Interface Neo4jConversionService

@API(status=STABLE,
     since="6.0")
public interface Neo4jConversionService

This service orchestrates a standard Spring conversion service with Neo4jConversions registered. It provides simple delegating functions that allow for an override of the converter being used.

Since:

6.0

Author:

Michael J. Simons

Method Summary

Modifier and Type	Method	Description
<T> @Nullable T	convert(Object source, Class<T> targetType)	Delegates to the underlying service, without the possibility to run a custom conversion.
boolean	hasCustomWriteTarget(Class<?> sourceType)	Returns whether we have a custom conversion registered to read sourceType into a native type.
boolean	isSimpleType(Class<?> type)	Return true if the given class represents a Neo4j simple type.
@Nullable Object	readValue(@Nullable org.neo4j.driver.Value source, TypeInformation<?> targetType, @Nullable Neo4jPersistentPropertyConverter<?> conversionOverride)	Reads a Value returned by the driver and converts it into a simple type supported by Neo4j SDN.
org.neo4j.driver.Value	writeValue(@Nullable Object value, TypeInformation<?> sourceType, @Nullable Neo4jPersistentPropertyConverter<?> conversionOverride)	Converts an Object to a driver's value object.

Method Details

convert

<T> @Nullable T convert(Object source,
 Class<T> targetType)

Delegates to the underlying service, without the possibility to run a custom conversion.

Type Parameters:

T - the type to be returned

Parameters:

source - the source to be converted

targetType - the target type

Returns:

the converted value

hasCustomWriteTarget

boolean hasCustomWriteTarget(Class<?> sourceType)

Returns whether we have a custom conversion registered to read sourceType into a native type. The returned type might be a subclass of the given expected type though.

Parameters:

sourceType - must not be null

Returns:

true if a custom write target exists.

See Also:

• CustomConversions.hasCustomWriteTarget(Class)

readValue

@Nullable Object readValue(@Nullable org.neo4j.driver.Value source,
 TypeInformation<?> targetType,
 @Nullable Neo4jPersistentPropertyConverter<?> conversionOverride)

Reads a Value returned by the driver and converts it into a simple type supported by Neo4j SDN. If the value cannot be converted, a TypeMismatchDataAccessException will be thrown, it's cause indicating the failed conversion.

The returned object is generic as this method will take create target collections in case the incoming value describes a collection.

Parameters:

source - the value to be read, may be null.

targetType - the type information describing the target type.

conversionOverride - an optional conversion override.

Returns:

a simple type or null, if the value was null or Values.NULL.

Throws:

TypeMismatchDataAccessException - in case the value cannot be converted to the target type

writeValue

org.neo4j.driver.Value writeValue(@Nullable Object value,
 TypeInformation<?> sourceType,
 @Nullable Neo4jPersistentPropertyConverter<?> conversionOverride)

Converts an Object to a driver's value object.

Parameters:

value - the value to get written, may be null.

sourceType - the type information describing the target type.

conversionOverride - a conversion overriding the default

Returns:

a driver compatible value object.

isSimpleType

boolean isSimpleType(Class<?> type)

Return true if the given class represents a Neo4j simple type.

Parameters:

type - a type that should be checked whether it's simple or not

Returns:

true if type is a simple type, according to Neo4jSimpleTypes and the registered converters.