Inheriting mapping definition

[twallmey]

Expected behavior

Hi all,
I've got a set of classes that (not directly) extend a common base class (XKBObject). For each class of this set I've defined a mapper. During mapping I would like to exclude a single property ("type") from the base class within all mappers.

For this reason I've defined a central MappeConfig that should exclude this single property:

@MapperConfig(
        componentModel = "spring",
        //build should fail if a target property is not mapped - in this case the mapping has to be defined manually
        unmappedTargetPolicy = ReportingPolicy.ERROR,
        mappingInheritanceStrategy = MappingInheritanceStrategy.AUTO_INHERIT_ALL_FROM_CONFIG
)
public interface MapstructConfig {
    @Mapping(target = "type", ignore = true)
        //for test purpose only
    XKBObject convert(XKBObject dto);
}

The configuration is referenced within all mappers:

@Mapper(
        config = MapstructConfig.class,
        componentModel = MappingConstants.ComponentModel.DEFAULT
)

I would expect that the mentioned "type"-Attribute is excluded from mapping.

Actual behavior

Unfortunately the property (type) is not excluded. Do you have any hints?

Steps to reproduce the problem

@MapperConfig(
        componentModel = "spring",
        //build should fail if a target property is not mapped - in this case the mapping has to be defined manually
        unmappedTargetPolicy = ReportingPolicy.ERROR,
        mappingInheritanceStrategy = MappingInheritanceStrategy.AUTO_INHERIT_ALL_FROM_CONFIG
)

MapStruct Version

1.5.5.Final

[thunderhook]

Hi @twallmey

Could you please try to narrow the problem down or provide more code?
I could not reproduce this with the following code:

import org.mapstruct.Mapper;
import org.mapstruct.MapperConfig;
import org.mapstruct.Mapping;
import org.mapstruct.MappingInheritanceStrategy;
import org.mapstruct.ReportingPolicy;


@MapperConfig(
    componentModel = "spring",
    //build should fail if a target property is not mapped - in this case the mapping has to be defined manually
    unmappedTargetPolicy = ReportingPolicy.ERROR,
    mappingInheritanceStrategy = MappingInheritanceStrategy.AUTO_INHERIT_ALL_FROM_CONFIG
)
interface Issue3611MapperConfig {

    @Mapping(target = "type", ignore = true)
    XKBObject convert(XKBObject dto);

}

@Mapper(config = Issue3611MapperConfig.class)
interface Issue3611Mapper {

    Target map(Source source);

}


class XKBObject {
    public String type;
}

class Source extends XKBObject {
    public String name;
}

class Target extends XKBObject {
    public String name;
}

It does not map type as expected:

@Generated(
    value = "org.mapstruct.ap.MappingProcessor",
    date = "2024-05-23T20:08:01+0200",
    comments = "version: 1.5.5.Final, compiler: javac, environment: Java 17.0.5 (Oracle Corporation)"
)
@Component
class Issue3611MapperImpl implements Issue3611Mapper {

    @Override
    public Target map(Source source) {
        if ( source == null ) {
            return null;
        }

        Target target = new Target();

        target.name = source.name;

        return target;
    }
}

After commenting out the mappingInheritanceStrategy it is getting mapped.

[twallmey]

