Bugs

• Redundant if condition in Java record mapping with RETURN_DEFAULT strategy (#3747)
• Stackoverflow with Immutables custom builder (#3370)
• Unused import of java.time.LocalDate when mapping source LocalDateTime to target LocalDate (#3732)

Documentation

• Add section to README.md comparing mapstruct with Java Records (#3751)

Bugs

• Regression from 1.6.1: ClassCastException when using records (#3717)

Enhancements

• Use Java LinkedHashSet and LinkedHashMap new factory method with known capacity when on Java 19 or later (#3113)

Bugs

• Inverse Inheritance Strategy not working for ignored mappings only with target (#3652)
• Inconsistent ambiguous mapping method error when using SubclassMapping: generic vs raw types (#3668)
• Fix regression when using InheritInverseConfiguration with nested target properties and reversing target = "." (#3670)
• Deep mapping with multiple mappings broken in 1.6.0 (#3667)
• Two different constants are ignored in 1.6.0 (#3673)
• Inconsistent ambiguous mapping method error: generic vs raw types in 1.6.0 (#3668)
• Fix cross module records with interfaces not recognizing accessors (#3661)
• @AfterMapping methods are called twice when using target with builder (#3678)
• Compile error when using @AfterMapping method with Builder and TargetObject (#3703)

Behaviour change

Inverse Inheritance Strategy not working for ignored mappings only with target

Prior to this fix @Mapping(target = "myProperty", ignore = true) was being ignored when using @InheritInverseConfiguration.

e.g.

@Mapper
public interface ModelMapper {

    @Mapping(target = "creationDate", ignore = true)
    Entity toEntity(Model model);    

    @InheritInverseConfiguration
    Model toModel(Entity entity);
}

In the example above prior 1.6.1 the Model toModel(Entity entity) was going to map the id property. In order to keep that behavior you'll need to explicitly do the mapping for it.

@Mapper
public interface ModelMappe {
    @Mapping(target = "creationDate", ignore = true) // NOTE: Handled by JPA.
    Entity toEntity(Model model);    

    @InheritInverseConfiguration
    @Mapping(target = "creationDate", source = "creationDate") // Allow reading from Entity
    Model toModel(Entity entity);
}

Previous Release Notes

• 1.6.0.RC1
• 1.6.0.Beta2
• 1.6.0.Beta1

Enhancements

• Breaking change: (#3574) -
  This reverts #2560, because we've decided that @BeanMapping(ignoreByDefault = true) should only be applied to target properties and not to source properties.
  Source properties are ignored anyway, the BeanMapping#unmappedSourcePolicy should be used to control what should happen with unmapped source policy

Bugs

• Breaking change: Presence check method used only once when multiple source parameters are provided (#3601)
• Fix @SubclassMapping not working with @BeanMapping#ignoreUnmappedSourceProperties (#3609)
• Fix duplicate method generation with recursive auto mapping (#3591)

Documentation

• Fix documentation of unmappedSourcePolicy default value (#3635)
• Fix documentation link of before and after mapping when using builders (#3639)
• Fix typo in experimental note (#3634)
• Add example classes for the passing target type documentation (#3504)

Build

• Enforce whitespaces around the for colon with CheckStyle (#3642)

Breaking changes

Presence checks for source parameters

In 1.6, support for presence checks on source parameters has been added.
This means that even if you want to map a source parameter directly to some target property the new @SourceParameterCondition or @Condition(appliesTo = ConditionStrategy.SOURCE_PARAMETERS) should be used.

e.g.

