result entity type

Constructor Detail

ObjectArrayToEntityTransformer

public ObjectArrayToEntityTransformer()

ObjectArrayToEntityTransformer

public ObjectArrayToEntityTransformer(ObjectArrayToEntityTransformer t)

ObjectArrayToEntityTransformer

public ObjectArrayToEntityTransformer(Class<ENTITY> type)

ObjectArrayToEntityTransformer

public ObjectArrayToEntityTransformer(Class<ENTITY> type,
                                      List<String> fieldNames,
                                      boolean inverse)

Internally will AbstractEntityTransformer.setColumnFieldMapping(Map) using the field names. If inverse is true then it will exclude the fieldNames and the columns will be in ascending order of the field name (case insensitive)

Parameters:

type - as Class for ENTITY

fieldNames - as List of field Names

inverse - as boolean : If true, will invert the field mapping and only fetch the fields for the entity that are not in the field list / AbstractEntityTransformer.getColumnFieldMapping()

ObjectArrayToEntityTransformer

public ObjectArrayToEntityTransformer(Class<ENTITY> type,
                                      Map<Integer,Mapper> columnFieldMapping)

Method Detail

getDeclaredFields

public static Field[] getDeclaredFields(Class c)

getTupleIndex

protected int getTupleIndex(Object[] row)

Specified by:

getTupleIndex in class AbstractTupleToEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

getTupleIndexFromCol

protected int getTupleIndexFromCol(com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell col)

Specified by:

getTupleIndexFromCol in class AbstractTupleToEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

getColumnIndex

protected int getColumnIndex(com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell col)

Specified by:

getColumnIndex in class AbstractTupleToEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

getTuple

protected Object[] getTuple(Object rawTupleInput)

The input to this Transformer is expected to be Object[] type

Specified by:

getTuple in class AbstractTupleToEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

getColumns

protected Iterator<com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell> getColumns(Object[] row)

Specified by:

getColumns in class AbstractTupleToEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

getValue

protected Object getValue(com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell col,
                          Mapper mapper)
                   throws Exception

Ignores Mapper

Specified by:

getValue in class AbstractTupleToEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

Parameters:

col - as CELL

mapper - as Mapper @nullable true

Returns:

Throws:

Exception

init

protected ENTITY init(Object[] rawInput,
                      Map<String,Object> intermediateObjects)

Description copied from class: AbstractEntityTransformer

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

Specified by:

init in class AbstractEntityTransformer<Object[],com.neurosys.etl.common.transformers.ObjectArrayToEntityTransformer.Cell,ENTITY>

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

Returns:

entity object

getType

public Class<ENTITY> getType()

Intended result entity type

setType

public void setType(Class<ENTITY> type)

Intended result entity type