Hi Oliver, thanks for your fast response. I’ve attached the relevant code that is currently defined for the conversion of a single/concrete object type (ProductGroup into ProductGroupV2 – both inherited from XKBObject). The corresponding mappers are attached as well. Unfortunately this code does still generate a mapping for the already mentioned attribute “type” although this should be ignored. Source-Code defined for mappers responsible for the conversion from ProductGroup tp ProductGroupV2 (and vice versa): ```java @Mapper( config = MapstructConfig.class, componentModel = MappingConstants.ComponentModel.DEFAULT ) public interface ProductGroupMapperPhysical extends VersionConvertable<ProductGroupV2, ProductGroup> { ProductGroupMapperPhysical INSTANCE = Mappers.getMapper(ProductGroupMapperPhysical.class); ; ProductGroup convert(ProductGroupV2 from, @context CycleAvoidingMappingContext context); @InheritInverseConfiguration ProductGroupV2 inverseConvert(ProductGroup from, @context CycleAvoidingMappingContext context); } ``` ```java public interface VersionConvertable<K extends XKBObject, V extends XKBObject> { V convert(K from, @context CycleAvoidingMappingContext context); K inverseConvert(V from, @context CycleAvoidingMappingContext context); } ``` ```java @MapperConfig( componentModel = "spring", //build should fail if a target property is not mapped - in this case the mapping has to be defined manually unmappedTargetPolicy = ReportingPolicy.ERROR, mappingInheritanceStrategy = MappingInheritanceStrategy.AUTO_INHERIT_ALL_FROM_CONFIG ) public interface MapstructConfig { @mapping(target = "type", ignore = true) //for test purpose only XKBObject convert(XKBObject dto); } ``` Source-Code for type hierarchy of ProductGroup: ```java @requiredargsconstructor public class ProductGroup extends SKBKnowledge { @Getter @Setter private String sapHierarchy; } ``` ```java public abstract class SKBKnowledge extends Knowledge { } ``` ```java public abstract class Knowledge extends XKBObject { @Getter @Setter private MultilingualString label; @Getter @Setter private Date modificationDate; @Getter @Setter private String comment; @Getter @Setter private MultilingualString description; } ``` ```java public abstract class XKBObject implements Serializable { @Getter @Setter @transient private URI type; @Getter @Setter @id private URI id; } ``` Source-Code of type hierarchy of ProductGroupV1: ```java @requiredargsconstructor public final class ProductGroupV2 extends VersionedKnowledge { @Getter @Setter private String sapHierarchy; @Getter @Setter private MultilingualString label; @Getter @Setter private Date modificationDate; @Getter @Setter private String comment; @Getter @Setter private MultilingualString description; @Getter @Setter private Set<URI> inferredTypes; } ``` ```java public abstract class VersionedKnowledge extends XKBObject { } ``` ```java public abstract class XKBObject implements Serializable { @Getter @Setter @transient private URI type; @Getter @Setter @id private URI id; } ``` The resulting/generated mapper implementation (excerpt) still contains the attribute “type” although it should be excluded (according to defined configuration): ```java @generated( value = "org.mapstruct.ap.MappingProcessor", date = "2024-05-24T08:00:08+0200", comments = "version: 1.5.5.Final, compiler: javac, environment: Java 17.0.9 (Amazon.com Inc.)" ) public class ProductGroupMapperPhysicalImpl implements ProductGroupMapperPhysical { @OverRide public ProductGroup convert(ProductGroupV2 from, CycleAvoidingMappingContext context) { ProductGroup target = context.getMappedInstance( from, ProductGroup.class ); if ( target != null ) { return target; } if ( from == null ) { return null; } ProductGroup productGroup = new ProductGroup(); context.storeMappedInstance( from, productGroup ); productGroup.setType( from.getType() ); productGroup.setId( from.getId() ); productGroup.setLabel( from.getLabel() ); productGroup.setModificationDate( from.getModificationDate() ); productGroup.setComment( from.getComment() ); productGroup.setDescription( from.getDescription() ); Set<URI> set = from.getInferredTypes(); if ( set != null ) { productGroup.setInferredTypes( new LinkedHashSet<URI>( set ) ); } productGroup.setSapHierarchy( from.getSapHierarchy() ); return productGroup; } @OverRide public ProductGroupV2 inverseConvert(ProductGroup from, CycleAvoidingMappingContext context) { ProductGroupV2 target = context.getMappedInstance( from, ProductGroupV2.class ); if ( target != null ) { return target; } if ( from == null ) { return null; } ProductGroupV2 productGroupV2 = new ProductGroupV2(); context.storeMappedInstance( from, productGroupV2 ); productGroupV2.setType( from.getType() ); productGroupV2.setId( from.getId() ); productGroupV2.setSapHierarchy( from.getSapHierarchy() ); productGroupV2.setLabel( from.getLabel() ); productGroupV2.setModificationDate( from.getModificationDate() ); productGroupV2.setComment( from.getComment() ); …. ``` I’m really looking forward to your response – as I do not have a clue what’s wrong. Best, Thorben

[thunderhook]

Just copying your code in a separate comment since github doesn't let me format your comment accordingly.

