源参数中不存在名为“Id”的属性。你是说“空”吗？

Question

我有点陷入了错误之中

邮递班

@Data
@Getter
@Setter
@Entity
@Table(name = "posts", uniqueConstraints = { @UniqueConstraint(columnNames = { "title" }) }

)

public class Post {

    @Id
    @Column(name = "Id", nullable = false)
    private Long Id;

    @Column(name = "title", nullable = false)
    private String title;

    @Column(name = "description", nullable = false)
    private String description;

    @Column(name = "content", nullable = false)
    private String content;

    @OneToMany(mappedBy = "post", cascade = CascadeType.ALL, orphanRemoval = true)
    private Set<Comment> comments = new HashSet<>();

Comment.class

    Data
    @Entity
    @Table(name = "postcomment")
    public class Comment {
    
        @Id
        @Column(name = "Id", nullable = false)
        private Long Id;
    
        @Column(name = "remark", nullable = false)
        private String remark;
    
        @ManyToOne(fetch = FetchType.LAZY, optional = false) // get only related comments to post
        @JoinColumn(name = "post_Id", nullable = false)
        @OnDelete(action = OnDeleteAction.CASCADE)
        private Post post;
    }

PostDto。班

@Data
public class PostDto {

    private Long Id;

    @NotEmpty
    @Size(min = 2, message = "post title should have atleast 2 characters")
    private String title;

    @NotEmpty
    @Size(min = 10, message = "post title should have atleast 2 characters")
    private String description;

    @NotEmpty
    @Size(min = 10, message = "post title should have atleast 2 characters")
    private String content;

评论Dto.class

@Data
public class CommentDto {

    private Long Id;
    private String remark;


}

评论Mapper.class

@Mapper(imports = { Instant.class, DateTimeFormatter.class })
@Configuration
public interface CommentMapper {

    CommentMapper INSTANCE = Mappers.getMapper(CommentMapper.class);

    @Mapping(source = "Id", target = "Id")
    @Mapping(source = "remark", target = "remark")
    Comment getComment(CommentDto postDto);

    @Mapping(source = "Id", target = "Id")
    @Mapping(source = "remark", target = "remark")
    CommentDto getCommentDto(Comment post);

}

我试图解决它从过去的6小时，但仍然不明白为什么它显示我下面的错误

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project rest.api: Compilation failure: Compilation failure: 
[ERROR] /D:/work/rest.api/src/main/java/com/rest/api/mapper/CommentMapper.java:[22,17] No property named "Id" exists in source parameter(s). Did you mean "null"?
[ERROR] /D:/work/rest.api/src/main/java/com/rest/api/mapper/CommentMapper.java:[22,17] No property named "remark" exists in source parameter(s). Did you mean "null"?
[ERROR] /D:/work/rest.api/src/main/java/com/rest/api/mapper/CommentMapper.java:[26,20] No property named "Id" exists in source parameter(s). Did you mean "null"?
[ERROR] /D:/work/rest.api/src/main/java/com/rest/api/mapper/CommentMapper.java:[26,20] No property named "remark" exists in source parameter(s). Did you mean "null"?

任何有用的建议都是解决这个问题的希望。

第二，当需要所有的getter和setter时，只有@数据可以吗？




Answer 1

出现错误的原因是："源参数中不存在名为"Id"的属性。你是说“无效”吗？"是由于属性名称Id不存在。

很可能您有一个getter/setter，看起来像getId（）和setId（String Id）。

这意味着从MapStruct的角度来看，属性的名称是id。MapStruct不查看私有字段，它根据getter/setter而不是字段来检测属性。