Package org.springframework.data.convert

Interface PropertyValueConverter<DV,SV,C extends ValueConversionContext<? extends PersistentProperty<?>>>

Type Parameters:

DV - domain-specific type.

SV - store-native type.

C - the store specific conversion context.

All Known Implementing Classes:

PropertyValueConverter.FunctionPropertyValueConverter, PropertyValueConverter.ObjectToObjectPropertyValueConverter

public interface PropertyValueConverter<DV,SV,C extends ValueConversionContext<? extends PersistentProperty<?>>>

PropertyValueConverter provides a symmetric way of converting certain properties from domain to store-specific values.

A PropertyValueConverter is, other than a ReadingConverter or WritingConverter, only applied to special annotated fields which allows a fine-grained conversion of certain values within a specific context.

Converter methods are called with non-null values only and provide specific hooks for null value handling. readNull(ValueConversionContext) and writeNull(ValueConversionContext) methods are specifically designated to either retain null values or return a different value to indicate null values.

Since:

2.7

Author:

Christoph Strobl, Mark Paluch

See Also:

• ValueConversionContext
• PersistentProperty

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	PropertyValueConverter.FunctionPropertyValueConverter<DV,SV,P extends PersistentProperty<P>>	A PropertyValueConverter that delegates conversion to the given BiFunctions.
static enum	PropertyValueConverter.ObjectToObjectPropertyValueConverter	No-op PropertyValueConverter implementation.

Method Summary

Modifier and Type	Method	Description
DV	read(SV value, C context)	Convert the given store specific value into it's domain value representation.
default DV	readNull(C context)	Convert the given null value from the store into its domain value representation.
SV	write(DV value, C context)	Convert the given domain-specific value into it's native store representation.
default SV	writeNull(C context)	Convert the given null value from the domain model into it's native store representation.

Method Details

read

@Nullable
DV read(SV value,
 C context)

Convert the given store specific value into it's domain value representation. Typically, a read operation.

Parameters:

value - value to read.

context - ValueConversionContext containing store-specific metadata used in the value conversion; never null.

Returns:

the converted value. Can be null.

readNull

@Nullable
default DV readNull(C context)

Convert the given null value from the store into its domain value representation. Typically, a read operation. Returns null by default.

Parameters:

context - ValueConversionContext containing store-specific metadata used in the value conversion; never null.

Returns:

the converted value. Can be null.

write

@Nullable
SV write(DV value,
 C context)

Convert the given domain-specific value into it's native store representation. Typically, a write operation.

Parameters:

value - value to write; can be null.

context - ValueConversionContext containing store-specific metadata used in the value conversion; never null.

Returns:

the converted value. Can be null.

writeNull

@Nullable
default SV writeNull(C context)

Convert the given null value from the domain model into it's native store representation. Typically, a write operation. Returns null by default.

Parameters:

context - ValueConversionContext containing store-specific metadata used in the value conversion; never null.

Returns:

the converted value. Can be null.