Package org.springframework.data.relational.core.conversion

Class MappingRelationalConverter

java.lang.Object

org.springframework.data.relational.core.conversion.AbstractRelationalConverter

org.springframework.data.relational.core.conversion.MappingRelationalConverter

All Implemented Interfaces:

Aware, ApplicationContextAware, EnvironmentCapable, RelationalConverter

Direct Known Subclasses:

BasicRelationalConverter, MappingJdbcConverter, MappingR2dbcConverter

public class MappingRelationalConverter
extends AbstractRelationalConverter
implements ApplicationContextAware, EnvironmentCapable

RelationalConverter that uses a MappingContext to apply sophisticated mapping of domain objects from RowDocument.

Since:

3.2

Author:

Mark Paluch, Jens Schauder, Chirag Tailor, Vincent Galloy, Chanhyeong Cho

See Also:

• MappingContext
• SimpleTypeHolder
• CustomConversions

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static interface	MappingRelationalConverter.AggregatePathValueProvider	MappingRelationalConverter.RelationalPropertyValueProvider extension to obtain values for AggregatePaths.
protected static interface	MappingRelationalConverter.ConversionContext	Conversion context defining an interface for graph-traversal-based conversion of row documents.
protected static class	MappingRelationalConverter.DefaultConversionContext	Conversion context holding references to simple MappingRelationalConverter.DefaultConversionContext.ValueConverter and MappingRelationalConverter.DefaultConversionContext.ContainerValueConverter.
protected static final class	MappingRelationalConverter.DocumentValueProvider	PropertyValueProvider to evaluate a SpEL expression if present on the property or simply accesses the field of the configured source RowDocument.
protected class	MappingRelationalConverter.ProjectingConversionContext	Projecting variant of MappingRelationalConverter.ConversionContext applying mapping-metadata rules from the related entity.
protected static interface	MappingRelationalConverter.RelationalPropertyValueProvider	Extended ParameterValueProvider that can report whether a property value is present and contextualize the instance for specific behavior like projection mapping in the context of a property.

Constructor Summary

Constructors

Constructor	Description
MappingRelationalConverter(RelationalMappingContext context)	Creates a new MappingRelationalConverter given the new RelationalMappingContext.
MappingRelationalConverter(RelationalMappingContext context, CustomConversions conversions)	Creates a new MappingRelationalConverter given the new RelationalMappingContext and CustomConversions.

Method Summary

Modifier and Type	Method	Description
<T> T	createInstance(PersistentEntity<T,RelationalPersistentProperty> entity, Function<Parameter<?,RelationalPersistentProperty>,Object> parameterValueProvider)	Create a new instance of PersistentEntity given ParameterValueProvider to obtain constructor properties.
protected <R> R	doReadProjection(MappingRelationalConverter.ConversionContext context, RowDocument document, EntityProjection<R,?> projection)
protected MappingRelationalConverter.ConversionContext	getConversionContext(ObjectPath path)	Creates a new MappingRelationalConverter.ConversionContext.
Environment	getEnvironment()
protected Object	getPotentiallyConvertedSimpleRead(Object value, TypeInformation<?> type)	Checks whether we have a custom conversion for the given simple object.
<T> PersistentPropertyPathAccessor<T>	getPropertyAccessor(PersistentEntity<T,?> persistentEntity, T instance)	Return a PersistentPropertyAccessor to access property values of the instance.
<M, D> EntityProjection<M,D>	introspectProjection(Class<M> resultType, Class<D> entityType)	Introspect the given result type in the context of the entity type whether the returned type is a projection and what property paths are participating in the projection.
protected <R> MappingRelationalConverter.ProjectingConversionContext	newProjectingConversionContext(EntityProjection<R,?> projection)
protected MappingRelationalConverter.RelationalPropertyValueProvider	newValueProvider(RowDocumentAccessor documentAccessor, ValueExpressionEvaluator evaluator, MappingRelationalConverter.ConversionContext context)
<R> R	project(EntityProjection<R,?> projection, RowDocument document)	Apply a projection to RowDocument and return the projection return type R.
<R> R	read(Class<R> type, RowDocument source)	Read a RowDocument into the requested aggregate type.
protected <S> S	read(TypeInformation<S> type, RowDocument source)
protected <S> S	readAggregate(MappingRelationalConverter.ConversionContext context, RowDocumentAccessor documentAccessor, TypeInformation<? extends S> typeHint)	Conversion method to materialize an object from a document.
protected <S> S	readAggregate(MappingRelationalConverter.ConversionContext context, RowDocument document, TypeInformation<? extends S> typeHint)	Conversion method to materialize an object from a document.
protected Object	readCollectionOrArray(MappingRelationalConverter.ConversionContext context, Collection<?> source, TypeInformation<?> targetType)	Reads the given Collection into a collection of the given TypeInformation.
protected Map<Object,Object>	readMap(MappingRelationalConverter.ConversionContext context, Map<?,?> source, TypeInformation<?> targetType)	Reads the given RowDocument into a Map. will recursively resolve nested Maps as well.
Object	readValue(Object value, TypeInformation<?> type)	Read a relational value into the desired destination type.
void	setApplicationContext(ApplicationContext applicationContext)
Object	writeValue(Object value, TypeInformation<?> type)	Write a property value into a relational type that can be stored natively.

