net.sf.morph.transform.converters
Class IdentityConverter

java.lang.Object
  net.sf.morph.transform.transformers.BaseTransformer
      net.sf.morph.transform.converters.IdentityConverter

All Implemented Interfaces:

net.sf.composite.Component, Converter, DecoratedConverter, DecoratedTransformer, ExplicitTransformer, Transformer

Direct Known Subclasses:

ImmutableTypesOnlyIdentityConverter

public class IdentityConverter
extends BaseTransformer
implements DecoratedConverter, ExplicitTransformer

Converts objects that are already instances of the destination class by simply returning the object unchanged.

Since:

Dec 31, 2004

Author:

Matt Sgarlata

Field Summary

static java.lang.Class[]

DEFAULT_SOURCE_AND_DESTINATION_TYPES Default source/destination types

Fields inherited from class net.sf.morph.transform.transformers.BaseTransformer

destinationClasses, log, sourceClasses

Fields inherited from interface net.sf.morph.transform.Transformer

TRANSFORMATION_TYPE_CONVERT, TRANSFORMATION_TYPE_COPY

Fields inherited from interface net.sf.morph.transform.Transformer

TRANSFORMATION_TYPE_CONVERT, TRANSFORMATION_TYPE_COPY

Constructor Summary

IdentityConverter()
Create a new IdentityConverter.

IdentityConverter(java.lang.Class[] sourceAndDestinationClasses)
Create a new IdentityConverter.

Method Summary

protected java.lang.Object	convertImpl(java.lang.Class destinationClass, java.lang.Object source, java.util.Locale locale) The implementation of the convert method, which may omit the invalid argument checks already performed by this base class.
protected java.lang.Class[]	getDestinationClassesImpl() Transformer.getDestinationClasses() implementation template method.
protected java.lang.Class[]	getSourceClassesImpl() Transformer.getSourceClasses() implementation template method.
protected boolean	isPerformingLogging() Indicates if calls to the main transformation methods (convert, copy) will cause a log message to be recorded
protected boolean	isTransformableImpl(java.lang.Class destinationType, java.lang.Class sourceType) Default implementation for Transformer#isTransformable(Class, Class) that assumes that each source type can be converted into each destination type.
protected boolean	isWrappingRuntimeExceptions() Indicates whether runtime exceptions should be wrapped as TransformationExceptions.
void	setDestinationClasses(java.lang.Class[] destinationClasses) Configures the destinationClasses property of this transformer.
void	setSourceClasses(java.lang.Class[] sourceClasses) Configures the sourceClasses property of this transformer.

Methods inherited from class net.sf.morph.transform.transformers.BaseTransformer

clone, convert, convert, copy, copy, copyImpl, createDefaultReflector, createNewInstance, createNewInstanceImpl, createReusableSource, equals, equals, equalsUnidirectionalTest, getDestinationClasses, getInstantiatingReflector, getLocale, getLog, getNestedTransformer, getReflector, getReflector, getSourceClasses, getTransformableCallCache, getTransformerName, initialize, initializeImpl, isAutomaticallyHandlingNulls, isCachingIsTransformableCalls, isImpreciseTransformation, isImpreciseTransformationImpl, isInitialized, isTransformable, setCachingIsTransformableCalls, setInitialized, setLog, setNestedTransformer, setReflector, setTransformableCallCache, setTransformerName, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.morph.transform.DecoratedConverter

convert, equals, equals

Methods inherited from interface net.sf.morph.transform.Converter

convert

Methods inherited from interface net.sf.morph.transform.Transformer

getDestinationClasses, getSourceClasses

Methods inherited from interface net.sf.morph.transform.Transformer

getDestinationClasses, getSourceClasses

Methods inherited from interface net.sf.morph.transform.ExplicitTransformer

isTransformable

Field Detail

DEFAULT_SOURCE_AND_DESTINATION_TYPES

public static final java.lang.Class[] DEFAULT_SOURCE_AND_DESTINATION_TYPES

Default source/destination types

Constructor Detail

IdentityConverter

public IdentityConverter()

Create a new IdentityConverter.

