Package org.springframework.r2dbc.core

Class DataClassRowMapper<T>

java.lang.Object

org.springframework.r2dbc.core.BeanPropertyRowMapper<T>

org.springframework.r2dbc.core.DataClassRowMapper<T>

Type Parameters:

T - the result type

All Implemented Interfaces:

Function<Readable,T>

public class DataClassRowMapper<T>
extends BeanPropertyRowMapper<T>

Mapping Function implementation that converts an R2DBC Readable (a Row or OutParameters) into a new instance of the specified mapped target class. The mapped target class must be a top-level class or static nested class, and it may expose either a data class constructor with named parameters corresponding to column names or classic bean property setter methods with property names corresponding to column names (or even a combination of both).

The term "data class" applies to Java records, Kotlin data classes, and any class which has a constructor with named parameters that are intended to be mapped to corresponding column names.

When combining a data class constructor with setter methods, any property mapped successfully via a constructor argument will not be mapped additionally via a corresponding setter method. This means that constructor arguments take precedence over property setter methods.

Note that this class extends BeanPropertyRowMapper and can therefore serve as a common choice for any mapped target class, flexibly adapting to constructor style versus setter methods in the mapped class.

Please note that this class is designed to provide convenience rather than high performance. For best performance, consider using a custom readable mapping Function implementation.

Since:

6.1

Author:

Simon Baslé, Juergen Hoeller, Sam Brannen

Constructor Summary

Constructors

Constructor	Description
DataClassRowMapper(Class<T> mappedClass)	Create a new DataClassRowMapper.
DataClassRowMapper(Class<T> mappedClass, ConversionService conversionService)

Method Summary

Modifier and Type	Method	Description
protected T	constructMappedInstance(Readable readable, List<? extends ReadableMetadata> itemMetadatas, TypeConverter tc)	Construct an instance of the mapped class for the current Readable.

Methods inherited from class org.springframework.r2dbc.core.BeanPropertyRowMapper

apply, getItemValue, lowerCaseName, suppressProperty, underscoreName

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.function.Function

andThen, compose

Constructor Details

DataClassRowMapper

public DataClassRowMapper(Class<T> mappedClass)

Create a new DataClassRowMapper.

Parameters:

mappedClass - the class that each row should be mapped to

DataClassRowMapper

public DataClassRowMapper(Class<T> mappedClass,
 ConversionService conversionService)

Method Details

constructMappedInstance

protected T constructMappedInstance(Readable readable,
 List<? extends ReadableMetadata> itemMetadatas,
 TypeConverter tc)

Description copied from class: BeanPropertyRowMapper

Construct an instance of the mapped class for the current Readable.

The default implementation simply instantiates the mapped class. Can be overridden in subclasses.

Overrides:

constructMappedInstance in class BeanPropertyRowMapper<T>

Parameters:

readable - the Readable being mapped (a Row or OutParameters)

itemMetadatas - the list of item ReadableMetadata (either ColumnMetadata or OutParameterMetadata)

tc - a TypeConverter with this row mapper's conversion service

Returns:

a corresponding instance of the mapped class