Methods inherited from class org.springframework.data.relational.core.conversion.AbstractRelationalConverter

getConversions, getConversionService, getEntityInstantiators, getMappingContext

Methods inherited from class java.lang.Object

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

Constructor Details

MappingRelationalConverter

public MappingRelationalConverter(RelationalMappingContext context)

Creates a new MappingRelationalConverter given the new RelationalMappingContext.

Parameters:

context - must not be null.

MappingRelationalConverter

public MappingRelationalConverter(RelationalMappingContext context,
 CustomConversions conversions)

Creates a new MappingRelationalConverter given the new RelationalMappingContext and CustomConversions.

Parameters:

context - must not be null.

conversions - must not be null.

Method Details

setApplicationContext

public void setApplicationContext(ApplicationContext applicationContext)
                           throws BeansException

Specified by:

setApplicationContext in interface ApplicationContextAware

Throws:

BeansException

getEnvironment

public Environment getEnvironment()

Specified by:

getEnvironment in interface EnvironmentCapable

getConversionContext

protected MappingRelationalConverter.ConversionContext getConversionContext(ObjectPath path)

Creates a new MappingRelationalConverter.ConversionContext.

Returns:

the MappingRelationalConverter.ConversionContext.

getPropertyAccessor

public <T> PersistentPropertyPathAccessor<T> getPropertyAccessor(PersistentEntity<T,?> persistentEntity,
 T instance)

Description copied from interface: RelationalConverter

Return a PersistentPropertyAccessor to access property values of the instance.

Specified by:

getPropertyAccessor in interface RelationalConverter

Parameters:

persistentEntity - the kind of entity to operate on. Must not be null.

instance - the instance to operate on. Must not be null.

Returns:

guaranteed to be not null.

introspectProjection

public <M,
D> EntityProjection<M,D> introspectProjection(Class<M> resultType,
 Class<D> entityType)

Description copied from interface: RelationalConverter

Introspect the given result type in the context of the entity type whether the returned type is a projection and what property paths are participating in the projection.

Specified by:

introspectProjection in interface RelationalConverter

Parameters:

resultType - the type to project on. Must not be null.

entityType - the source domain type. Must not be null.

Returns:

the introspection result.

See Also:

• EntityProjectionIntrospector.introspect(Class, Class)

project

public <R> R project(EntityProjection<R,?> projection,
 RowDocument document)

Description copied from interface: RelationalConverter

Apply a projection to RowDocument and return the projection return type R. Non-projecting descriptors fall back to regular object materialization.

Specified by:

project in interface RelationalConverter

Parameters:

projection - the projection descriptor, must not be null.

document - must not be null.

Returns:

a new instance of the projection return type R.

newProjectingConversionContext

protected <R>
MappingRelationalConverter.ProjectingConversionContext newProjectingConversionContext(EntityProjection<R,?> projection)

doReadProjection

protected <R> R doReadProjection(MappingRelationalConverter.ConversionContext context,
 RowDocument document,
 EntityProjection<R,?> projection)

read

public <R> R read(Class<R> type,
 RowDocument source)

Read a RowDocument into the requested aggregate type.

