具有mapStruct的内部不可变类

Question

我们在MapStruct中使用不可变项，在将实体转换为dto时遇到问题。

@Value.Immutable
public interface ProjectDto {
    String getId();
    String getName();
    //ProjectStatisticsDto getStatistics();
}

@Value.Immutable
public interface ProjectStatisticsDto {
    Long getCount();
}

@Immutable
public interface Project extends Serializable {
    @JsonProperty("_id")
    String getId();
    String getName();
    //ProjectStatistics getStatistics();
}

@Immutable
public interface ProjectStatistics extends Serializable {
    Long getCount();
}

mapper类

@Mapper
public interface ProjectMapper {
    ProjectMapper INSTANCE = Mappers.getMapper(ProjectMapper.class);
    ImmProjectDto toDto(ImmProject project); // This works only when the inner model of project statistics is commented.
    //ProjectDto toDto(Project project); THIS DOES NOT WORK (Error 1)
    // ImmProjectDto toDto(ImmProject project); After I uncomment the inner class of project statistics then even this does not work (Error 2)

在出现错误的情况下，问题是完全相同的

Error 1: No implementation was created for ProjectMapper due to having a problem in the erroneous element com.xyz.ProjectDto. 
Error 2: No implementation was created for ProjectMapper due to having a problem in the erroneous element com.xyz.ProjectStatisticsDto. 

我检查了mapstruct与不可变的测试，没有什么不同https://github.com/mapstruct/mapstruct/blob/master/integrationtest/src/test/resources/immutablesBuilderTest/mapper/src/main/java/org/mapstruct/itest/immutables/Person.java.

我尝试删除序列化语句，但没有成功。我添加了一些冗长的声明

Note: MapStruct: Immutables found on classpath
Note: MapStruct: Using accessor naming strategy: org.mapstruct.ap.spi.ImmutablesAccessorNamingStrategy
Note: MapStruct: Using builder provider: org.mapstruct.ap.spi.ImmutablesBuilderProvider
Note: MapStruct: Using enum naming strategy: org.mapstruct.ap.spi.DefaultEnumMappingStrategy

这看起来绝对正确

Answer 1

看看问题“带mapStruct的内部不可变类”的标题，我猜您的不可变类位于另一个类中。

对于已经有PR的MapSTRt（参见mapstruct/mapstruct#2198）来说，这是一个已知的问题，它将在下一个非补丁版本中修复。

与此同时，您必须使您的不可变类成为顶级类。