MapStruct:将HashMap条目作为源处理

这是我的源对象:

public class Record {

    public final long captureTime;
    public final String environnement;
    public final String bundle;
    public final String type;
    public final String id;
    public final Map meta;

}

这是我的目标对象:

public class MappedRecord {

    public final long captureTime;
    public final String environnement;
    public final String bundle;
    public final String type;
    public final String id;
    public final String ip;
    public final String server;

}

我的映射器如下所示:

public interface RecordMapper {

    RecordMapper MAPPER = Mappers.getMapper( RecordMapper.class );


    @Mappings({
        @Mapping(source = "captureTime", target = "captureTime"),
        @Mapping(source = "environnement", target = "environnement"),
        @Mapping(source = "bundle", target = "bundle"),
        @Mapping(source = "type", target = "type"),
        @Mapping(source = "id", target = "id"),
        @Mapping(expression = "java((String) r.meta.get(\"ip\"))", target = "ip"),
        @Mapping(expression = "java((String) r.meta.get(\"server\"))", target = "server"),
    })

    MappedRecord toMappedRecord(Record r);

}

目前它运作良好,但我想知道是否有更"优雅"的方式将Map条目设置为源.因为有了这个,我没有设法使用"qualifiedByName"属性添加转换函数,看起来它只能在指定"source"时才能工作.我误解了什么吗？

我尝试了以下方法而没有令人满意的结果:

覆盖我的Record类中特定字段的getter

使用"qualifiedByName"属性添加转换函数.就像是:

@Named("metaGetter")
default String dataGetter (String property) {
    return (String) r.meta.get(property);
}

但显然这不会编译,因为属性名称无效作为正确的来源.

谢谢你的时间.

编写自己的限定符:

public class MappingUtil {
    @Qualifier
    @Target(ElementType.METHOD)
    @Retention(RetentionPolicy.SOURCE)
    public @interface Ip {
    }
    @Qualifier
    @Target(ElementType.METHOD)
    @Retention(RetentionPolicy.SOURCE)
    public static @interface Server {
    }
    @Ip
    public String ip(Map in) {

        return (String)in.get("ip");
    }
    @Server
    public String server(Map in) {

        return (String)in.get("server");
    }
}

然后只需添加到映射:

@Mapper( uses = MappingUtil.class )
public interface SourceTargetMapper {

    SourceTargetMapper MAPPER = Mappers.getMapper( SourceTargetMapper.class );

    @Mappings( {
        @Mapping(source = "map", target = "ip", qualifiedBy = MappingUtil.Ip.class ),
        @Mapping(source = "map", target = "server", qualifiedBy = MappingUtil.Server.class ),
    } )
    Target toTarget( Source s );
}