I have a DTO like this
@Data
public class MessageDTO implements Serializable {
private Long id;
}
and an entity
@Entity
@Data
public class Message implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Long id;
@Column(name = "timestamp")
private Instant timestamp;
}
I want to create a mapper to map DTO to entity. How can I make the field private Instant timestamp;
has value like Instant.now()?
My mapper so far
@Mapper(componentModel = "spring", imports = Instant.class)
public interface MessageMapper extends EntityMapper<MessageDTO, Message> {
@Override
@Mapping(target = "timestamp", source = "" ,defaultExpression = "java(Instant.now())")
Message toEntity(MessageDTO dto);
}
It got compile error
Compilation failure
[ERROR] /D:/Shared/projects/IdeaProjects/medical/src/main/java/io/medical/service/mapper/MessageMapper.java:[22,45] No property named "" exists in source parameter(s)
CodePudding user response:
The issue is due to the source
being empty. Remove the source
and use expression
instead of defaultExpression
.
@Mapper(componentModel = "spring")
public interface MessageMapper extends EntityMapper<MessageDTO, Message> {
@Override
@Mapping(target = "timestamp", expression = "java(Instant.now())")
Message toEntity(MessageDTO dto);
}
When there is a source but the source is null upon resolving, then defaultExpression
comes handy to assign a value to the target.