嗨，我尝试从json更新问题表时遇到问题。 我需要从json将一些数据存储在db中。我使用多个实体来设置问题，并使用一些@onetomany来创建外键。
我第一次存储所有数据都很好，hibernate正确存储了自动生成的id的所有数据，当我尝试再次加载json子表上的某些更改时，Questionary的id正确存在（因为虽然我设置了值，但从json直接获取了一个字段）问题和答案更改ID。
我希望你能理解我的意思。
这是我的实体：
public class Questionary implements Serializable {
private static final long serialVersionUID = -6101283729971360969L;
/**
* Primary key from JSON
*/
@Id
@JsonIgnore
private int id;
@Version
private Long version;
private String desc;
@OneToMany(cascade=CascadeType.ALL)
@JoinColumn(name = "idQuest")
@OnDelete(action = OnDeleteAction.CASCADE)
@OrderBy("identityQuestion ASC")
private Set<Question> question;
public class Question implements Serializable {
private static final long serialVersionUID = -6101283729971360969L;
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private long id;
@Version
private Long version;
private int identityQuestion;
private String text;
private long idTipoTag;
@OneToMany(cascade=CascadeType.ALL)
@JoinColumn(name = "idQuestion")
@OnDelete(action = OnDeleteAction.CASCADE)
@OrderBy("identityAnswer ASC")
private Set<Answer> answer;
这是控制器上的方法
@RestController
@Slf4j
public class QuestionaryController {
@Autowired
private QuestionaryRepository questionaryRepository;
@Autowired
private AnswerRepository answerRepository;
@RequestMapping(value = "/save", method = RequestMethod.POST)
public void saveQuest(@RequestBody List<QuestionaryDTO> questDTO) {
for (QuestionaryDTO questionaryDTO : questDTO) {
/**
* find value in db
*/
Questionary quest = questionarioRepository.findById(questionarioDTO.getId());
if (quest != null) {
quest.setDescrizione(questionarioDTO.getDescrizione());
Set<QuestionDTO> listQuestion = QuestionaryDTO.getQuestion();
Set<Question> questionDB = quest.getQuestion();
ArrayList<QuestionDTO> l = new ArrayList<QuestionDTO>(listQuestion);
ArrayList<Question> c = new ArrayList<Question>(questionDB);
int i = -1;
for(int j=0; j<l.size();j++) {
i++;
Question dom = c.get(i);
dom.setIdentityQuestion(l.get(j).getId());
dom.setIdTipoTag(l.get(j).getIdTipoTag());
dom.setText(l.get(j).getText());
questionDB.add(dom);
ecc...
}
quest.setquestion(questionDB);
questionariyRepository.save(quest);
} else {
/**
* Questionary
*/
Questionary questn = new Questionary();
questn.setTitle(questionaryDTO.getTitle());
questn.setId(questionaryDTO.getId());
/**
* Questions
*/
Set<QuestionDTO> listQuestion = questionaryDTO.getQuestion();
Set<Question> QuestionDB = new HashSet<>();
for (QuestionDTO questionDTO : listQuest) {
Question que = new Question();
que.setIdentityQuestion(questionDTO.getId());
que.setText(QuestionDTO.getText());
que.setIdTipoTag(QuestionDTO.getIdTipoTag());
QuestionDB.add(que);
/**
* Answers
*/
Set<AnswerDTO> listAnswers = AnswerDTO.getAnswers();
Set<Answers> listAnswersDB = new HashSet<>();
for (AnswersDTO AnswersDTO : listAnswer) {
Answers ans = new Answers();
ans.setIdentityAnswer(AnswerDTO.getId());
asn.setText(AnswerDTO.getText());
listAnswersDB.add(ans);
}
dom.setAnswer(listAnswersDB);
}
questn.setQuestion(QuestionDB);
questionarioRepository.save(questn);
}
}
}
这是DTO实体
public class QuestionariyDTO implements Serializable{
private static final long serialVersionUID = -1886966747159529916L;
private int id;
private int identityQuestionary;
private String title;
private Set<QuestionDTO> questions;
}
public class QuestionDTO implements Serializable {
private static final long serialVersionUID = -1886966747159529916L;
private int id;
private String text;
private Long idTipoTag;
private Set<AnswerDTO> answers;
}
public class AnswerDTO implements Serializable{
private static final long serialVersionUID = -1886966747159529916L;
private Long id;
private String text;
private Long identityAnswer;
}
此为json结构示例
[
{
"id": 1,
"title": "TITLE",
"questions": [
{
"id": 1, <--- this id is only "identityQuestion" on db is not the primary key
"text": "some text",
"idTipoTag": 1,
"answers": [
{
"id": 1, <--- this id is only "identityAnswer" on db is not the primary key
"text": "answ 1"
},
{
"id": 2,
"text": "answ 2"
},
{
"id": 3,
"text": "answ 3"
},
{
"id": 4,
"text": "answ 4"
}
]
},
{
"id": 2,
"text": "some text",
"idTipoTag": 1,
"answers": [
...
.
.
.
.
.
]
},
...
]
}
]
很抱歉，很长的帖子。
编辑-解决方案：
随机保存的原因是HashSet，它们没有顺序，并且总是将日期保存在随机位置。
我刚刚将所有Set值都转换为List。完成后，当我去实例化对象时，我使用LinkedList作为订单值！
这项工作对我来说很生气！
这是一个示例：
之前：
Set<QuestionDTO> listQuestion = questionaryDTO.getQuestion();
Set<Question> QuestionDB = new HashSet<>();
之后：
List<QuestionDTO> listQuestion = questionaryDTO.getQuestion();
List<Question> QuestionDB = new LinkedList<>();
希望对某人来说这很用：）
答案 0 :(得分：0)
随机保存的原因是HashSet，它们没有顺序，并且总是将日期保存在随机位置。
我刚刚将所有Set值都转换为List。完成后，当我去实例化对象时，我使用LinkedList作为订单值！
这项工作对我来说很生气！
这是一个示例：
之前：
Set<QuestionDTO> listQuestion = questionaryDTO.getQuestion();
Set<Question> QuestionDB = new HashSet<>();
之后：
List<QuestionDTO> listQuestion = questionaryDTO.getQuestion();
List<Question> QuestionDB = new LinkedList<>();
希望对某人来说这很用：）