Module io.helidon.common.mapper

Package io.helidon.common.mapper.spi

Interface MapperProvider

All Known Implementing Classes:

DbMapperProviderImpl

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface MapperProvider

Java Service loader service to get mappers.

Mapper provider provides mappers based on the source and target types and a qualifier. Generic mappers should always return MapperProvider.Support.COMPATIBLE, so specific mappers can be created for qualified usages. This is to support a different date/time mapper depending on usage. For this case we may have the following qualifiers (example, not normative): config,jdbc-oracle,http-header,http-query. Qualifiers should be defined by a constant in each component using mapping.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static final record	MapperProvider.ProviderResponse	Response of a provider.
static enum	MapperProvider.Support	How does this provider support the type.

Method Summary

Modifier and Type	Method	Description
default MapperProvider.ProviderResponse	mapper(GenericType<?> sourceType, GenericType<?> targetType, String qualifier)	Find a mapper that is capable of mapping from source to target types.
MapperProvider.ProviderResponse	mapper(Class<?> sourceClass, Class<?> targetClass, String qualifier)	Find a mapper that is capable of mapping from source to target classes.

Method Details

mapper

MapperProvider.ProviderResponse mapper(Class<?> sourceClass,
 Class<?> targetClass,
 String qualifier)

Find a mapper that is capable of mapping from source to target classes. Qualifiers are defined by each component using mapping. In case of clashing qualifiers, the first mapper that returns MapperProvider.Support.SUPPORTED will be chosen.

Parameters:

sourceClass - class of the source

targetClass - class of the target

qualifier - qualifiers of this mapping (such as config or http-headers, may be empty for default

Returns:

a mapper that is capable of mapping (or converting) sources to targets

mapper

default MapperProvider.ProviderResponse mapper(GenericType<?> sourceType,
 GenericType<?> targetType,
 String qualifier)

Find a mapper that is capable of mapping from source to target types. This method supports mapping to/from types that contain generics.

Parameters:

sourceType - generic type of the source

targetType - generic type of the target

qualifier - qualifier of the mapping - this is to allow multiple mappings for the same type depending on context such as HTTP Headers may use a different date mapping than database operations

Returns:

a mapper that is capable of mapping (or converting) sources to targets, default implementation calls mapper(Class, Class, java.lang.String) for types that are not generic, MapperProvider.ProviderResponse.unsupported() otherwise.