@Mapper(
        config = MapstructConfig.class,
        componentModel = MappingConstants.ComponentModel.DEFAULT
)
public interface ProductGroupMapperPhysical extends VersionConvertable<ProductGroupV2, ProductGroup> {
    ProductGroupMapperPhysical INSTANCE = Mappers.getMapper(ProductGroupMapperPhysical.class);
    ;

    ProductGroup convert(ProductGroupV2 from, @Context CycleAvoidingMappingContext context);

    @InheritInverseConfiguration
    ProductGroupV2 inverseConvert(ProductGroup from, @Context CycleAvoidingMappingContext context);
}

public interface VersionConvertable<K extends XKBObject, V extends XKBObject> {

    V convert(K from, @Context CycleAvoidingMappingContext context);

    K inverseConvert(V from, @Context CycleAvoidingMappingContext context);
}

@MapperConfig(
        componentModel = "spring",
        //build should fail if a target property is not mapped - in this case the mapping has to be defined manually
        unmappedTargetPolicy = ReportingPolicy.ERROR,
        mappingInheritanceStrategy = MappingInheritanceStrategy.AUTO_INHERIT_ALL_FROM_CONFIG
)
public interface MapstructConfig {

    @Mapping(target = "type", ignore = true)
        //for test purpose only
    XKBObject convert(XKBObject dto);
}

Source-Code for type hierarchy of ProductGroup:

@RequiredArgsConstructor
public class ProductGroup extends SKBKnowledge {

    @Getter
    @Setter
    private String sapHierarchy;
}

public abstract class SKBKnowledge extends Knowledge {
}

public abstract class Knowledge extends XKBObject {


    @Getter
    @Setter
    private MultilingualString label;

    @Getter
    @Setter
    private Date modificationDate;

    @Getter
    @Setter
    private String comment;

    @Getter
    @Setter
    private MultilingualString description;
}

public abstract class XKBObject implements Serializable {

    @Getter
    @Setter
    @Transient
    private URI type;

    @Getter
    @Setter
    @Id
    private URI id;
}

Source-Code of type hierarchy of ProductGroupV1:

@RequiredArgsConstructor
public final class ProductGroupV2 extends VersionedKnowledge {
    @Getter
    @Setter
    private String sapHierarchy;

    @Getter
    @Setter
    private MultilingualString label;

    @Getter
    @Setter
    private Date modificationDate;

    @Getter
    @Setter
    private String comment;

   @Getter
    @Setter
    private MultilingualString description;

    @Getter
    @Setter
    private Set<URI> inferredTypes;
}

public abstract class VersionedKnowledge extends XKBObject {
}

public abstract class XKBObject implements Serializable {

    @Getter
    @Setter
    @Transient
    private URI type;

    @Getter
    @Setter
    @Id
    private URI id;
}

The resulting/generated mapper implementation (excerpt) still contains the attribute “type” although it should be excluded (according to defined configuration):

@Generated(
    value = "org.mapstruct.ap.MappingProcessor",
    date = "2024-05-24T08:00:08+0200",
    comments = "version: 1.5.5.Final, compiler: javac, environment: Java 17.0.9 (Amazon.com Inc.)"
)
public class ProductGroupMapperPhysicalImpl implements ProductGroupMapperPhysical {

    @Override
    public ProductGroup convert(ProductGroupV2 from, CycleAvoidingMappingContext context) {
        ProductGroup target = context.getMappedInstance( from, ProductGroup.class );
        if ( target != null ) {
            return target;
        }

        if ( from == null ) {
            return null;
        }

        ProductGroup productGroup = new ProductGroup();

        context.storeMappedInstance( from, productGroup );

        productGroup.setType( from.getType() );
        productGroup.setId( from.getId() );
        productGroup.setLabel( from.getLabel() );
        productGroup.setModificationDate( from.getModificationDate() );
        productGroup.setComment( from.getComment() );
        productGroup.setDescription( from.getDescription() );
        Set<URI> set = from.getInferredTypes();
        if ( set != null ) {
            productGroup.setInferredTypes( new LinkedHashSet<URI>( set ) );
        }
        productGroup.setSapHierarchy( from.getSapHierarchy() );

