org.springframework.data.relational.core.conversion

Interface RelationalConverter

All Known Implementing Classes:

BasicRelationalConverter

public interface RelationalConverter

A RelationalConverter is responsible for converting for values to the native relational representation and vice versa.

Author:

Mark Paluch, Jens Schauder

Method Summary

Modifier and Type	Method and Description
<T> T	createInstance(PersistentEntity<T,RelationalPersistentProperty> entity, Function<PreferredConstructor.Parameter<?,RelationalPersistentProperty>,Object> parameterValueProvider) Create a new instance of PersistentEntity given ParameterValueProvider to obtain constructor properties.
ConversionService	getConversionService() Returns the underlying ConversionService used by the converter.
MappingContext<? extends RelationalPersistentEntity<?>,? extends RelationalPersistentProperty>	getMappingContext() Returns the underlying MappingContext used by the converter.
<T> PersistentPropertyAccessor<T>	getPropertyAccessor(PersistentEntity<T,?> persistentEntity, T instance) Return a PersistentPropertyAccessor to access property values of the instance.
Object	readValue(Object value, TypeInformation<?> type) Read a relational value into the desired destination type.
Object	writeValue(Object value, TypeInformation<?> type) Write a property value into a relational type that can be stored natively.

Method Detail

getMappingContext

MappingContext<? extends RelationalPersistentEntity<?>,? extends RelationalPersistentProperty> getMappingContext()

Returns the underlying MappingContext used by the converter.

Returns:

never null

getConversionService

ConversionService getConversionService()

Returns the underlying ConversionService used by the converter.

Returns:

never null.

createInstance

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

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

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 PreferredConstructor.Parameter. Must not be null.

Returns:

the instantiated entity. Guaranteed to be not null.

getPropertyAccessor

<T> PersistentPropertyAccessor<T> getPropertyAccessor(PersistentEntity<T,?> persistentEntity,
                                                      T instance)

Return a PersistentPropertyAccessor to access property values of the instance.

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.

readValue

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

Read a relational value into the desired destination type.

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.

writeValue

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

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

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.