net.sf.morph.transform.converters
Class ConverterDecorator

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

All Implemented Interfaces:

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

public class ConverterDecorator
extends BaseTransformer
implements DecoratedConverter, ExplicitTransformer

Decorates any Converter so that it implements DecoratedConverter. Example usage:

 Converter myConverter = new MyConverter();
 DecoratedConverter decoratedConverter = new DecoratedConverter(myConverter);
 
 // now use decoratedConverter instead of myConverter
 StringBuffer buffer = decoratedConverter.convert(StringBuffer.class, "no locale needed");
 

Since:

Dec 5, 2004

Author:

Matt Sgarlata

Field Summary

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

ConverterDecorator()
Create a new ConverterDecorator.

ConverterDecorator(Converter converter)
Create a new ConverterDecorator.

ConverterDecorator(Converter converter, java.util.Locale defaultLocale)
Create a new ConverterDecorator.

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.
java.util.Locale	getDefaultLocale() Get the defaultLocale.
protected java.lang.Class[]	getDestinationClassesImpl() Transformer.getDestinationClasses() implementation template method.
protected java.util.Locale	getLocale() Retrieves the current Locale if none is specified in the method arguments for a converter or copier.
Converter	getNestedConverter()
protected java.lang.Class[]	getSourceClassesImpl() Transformer.getSourceClasses() implementation template method.
protected boolean	isAutomaticallyHandlingNulls() Indicates whether null values will automatically be converted to null by this base class before even calling the subclass's BaseTransformer.convertImpl(Class, Object, Locale) method.
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	setDefaultLocale(java.util.Locale defaultLocale) Set the defaultLocale.
void	setDestinationClasses(java.lang.Class[] destinationClasses) Configures the destinationClasses property of this transformer.
void	setNestedConverter(Converter converter)
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, getLog, getNestedTransformer, getReflector, getReflector, getSourceClasses, getTransformableCallCache, getTransformerName, initialize, initializeImpl, isCachingIsTransformableCalls, isImpreciseTransformation, isImpreciseTransformationImpl, isInitialized, isPerformingLogging, 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

Constructor Detail

ConverterDecorator

public ConverterDecorator()

Create a new ConverterDecorator.

ConverterDecorator

public ConverterDecorator(Converter converter)

Create a new ConverterDecorator.

Parameters:

converter -

ConverterDecorator

public ConverterDecorator(Converter converter,
                          java.util.Locale defaultLocale)

Create a new ConverterDecorator.

Parameters:

converter -

defaultLocale -

Method Detail

getNestedConverter

public Converter getNestedConverter()

Returns:

Returns the converter.

setNestedConverter

public void setNestedConverter(Converter converter)

Parameters:

converter - The converter to set.

getDefaultLocale

public java.util.Locale getDefaultLocale()

Get the defaultLocale.

Returns:

Locale

setDefaultLocale

public void setDefaultLocale(java.util.Locale defaultLocale)

Set the defaultLocale.

Parameters:

defaultLocale - the Locale to set

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

See Also:

BaseTransformer.convertImpl(java.lang.Class, java.lang.Object, java.util.Locale)

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[])

getSourceClassesImpl

protected java.lang.Class[] getSourceClassesImpl()

Transformer.getSourceClasses() implementation template method.

Specified by:

getSourceClassesImpl in class BaseTransformer

Returns:

Class[]

See Also:

BaseTransformer.getSourceClassesImpl()

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.setDestinationClasses(java.lang.Class[])

getDestinationClassesImpl

protected java.lang.Class[] getDestinationClassesImpl()

Transformer.getDestinationClasses() implementation template method.

Specified by:

getDestinationClassesImpl in class BaseTransformer

Returns:

Class[]

See Also:

BaseTransformer.getDestinationClassesImpl()

isAutomaticallyHandlingNulls

protected boolean isAutomaticallyHandlingNulls()

Indicates whether null values will automatically be converted to null by this base class before even calling the subclass's BaseTransformer.convertImpl(Class, Object, Locale) method. Subclasses which depend on this behavior (which is all subclasses, by default) should include null as one of their source and destination classes so that the actual behavior of the transformer is consistent with the values that are returned by the BaseTransformer.isTransformable(Class, Class) method. The conversions will happen automatically even if the source and destination classes don't contain null, but for the sake of consistency the nulls should be included.

Overrides:

isAutomaticallyHandlingNulls in class BaseTransformer

Returns:

whether null values will automatically be converted to null by this base class before even calling the subclass's BaseTransformer.convertImpl(Class, Object, Locale) method

See Also:

BaseTransformer.isAutomaticallyHandlingNulls()

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

See Also:

BaseTransformer.isWrappingRuntimeExceptions()

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

getLocale

protected java.util.Locale getLocale()

Retrieves the current Locale if none is specified in the method arguments for a converter or copier. Attempts to load the Locale using Spring's org.springframework.context.i18n.LocaleContextHolder, if Spring is on the classpath. Otherwise, returns the default Locale by calling Locale.getDefault().

Overrides:

getLocale in class BaseTransformer

Returns:

the current Locale