在JSON中序列化时，JHipster实体的用户属性设置为null

Question

I'm not a huge expert of Spring Boot, and a beginner with JHipster

My entity is :

@Entity
@Table(name = "meal")
public class Meal implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;


    @ManyToOne(fetch = FetchType.EAGER) // added this to JHipster generation
    @JsonIgnoreProperties("meals")
    private User user;

    // ...
}

I don't think the fetch eager is needed, as it's eager by default I guess. I also tried with or without @JsonIgnoreProperties

I didn't touch the GET /api/meals resource

    @GetMapping("/meals")
    public ResponseEntity<List<Meal>> getAllMeals(Pageable pageable, @RequestParam MultiValueMap<String, String> queryParams, UriComponentsBuilder uriBuilder) {
        Page<Meal> page = mealService.findAll(pageable);
        HttpHeaders headers = PaginationUtil.generatePaginationHttpHeaders(uriBuilder.queryParams(queryParams), page);
        return ResponseEntity.ok().headers(headers).body(page.getContent());
    }

nor service:

    @Transactional(readOnly = true)
    public Page<Meal> findAll(Pageable pageable) {
        log.debug("Request to get all Meals");
        return mealRepository.findAll(pageable);
    }

And I get this JSON:

[ {
  "id" : 1,
  "instant" : "2019-06-20T03:59:53Z",
  "user" : null
}, {
  "id" : 2,
  "instant" : "2019-06-20T04:18:47Z",
  "user" : null
}]

Answer 1

Actually the database file meals.csv loaded by liquibase had no user column.

I've update the meals.csv file

id;instant;text;user_id
1;2019-06-20T03:59:53;My own value;4
2;2019-06-20T04:18:47;And another meal;4

Updated manually the changeset by finding loadData (might not be the best practice !)

<changeSet id="20190620074431-1-data" author="jhipster" context="faker">
        <loadData
                  file="config/liquibase/data/meal.csv"
                  separator=";"
                  tableName="meal">
            <column name="id" type="numeric"/>
            <column name="instant" type="datetime"/>
            <column name="text" type="string"/>
            <column name="user_id" type="numeric"/> <!-- <<< Added this -->
        </loadData>
</changeSet>

then ran ./mvnw clean and relaunched the app.

This worked for me and seems logical but I wonder why foreign keys are not randomly generated.