问题
Here is my source object:
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<String,Object> meta;
}
Here is my destination object:
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;
}
And my mapper looks like the following:
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);
}
For now it works well but I would like to know if there is a more "elegant" way to set Map entries as source. Because with this I did not manage to add transformation functions using the "qualifiedByName" property, it looks like it can only work when a "source" is specified. Did I misunderstand something ?
I tried the following approaches without satisfying results :
- Overwrite getter for specific fields in my Record class
Add a transformation function with the "qualifiedByName" property. Something like:
@Named("metaGetter") default String dataGetter (String property) { return (String) r.meta.get(property); }
But obviously this does not compile as the property name is not valid as a proper source.
Thanks for your time.
回答1:
Write your own qualifier:
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<String, Object> in) {
return (String)in.get("ip");
}
@Server
public String server(Map<String, Object> in) {
return (String)in.get("server");
}
}
and then just add to the mapping:
@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 );
}
来源:https://stackoverflow.com/questions/44390808/mapstruct-dealing-with-hashmap-entries-as-source