net.sf.morph.transform.converters
Class IdentityConverter

java.lang.Object
  extended by net.sf.morph.transform.transformers.BaseTransformer
      extended by 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[])


Copyright © 2004-2008.