If we had the following in 1.5:

@Mapper
public interface OrderMapper {

    @Mapping(source = "dto", target = "customer", conditionQualifiedByName = "mapCustomerFromOrder")
    Order map(OrderDTO dto);

    @Condition
    @Named("mapCustomerFromOrder")
    default boolean mapCustomerFromOrder(OrderDTO dto) {
        return dto != null && dto.getCustomerName() != null;
    }

}

Then MapStruct would generate

public class OrderMapperImpl implements OrderMapper {

    @Override
    public Order map(OrderDTO dto) {
        if ( dto == null ) {
            return null;
        }

        Order order = new Order();

        if ( mapCustomerFromOrder( dto ) ) {
            order.setCustomer( orderDtoToCustomer( orderDTO ) );
        }

        return order;
    }
}

In order for the same to be generated in 1.6, the mapper needs to look like this:

@Mapper
public interface OrderMapper {

    @Mapping(source = "dto", target = "customer", conditionQualifiedByName = "mapCustomerFromOrder")
    Order map(OrderDTO dto);

    @SourceParameterCondition
    @Named("mapCustomerFromOrder")
    default boolean mapCustomerFromOrder(OrderDTO dto) {
        return dto != null && dto.getCustomerName() != null;
    }

}

Features

• Support conditional mapping for source parameters (#2610, #3459, #3270)
• Add @SourcePropertyName to handle a property name of the source object (#3323) - Currently only applicable for @Condition methods

Enhancements

• Improve error message for mapping to target = "." using expression (#3485)
• Improve error messages for auto generated mappings (#2788)
• Remove unnecessary casts to long (#3400)

Bugs

• @Condition cannot be used only with @Context parameters (#3561)
• @Condition treated as ambiguous mapping for methods returning Boolean/boolean (#3565)
• Subclass mapping warns about unmapped property that is mapped in referenced mapper (#3360)
• Interface inherited build method is not found (#3463)
• Bean with getter returning Stream is treating the Stream as an alternative setter (#3462)
• Using Mapping#expression and Mapping#conditionalQualifiedBy(Name) should lead to compile error (#3413)
• Defined mappings for subclass mappings with runtime exception subclass exhaustive strategy not working if result type is abstract class (#3331)

Documentation

• Clarify that Mapping#ignoreByDefault is inherited in nested mappings in documentation (#3577)

Build

• Improve tests to show that Lombok @SuperBuilder is supported (#3524)
• Add Java 21 CI matrix build (#3473)

Features

• Access to target property name (#2688) - @TargetPropertyName can be used to access the target property name to conditional and mapping methods
• Support passing annotations to generated code (#1574, #2773, #2895, #2983) - Using @AnnotateWith. If a method is annotated with @Deprecated it is automatically copied into the generated code.
• Support for globally defining nullValueIterableMappingStrategy and nullValueMapMappingStrategy (#2953) - The different strategies can be configured using mapstruct.nullValueIterableMappingStrategy and mapstruct.nullValueMapMappingStrategy respectively
• Support qualifiers for SubclassMapping annotated methods (#3119)
• Support defining custom processor options for custom SPI (#3071) - There is also AdditionalSupportedOptionsProvider that can be used to defined the supported options for a custom SPI. The additional options cannot start with mapstruct.
• Support for defining Javadoc on the generated mapper (#2987) - Using @Javadoc

Enhancements

• Support for converting between Enum and Integer (#2963)
• Support for converting between Locale and String (#3172)
• Support for implicit conversion between java.time.LocalDate and java.time.LocalDateTime (#3199)
• Support custom name in Spring annotations (#1427) - Can be done using @AnnotateWith(value = Service.class, elements = @AnnotateWith.Element(strings = "cakeMapperV2"))
• Support meta annotations for @ValueMapping (#3037)
• Ambiguous mapping method but there is a more specific mapping (#1216)
• Do not treat getter as an alternative write accessor when using CollectionMappingStrategy#TARGET_IMMUTABLE (#2952)
• Improve line location report for invalid qualifier for SubclassMapping (#3202)
• Support @InheritConfiguration for @SubclassMapping in methods with identical signature (#3125)
• Do not require subclassExhaustiveStrategy when source is a sealed class and all subtypes are specified (#3054)
• Add validation of String type for @TargetPropertyName (#2863)
• Support for all lifecycle methods on type being build with builders (#1454)
  • @BeforeMapping with @TargetType the type being build
  • @AfterMapping with @TargetType the type being build
  • @AfterMapping with @MappingTarget the type being build
• Redundant null checks for nested properties (#3245)
• @Default on Java Record's constructor isn't respected (#3231)
• Add InjectionStrategy.SETTER (#3229)
• Add BeanMapping#unmappedSourcePolicy (#3309)
• Improve support for Map attributes for immutables (#3089)
• Support mapping Iterable to Collection (#3376)

