Interface ResultReaderAttributeConverter<X,Y>

Type Parameters:

X - The entity value type

Y - The persisted value type (driver/native type)

All Superinterfaces:

AttributeConverter<X,Y>

@Indexed(ResultReaderAttributeConverter.class)
public interface ResultReaderAttributeConverter<X,Y>
extends AttributeConverter<X,Y>

ResultReader-aware attribute converter contract for SQL-like stores (JDBC/R2DBC).

Extends the generic AttributeConverter with a helper to read raw column values via a ResultReader. The returned raw value is then converted to the entity value using AttributeConverter.convertToEntityValue(Object, ConversionContext).

The ConversionContext may carry additional metadata and, when it is an instance of DatabaseTypeConversionContext, it exposes the database type associated with the current operation.

Implementations adapt between the entity-facing type X and the persisted driver type Y.

Since:

5.0.0

Author:

Nemanja Mikic

Method Summary

Modifier and Type	Method	Description
<R,I> @Nullable Object	readFromResultSet(DatabaseTypeConversionContext conversionContext, ResultReader<R,I> reader, R resultSet, I columnName)	Read a column value from a native result set via the provided converter-aware reader.

Methods inherited from interface AttributeConverter

convertToEntityValue, convertToPersistedValue

Method Details

readFromResultSet

<R,I> @Nullable Object readFromResultSet(DatabaseTypeConversionContext conversionContext,
 ResultReader<R,I> reader,
 R resultSet,
 I columnName)

Read a column value from a native result set via the provided converter-aware reader.

The returned value should be of the persisted type (Y) expected by AttributeConverter.convertToEntityValue(Object, ConversionContext).

The result set and column identifier types are tied to the reader generics.

Type Parameters:

R - The native result set type (e.g. java.sql.ResultSet or io.r2dbc.spi.Row)

I - The column identifier type expected by the reader (e.g. Integer index or String name)

Parameters:

conversionContext - the conversion context (may carry dialect and argument metadata)

reader - the converter-aware result reader for the underlying driver

resultSet - the native row/result set object (e.g. java.sql.ResultSet, R2DBC io.r2dbc.spi.Row, etc.)

columnName - the column identifier (index or name) as required by the reader

Returns:

the raw persisted value to be converted into the entity value, or null if the column is SQL NULL

Since:

5.0.0