IdentityConverter

public IdentityConverter(java.lang.Class[] sourceAndDestinationClasses)

Create a new IdentityConverter.

Parameters:

sourceAndDestinationClasses -

Method Detail

isTransformableImpl

protected boolean isTransformableImpl(java.lang.Class destinationType,
                                      java.lang.Class sourceType)
                               throws java.lang.Exception

Default implementation for Transformer#isTransformable(Class, Class) that assumes that each source type can be converted into each destination type.

Overrides:

isTransformableImpl in class BaseTransformer

Parameters:

destinationType - the destination type to test

sourceType - the source type to test

Returns:

whether the destination type is transformable to the source type

Throws:

TransformationException - if it could not be determined if sourceType is transformable into destinationType

java.lang.Exception

convertImpl

protected java.lang.Object convertImpl(java.lang.Class destinationClass,
                                       java.lang.Object source,
                                       java.util.Locale locale)
                                throws java.lang.Exception

The implementation of the convert method, which may omit the invalid argument checks already performed by this base class. By default, this method creates a new instance of the destinationClass and copies information from the source to the destination. This implementation should be fine as-is for Copiers, but Converters will need to implement this method since they will not be implementing the copy method.

Overrides:

convertImpl in class BaseTransformer

locale - the locale in which the conversion should take place. for converters that are not locale-aware, the local argument can simply be ignored

Throws:

java.lang.Exception

isPerformingLogging

protected boolean isPerformingLogging()

Indicates if calls to the main transformation methods (convert, copy) will cause a log message to be recorded

Overrides:

isPerformingLogging in class BaseTransformer

Returns:

boolean

isWrappingRuntimeExceptions

protected boolean isWrappingRuntimeExceptions()

Indicates whether runtime exceptions should be wrapped as TransformationExceptions. By default, this method returns true.

Simple transformers in Morph that operate on JDK types like Numbers and Strings will usually set this value to true so that they throw TransformationExceptions if problems occur. More complex transformers that operate on graphs of objects are encouraged to set this value to false so that runtime exceptions are not wrapped. This way, problems accessing data will be expressed by the native API of a user's domain objects and avoid the need to catch Morph-specific exceptions (assuming the use of runtime exceptions in said domain objects).

Overrides:

isWrappingRuntimeExceptions in class BaseTransformer

Returns:

true

getSourceClassesImpl

protected java.lang.Class[] getSourceClassesImpl()
                                          throws java.lang.Exception

Transformer.getSourceClasses() implementation template method.

Specified by:

getSourceClassesImpl in class BaseTransformer

Returns:

Class[]

Throws:

java.lang.Exception

getDestinationClassesImpl

protected java.lang.Class[] getDestinationClassesImpl()
                                               throws java.lang.Exception

Transformer.getDestinationClasses() implementation template method.

Specified by:

getDestinationClassesImpl in class BaseTransformer

Returns:

Class[]

Throws:

java.lang.Exception

setDestinationClasses

public void setDestinationClasses(java.lang.Class[] destinationClasses)

Configures the destinationClasses property of this transformer. Note that this method should be called before the transformer is used. Otherwise, if another thread is in the middle of transforming an object graph and this method is called, the behavior of the transformer can change partway through the transformation.

Overrides:

setDestinationClasses in class BaseTransformer

Parameters:

destinationClasses - the new destinationClasses for this transformer

See Also:

BaseTransformer.setSourceClasses(java.lang.Class[])

setSourceClasses

public void setSourceClasses(java.lang.Class[] sourceClasses)

Configures the sourceClasses property of this transformer. Note that this method should be called before the transformer is used. Otherwise, if another thread is in the middle of transforming an object graph and this method is called, the behavior of the transformer can change partway through the transformation.

Overrides:

setSourceClasses in class BaseTransformer

Parameters:

sourceClasses - the new sourceClasses for this transformer

See Also:

BaseTransformer.setSourceClasses(java.lang.Class[])