Bugs

• Breaking change: Mapping from Map to Bean (#3144)
• Condition with @TargetType on Collection fails to compile (#2901)
• Annotations are automatically passed in forged methods (#3015)
• Mapping Composition does not work for @SubclassMapping (#3174)
• Mapping control disabling conversions does not disable them in 2 step mappings (#3186)
• @BeanMapping(ignoreByDefault = true) does not work for constructor properties (#3158)
• @ValueMapping strips spaces from source (#3153)
• defaultExpression does not work when mapping a collection of custom types (#3159)
• Arrays cannot be mapped to collection / iterable using an adder method (#3165)
• Unmapped source properties error when source is mapped to a nested field of the target object (#2781)
• NullPointerException when ignoring target '.' (#3238) - There is now a compilation error instead of an error in the processor
• NullValuePropertyMappingStrategy.IGNORE does not ignore target collection even when source one is null (only when collectionMappingStrategy = CollectionMappingStrategy.TARGET_IMMUTABLE) (#3104)
• @SubclassMapping not working with @Mapping nested properties and target all (#3126)
• Compile error when using default and static methods in @MapperConfig (#3296)
• Generic class with adder method and CollectionMappingStrategy.ADDER_PREFERRED fails (#3310)
• MapStruct can not map only primitives (#3317)
• 2-step mapping with generics does not work correctly (#2663)
• MapStruct no longer handles generic mapping methods (in conjunction with immutables) after upgrading from 1.4.x to version 1.5.x (#3163)
• Ignored mappings when using @InheritConfiguration (#3361)

Documentation

• Use GitHub new Issue Form Templates (#3008)
• Mapping composition is no longer experimental (#3239)
• Improve Lombok integration documentation (#3374)

Build / Refactoring

• Try to stabilise some date conversion tests (#2806)
• Avoid unnecessary unboxing of Boolean (#3003)
• Update FreeMarker to 2.3.32
• Refactor method selection and use a context to be able to more easily access information (#3280)
• Update tarLongFileMode to use POSIX (#3340)
• Simplified some expressions, redundant expressions removed (#3292)
• Refactor to use presence check for mapping methods (#3347) - Still only internal and custom presence checks methods are not supported for source parameters (see #2610 for that)
• Update github actions (#3397)
  • Add Java 21 to test matrix
  • Add Java EA to test matrix
  • Removing java 13 and 18 from test matrict

Breaking Changes

Map to Bean

In 1.5 we added support for mapping a map to a bean by implicitly mapping all the properties from the target bean by accessing them from the map. However, this lead to some problems in multi mapping methods. Therefore, in this release we tightened up a bit and in multi source mapping methods the Map will not be considered when doing implicit mappings.

e.g.

@Mapper
public interface CarMapper {

    // This method is going to implicitly map all the target properties from the map
    Target map(Map<String, Object> map);
    
    // This method is not going to use the map for implicit mappings.
    //  Only the name will be mapped from the map (since it has been defined like that
    @Mapping(target = "name", source = "map.name")
    Target map(Source source, Map<String, Object> map)

}

@BeanMapping inheritance

All, except resultType and ignoredUnmappedSourceProperties attributes of @BeanMapping have been made to consistently be passed down to the generated nested methods. This means that if you were relying on some buggy behavior it might no longer work.

e.g. BeanMapping#ignoreByDefault was not being passed down properly, i.e. implicit mapping was being done for nested properties. This has been fixed. If you want to implicitly map nested mappings then you'll have to define your own mapper appropriatelly.

