com.neurosys.etl.common.transformers

Class EnsureAccessorExistsTransformer

java.lang.Object

com.neurosys.etl.common.transformers.UsesIntermediateObjectImpl<Map<String,Object>>

com.neurosys.etl.common.transformers.EnsureAccessorExistsTransformer

All Implemented Interfaces:

ContextAware<Map<String,Object>>, ModeAware, UsesIntermediateObject<Map<String,Object>>, Serializable, org.apache.commons.collections.Transformer

Direct Known Subclasses:

EnsureAttributeExistsTransformer

public class EnsureAccessorExistsTransformer
extends UsesIntermediateObjectImpl<Map<String,Object>>
implements ModeAware, org.apache.commons.collections.Transformer, Serializable

This Transformer does not apply any Transformation on the input itself (unless there is no intermediate object), however for the intermediate object passed it
ensures for an accessor chain like entity.attributes.attrib1
the necessary instances like "attributes" and "attrib1" exist else while setting one will get NullPointerExceptions.
You can override #updateChild(Object, Object, String) and write your own transformations on specific entities instance creation & setting.

This class has been made ModeAware to because when dealing with accessors it is often required to treat the related entity in context to the mode. TODO: Add unit test case

Author:

Arjun Dhar

See Also:

CreateEntityTransformer, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<String,Class>	accessClasses For each accessor in the accessor provide a Constructor Class
protected Map<String,Object>	accessValues For each accessor in the accessor provide a default Value. If it exists it will override accessClasses for same type.
protected Mode	mode
protected List<Mode>	modesSupported What all modes does this Reader support Default All defined in Mode

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

intermediateResults, resultNamesUsed, resultsThatAreOptional

Constructor Summary

Constructors

Constructor and Description
EnsureAccessorExistsTransformer()

Method Summary

Modifier and Type	Method and Description
Map<String,Class>	getAccessClasses() For each accessor in the accessor provide a Constructor Class
String	getAccessor() A dot separated list of entities.
Map<String,Object>	getAccessValues() For each accessor in the accessor provide a default Value. If it exists it will override accessClasses for same type.
Mode	getMode() The processing logic of the Reader may differ based n the fact it is intended to Update or Insert or Delete
List<Mode>	getModesSupported() Get the Modes supported by the instance
void	setAccessClasses(Map<String,Class> accessClasses) For each accessor in the accessor provide a Constructor Class
void	setAccessor(String accessor) A dot separated list of entities.
void	setAccessValues(Map<String,Object> accessValues) For each accessor in the accessor provide a default Value. If it exists it will override accessClasses for same type.
void	setMode(Mode mode)
void	setModesSupported(List<Mode> modesSupported)
protected boolean	skip(Object input) Custom logic to Skip Creation of Accessors based on input available.
Object	transform(Object input)
Object	transform(String accessor, Object input)
protected Object	updateChild(List parents, Object child, String property) Override how an instance is created in the Entity access chain

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

determineInput, getInputFromContext, getInterMediateResults, getResultNamesThatAreOptional, getResultNamesUsed, setIntermediateResults, setResultNamesThatAreOptional, setResultNamesUsed

Methods inherited from class java.lang.Object

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

Field Detail

mode

protected Mode mode

modesSupported

protected List<Mode> modesSupported

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

accessClasses

protected Map<String,Class> accessClasses

For each accessor in the accessor provide a Constructor Class

accessValues

protected Map<String,Object> accessValues

For each accessor in the accessor provide a default Value.
If it exists it will override accessClasses for same type.

Constructor Detail

EnsureAccessorExistsTransformer

public EnsureAccessorExistsTransformer()

Method Detail

transform

public Object transform(String accessor,
                        Object input)

transform

public Object transform(Object input)

Specified by:

transform in interface org.apache.commons.collections.Transformer

updateChild

protected Object updateChild(List parents,
                             Object child,
                             String property)
                      throws Exception

Override how an instance is created in the Entity access chain

Parameters:

parents - as List (in order of accessors; with the base entity @ 0th position and immediate parent @ last position)

child -

property -

Returns:

Object as updated child

Throws:

Exception

getAccessor

public String getAccessor()

A dot separated list of entities. Parent accessor first , attribute node last.
Example: attributes.attrib1

setAccessor

public void setAccessor(String accessor)

A dot separated list of entities. Parent accessor first , attribute node last.
Example: attributes.attrib1

getAccessClasses

public Map<String,Class> getAccessClasses()

For each accessor in the accessor provide a Constructor Class

setAccessClasses

public void setAccessClasses(Map<String,Class> accessClasses)

For each accessor in the accessor provide a Constructor Class

getAccessValues

public Map<String,Object> getAccessValues()

For each accessor in the accessor provide a default Value.
If it exists it will override accessClasses for same type.

setAccessValues

public void setAccessValues(Map<String,Object> accessValues)

For each accessor in the accessor provide a default Value.
If it exists it will override accessClasses for same type.

skip

protected boolean skip(Object input)

Custom logic to Skip Creation of Accessors based on input available.
By default if input is null it will those a ContinueProcessingException

Parameters:

input -

Returns:

getMode

public Mode getMode()

Description copied from interface: ModeAware

The processing logic of the Reader may differ based n the fact it is intended to Update or Insert or Delete

Specified by:

getMode in interface ModeAware

See Also:

Mode

Default value:

Mode.INSERT

setMode

public void setMode(Mode mode)

Specified by:

setMode in interface ModeAware

Default value:

Mode.INSERT

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)