        return productGroup;
    }

    @Override
    public ProductGroupV2 inverseConvert(ProductGroup from, CycleAvoidingMappingContext context) {
        ProductGroupV2 target = context.getMappedInstance( from, ProductGroupV2.class );
        if ( target != null ) {
            return target;
        }

        if ( from == null ) {
            return null;
        }

        ProductGroupV2 productGroupV2 = new ProductGroupV2();

        context.storeMappedInstance( from, productGroupV2 );

        productGroupV2.setType( from.getType() );
        productGroupV2.setId( from.getId() );
        productGroupV2.setSapHierarchy( from.getSapHierarchy() );
        productGroupV2.setLabel( from.getLabel() );
        productGroupV2.setModificationDate( from.getModificationDate() );
        productGroupV2.setComment( from.getComment() );

….

[twallmey]

After rebuilding the complete project I do get the following error right now:

Several matching inverse methods exist: convert(), convert(). Specify a name explicitly.

I assume the error results from the interface VersionConvertable that is implemented by ProductGroupMapperPhysical - in this case there is the method from the VersionConvertable interface and the overridden method from ProductGroupMapperPhysical. As far as I unterstand the error message I've to point to the correct method via attribute "name" of annotation. But how should I do this as both methods have the same name.

Any clues how to solve this inhertence problem? Or am I completely wrong?

[thunderhook]

Sorry, I haven't had time to reproduce this with the code you provided. Type parameter 'org.example._3611.ProductGroupV2' is not within its bound; should extend 'org.example._3611.XKBObject'

Perhaps you could try renaming some of your methods, e.g. from convert to convertProductGroup.

Please provide a minimal reproducible repository if you want us to look into this.

[twallmey]

Pls. excuse my delayed response. I've prepared a zip file that contains the relevant piece of code, only. We would like to avoid the bidirectional mapping of attribute "type". For this reason (and according to the mapstruct documentation) we have added a method to our mapstruct configuration that should skip this property for all matching object types (types extending XKBObject) .

mapstruct-fix.zip

Any hints and suggestions are warmly welcome!

Best,
Thorben

[thunderhook]

Thanks for the code, I've worked out a minimal reproducer. I don't have time to investigate it at the moment, so if anyone wants to have a look, feel free.

It seems that it can't distinguish between Target convert(Source from) and BaseClass convert(BaseClass dto). And a @Named annotation does not help either.

import java.net.URI;

import org.mapstruct.InheritInverseConfiguration;
import org.mapstruct.Mapper;
import org.mapstruct.MapperConfig;
import org.mapstruct.Mapping;
import org.mapstruct.MappingInheritanceStrategy;
import org.mapstruct.ReportingPolicy;

@Mapper(config = MapstructConfig.class)
interface Issue3611Mapper extends VersionConvertable<Source, Target> {
 
    @Mapping(target = "comment", constant = "irrelevant for this test")
    Target convert(Source from);

    // leads to: Several matching inverse methods exist: convert(), convert(). Specify a name explicitly.
    @InheritInverseConfiguration
    Source inverseConvert(Target from);

}

interface VersionConvertable<K extends BaseClass, V extends BaseClass> {

    V convert(K from);

    K inverseConvert(V from);

}

@MapperConfig(
    unmappedTargetPolicy = ReportingPolicy.ERROR,
    mappingInheritanceStrategy = MappingInheritanceStrategy.AUTO_INHERIT_FROM_CONFIG
)
interface MapstructConfig {

    @Mapping(target = "type", ignore = true)
    BaseClass convert(BaseClass dto);
}

abstract class BaseClass {
    public URI type;
    public URI id;
}

class Source extends BaseClass {
    public String sapHierarchy;
}

class Target extends BaseClass {
    public String sapHierarchy;
    public String comment;
}

[luxbe]

I would love to fix this issue. I will have a look in the coming days!

