在Spring Rest控制器中获取JSON解析错误（MismatchedInputException）

Question

我对Spring很陌生。当我在Postman中尝试POST方法时，我遇到了一个JSON解析错误。基本上，我有一个类，我想以列表的形式调用另一个类。

@Entity
@Data
@EqualsAndHashCode(callSuper = true)
public class Tag extends AbstractEntity {

    @Column (nullable = false)
    private String tag;

@Entity
@Data
@EqualsAndHashCode(callSuper = true)
public class Question extends AbstractEntity {

    @Column (nullable = false)
    private String title;
    @Column (nullable = false)
    private String content;
    @OneToMany
    @Column (nullable = false)
    private List<Tag> tag;

以下是我的控制器：

@RestController
@RequestMapping("v1/enquiry")
public class EnquiryController {

    @Autowired
    private QuestionRepository questionRepository;

    @PostMapping
    public ResponseEntity<Question> createEnquiry(@RequestBody Question question) {
        if (question.getTitle() == null | question.getContent() == null) {
            throw new BadRequest("Please fill in the required fields!");
        }

        Question enq = questionRepository.save(question);
        return ResponseEntity.ok().body(enq);
    }

当我使用以下内容执行POST方法时：

{ 
   "title": "question",
   "content": "cogito",
   "tag": ["java", "rest"]
}

我得到以下错误。我尝试了所有的建议，类似的条件张贴在周围。都不起作用。我做错了什么？

{ 
   "title": "question",
   "content": "cogito",
   "tag": [{"tag":"java"},{"tag": "rest"}]
}

@Entity
@Data
@EqualsAndHashCode(callSuper = true)
public class Question extends AbstractEntity {

    @Column (nullable = false)
    private String title;
    @Column (nullable = false)
    private String content;
    @OneToMany(cascade = CascadeType.PERSIST)
    @Column (nullable = false)
    private List<Tag> tag;

Answer 1

请更改您的JSON结构。

{ "title": "question", "content": "cogito", "tag": [{"tag":"java"},{"tag": "rest"}] }

还要在映射中添加级联。

@OneToMany (cascade = CascadeType.ALL)
 @Column (nullable = false) 
 private List<Tag> tag;