org.springframework.data.neo4j.core.convert

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 and Description
<T> 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.
Object	readValue(org.neo4j.driver.Value source, TypeInformation<?> targetType, Function<org.neo4j.driver.Value,Object> conversionOverride) Reads a Value returned by the driver and converts it into a simple type supported by Neo4j SDN.
org.neo4j.driver.Value	writeValue(Object value, TypeInformation<?> sourceType, Function<Object,org.neo4j.driver.Value> conversionOverride) Converts an Object to a driver's value object.

Method Detail

convert

@Nullable
<T> 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
                           Function<org.neo4j.driver.Value,Object> 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
                                  Function<Object,org.neo4j.driver.Value> 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.

Returns:

A driver compatible value object.