[luxbe]

A simple fix would be renaming the convert method in the BaseClass to something other than convert and specifying which that "convert" should be used with the @InheritInverseConfiguration:

package org.mapstruct.ap.test.bugs._3611;

import java.net.URI;

import org.mapstruct.InheritInverseConfiguration;
import org.mapstruct.Mapper;
import org.mapstruct.MapperConfig;
import org.mapstruct.Mapping;
import org.mapstruct.MappingInheritanceStrategy;
import org.mapstruct.ReportingPolicy;

@Mapper(config = MapstructConfig.class)
interface Issue3611Mapper extends VersionConvertable<Source, Target> {

    @Mapping(target = "comment", constant = "irrelevant for this test")
    Target convert(Source from);

    // leads to: Several matching inverse methods exist: convert(), convert(). Specify a name explicitly.
    @InheritInverseConfiguration(name = "convert")
    Source inverseConvert(Target from);

}

interface VersionConvertable<K extends BaseClass, V extends BaseClass> {

    V convert(K from);

    K inverseConvert(V from);

}

@MapperConfig(
    unmappedTargetPolicy = ReportingPolicy.ERROR,
    mappingInheritanceStrategy = MappingInheritanceStrategy.AUTO_INHERIT_FROM_CONFIG
)
interface MapstructConfig {

    @Mapping(target = "type", ignore = true)
    BaseClass baseConvert(BaseClass dto);
}

abstract class BaseClass {
    public URI type;
    public URI id;
}

class Source extends BaseClass {
    public String sapHierarchy;
}

class Target extends BaseClass {
    public String sapHierarchy;
    public String comment;
}

However, this workaround should not be necessary in my eyes. I will investigate further

[luxbe]

I managed to reproduce the same underlying issue without the complexity of inverse inheritance:

package org.mapstruct.ap.test.bugs._3611;

import org.mapstruct.InheritConfiguration;
import org.mapstruct.Mapper;
import org.mapstruct.MapperConfig;
import org.mapstruct.Mapping;
import org.mapstruct.MappingInheritanceStrategy;
import org.mapstruct.ReportingPolicy;

@Mapper(config = MapstructConfig.class)
interface Issue3611Mapper {
    // leads to: Several matching methods exist: convert(), baseConvert(). Specify a name explicitly
    @InheritConfiguration
    Target test(Source from);

    @Mapping(source = "attributeSource", target = "attributeTarget")
    Target convert(Source from);
}

@MapperConfig(
    unmappedTargetPolicy = ReportingPolicy.ERROR,
    mappingInheritanceStrategy = MappingInheritanceStrategy.AUTO_INHERIT_FROM_CONFIG
)
interface MapstructConfig {
    @Mapping(target = "attributeBase", ignore = true)
    BaseClass baseConvert(BaseClass dto);
}

// class details and attributes do not matter for this test
abstract class BaseClass {
    public String attributeBase;
}

class Source extends BaseClass {
    public String attributeSource;
}

class Target extends BaseClass {
    public String attributeTarget;
}

IMO this works as designed. Issue3611Mapper.test can inherit from both Issue3611Mapper.convert and MapstructConfig.baseConvert, so the user has to specify which one to choose with the name parameter.

This is the same behavior story as in the example before - Issue3611Mapper.inverseConvert can inherit from both the inverse of Issue3611Mapper.convert and the prototype method MapstructConfig.convert.

Maybe the role of prototype methods can be better explained in the docs of InheritInverseConfiguration, similar to the docs of InheritConfiguration:

... apply the configuration from another mapping method (declared on the same mapper type) or prototype method (declared on a mapper config class referenced via config ...

[filiphr]

Thanks @thunderhook and @luxbe for looking into this one.

I think that the inverse configuration is important for this and it should actually work properly. The Issue3611Mapper#convert already inherits the forward configuration, so I guess we need to be able to handle this properly automatically.

The fix might not be super trivial to fix though.

[tangyang9464]

Thanks @thunderhook and @luxbe for looking into this one.

I think that the inverse configuration is important for this and it should actually work properly. The Issue3611Mapper#convert already inherits the forward configuration, so I guess we need to be able to handle this properly automatically.

The fix might not be super trivial to fix though.

@filiphr As you expect, when there are multiple candidate methods for @InheritInverseConfiguration/@InheritInverseConfiguration, should we calculate whether there is an inheritance relationship between them and automatically select the one with the shortest distance, instead of directly reporting an error prompt and forcing the user to specify the name?