Specified by:

read in interface RelationalConverter

Type Parameters:

R - aggregate type.

Parameters:

type - target aggregate type.

source - source RowDocument.

Returns:

the converted object.

read

protected <S> S read(TypeInformation<S> type,
 RowDocument source)

readAggregate

protected <S> S readAggregate(MappingRelationalConverter.ConversionContext context,
 RowDocument document,
 TypeInformation<? extends S> typeHint)

Conversion method to materialize an object from a document. Can be overridden by subclasses.

Parameters:

context - must not be null

document - must not be null

typeHint - the TypeInformation to be used to unmarshall this RowDocument.

Returns:

the converted object, will never be null.

readAggregate

protected <S> S readAggregate(MappingRelationalConverter.ConversionContext context,
 RowDocumentAccessor documentAccessor,
 TypeInformation<? extends S> typeHint)

Conversion method to materialize an object from a document. Can be overridden by subclasses.

Parameters:

context - must not be null

documentAccessor - must not be null

typeHint - the TypeInformation to be used to unmarshall this RowDocument.

Returns:

the converted object, will never be null.

readMap

protected Map<Object,Object> readMap(MappingRelationalConverter.ConversionContext context,
 Map<?,?> source,
 TypeInformation<?> targetType)

Reads the given RowDocument into a Map. will recursively resolve nested Maps as well. Can be overridden by subclasses.

Parameters:

context - must not be null

source - must not be null

targetType - the Map TypeInformation to be used to unmarshall this RowDocument.

Returns:

the converted Map, will never be null.

readCollectionOrArray

protected Object readCollectionOrArray(MappingRelationalConverter.ConversionContext context,
 Collection<?> source,
 TypeInformation<?> targetType)

Reads the given Collection into a collection of the given TypeInformation. Can be overridden by subclasses.

Parameters:

context - must not be null

source - must not be null

targetType - the Map TypeInformation to be used to unmarshall this RowDocument.

Returns:

the converted Collection or array, will never be null.

createInstance

public <T> T createInstance(PersistentEntity<T,RelationalPersistentProperty> entity,
 Function<Parameter<?,RelationalPersistentProperty>,Object> parameterValueProvider)

Description copied from interface: RelationalConverter

Create a new instance of PersistentEntity given ParameterValueProvider to obtain constructor properties.

Specified by:

createInstance in interface RelationalConverter

Type Parameters:

T - the type of entity to create.

Parameters:

entity - the kind of entity to create. Must not be null.

parameterValueProvider - a function that provides the value to pass to a constructor, given a Parameter. Must not be null.

Returns:

the instantiated entity. Guaranteed to be not null.

newValueProvider

protected MappingRelationalConverter.RelationalPropertyValueProvider newValueProvider(RowDocumentAccessor documentAccessor,
 ValueExpressionEvaluator evaluator,
 MappingRelationalConverter.ConversionContext context)

readValue

@Nullable
public Object readValue(@Nullable
 Object value,
 TypeInformation<?> type)

Description copied from interface: RelationalConverter

Read a relational value into the desired destination type.

Specified by:

readValue in interface RelationalConverter

Parameters:

value - a value as it is returned by the driver accessing the persistence store. May be null.

type - TypeInformation into which the value is to be converted. Must not be null.

Returns:

The converted value. May be null.

getPotentiallyConvertedSimpleRead

protected Object getPotentiallyConvertedSimpleRead(Object value,
 TypeInformation<?> type)

Checks whether we have a custom conversion for the given simple object. Converts the given value if so, applies Enum handling or returns the value as is.

Parameters:

value - to be converted. May be null..

type - TypeInformation into which the value is to be converted. Must not be null.

Returns:

the converted value if a conversion applies or the original value. Might return null.

writeValue

@Nullable
public Object writeValue(@Nullable
 Object value,
 TypeInformation<?> type)

Description copied from interface: RelationalConverter

Write a property value into a relational type that can be stored natively.

Specified by:

writeValue in interface RelationalConverter

Parameters:

value - a value as it is used in the object model. May be null.

type - TypeInformation into which the value is to be converted. Must not be null.

Returns:

The converted value. May be null.