@Mapper
interface MyMapper {
  @BeanMapping( ignoreByDefault = true )
  @Mapping( source = "sub", target = "target" )
  Target map( Source source );
}

needs to be replaced with

@Mapper
interface MyMapper {
  @BeanMapping( ignoreByDefault = true )
  @Mapping( source = "sub", target = "target" )
  Target map( Source source );
  
  // this is the mapping `source = "sub"` and `target = "target"` 
  // redefined to get rid of the `ignoreByDefault=true`, because this property is inherited
  SubTarget subSourceToSubTarget( SubSource subSource );
}

Sponsoring

After the request from the community we have enabled sponsoring for the project. See #2340 for how you can sponsor us if you want to.

Contributors

• @anton-erofeev
• @Blackbaud-JasonBodnar
• @Bragolgirith
• @chenzijia12300
• @eroznik
• @EvaristeGalois11
• @ivlcic
• @jccampanero
• @kooixh
• @MengxingYuan
• @MLNW
• @Nikolas-Charalambidis
• @paparadva
• @prasanth08
• @ro0sterjam
• @rgdoliveira
• @venkatesh2090

Enhancements

• Add support for Jakarta XML Binding (#2730)

Bugs

• BeanMappingOptions#ignoreUnmappedSourceProperties are not inherited via @InheritConfiguration (#3248) - Regression from 1.5.3

Documentation

• jakarta-cdi component model not in docs (#3236)
• Polish links in docs (#3214)

Enhancements

• Support for Jakarta @ApplicationScoped is missing (#2950)

Bugs

• Exceptions declared to be thrown by a mapping method, are not declared in generated mapping methods for nested types (#3142)
• DeepClone mapping control not generating third tier functions to clone (#3135)
• missing throws clauses when mapping enum with checked exceptions (#3110)
• Version 1.5.3 doesn't consider Mapping annotations for nested objects (worked with 1.5.2) (#3057)
• Cannot use only BeanMapping#mappingControl (#3040)

Documentation

• Document <THROW_EXCEPTION> in the reference guide (#3112)

Bugs

• Generic @AfterMapping does not consider @MappingTarget properly in 1.5 (#3036)
• Method annotated with @AfterMapping is not called (#2955)
• Ignored unknown source property error, but property exist (#2743)
• SubclassMapping doesn't honour mappingControl (#3018)
• Upgrade from 1.4.1 to 1.5.2 broke primitive to wrapper classes mapping (#2921)
• Conversion of BigDecimal to primitive double wrong with 1.5.2 (#2913)
• Ambiguous mapping methods when upgrading to MapStruct 1.5.0.RC1 (#2840)
• SubclassMapping stackoverflow exception (#2825)
• Optional wrapping pattern broken in 1.5.2.Final (#2925)
• Missing import in generated mapper when referencing a nested enum from an unrelated class (#2945)
• Unused import warning of nested classes (#2907)
• Compilation error in generated code for @Conditional and collection (#2937)
• Missing import of nested class (#2897)
• Ignoring unmapped source properties in inverse inheritance (#2949)
• Compilation error when mapping fields with the same type due to not wrapping in a try-catch block (#2839)
• Using @TargetType as a parameter for @Condition causes NPE during compiling (#2882)
• Cannot map from a covariant (extends) generic type (#2677)

Documentation

• Add IntelliJ and Eclipse plugin to the documentation (#2928)
• Fix typos in documentation (#2974, #2982, #2989)
• Update Typos in javadoc (#2958)
• Polish comments, javadoc and documentation (#3026)
• Improve documentation for BeanMapping#ignoreByDefault (#2929)

Build

• Build fails when running mvn test on an M1 Mac (#2922)