英文:
Spring jpa ManyToOne findAll does not return the second record that has the same @ManyToOne attribute
问题
[{"permanentCode": "FEST120412001","firstName": "TEST","lastName": "FEST","gender": "Female","dateOfBirth": "12-04-2012","legalTutors": [],"classroom": {"id": "P1A","year": 1,"section": "A","cycle": 1,"campus": "PRIMARY","students": [{"permanentCode": "TEST211114001","firstName": "TEST","lastName": "TEST","gender": "Male","dateOfBirth": "21-11-2014","legalTutors": [],"classroom": "P1A"},"FEST120412001"]}},{"permanentCode": "TEST211114001","firstName": "TEST","lastName": "TEST","gender": "Male","dateOfBirth": "21-11-2014","legalTutors": [],"classroom": {"id": "P1A","year": 1,"section": "A","cycle": 1,"campus": "PRIMARY","students": [{"permanentCode": "FEST120211001","firstName": "TEST","lastName": "FEST","gender": "Female","dateOfBirth": "12-02-2011","legalTutors": [],"classroom": "P1A"},"FEST120412001"]}}]
英文:
I am using spring jpa and I have the following class:
@Entity@Table(name = "student")@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})@JsonIdentityInfo( generator = ObjectIdGenerators.PropertyGenerator.class, property = "permanentCode")public class Student implements Serializable {@Idprivate String permanentCode;....@ManyToOne(fetch = FetchType.LAZY)@JoinColumn(name="classroom_id")private Classroom classroom;
And the other class is:
@Entity@Table(name = "classroom")@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})@JsonIdentityInfo( generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")public class Classroom implements Serializable {@Idprivate String id;...@OneToMany(mappedBy = "classroom", fetch = FetchType.LAZY, cascade = CascadeType.ALL)private Set<Student> students;
When I try to get all the students in postman from my database with:
public List<Student> getAllStudents() {return studentRepository.findAll();}
I get only the permanentCode TEST120211001 of the second record that has the same classroom, without any other details, as shown below:
[{"permanentCode": "FEST120412001","firstName": "TEST","lastName": "FEST","gender": "Female","dateOfBirth": "12-04-2012","legalTutors": [],"classroom": {"id": "P1A","year": 1,"section": "A","cycle": 1,"campus": "PRIMARY","students": [{"permanentCode": "TEST120211001","firstName": "TEST","lastName": "TEST","gender": "Male","dateOfBirth": "12-02-2011","legalTutors": [],"classroom": "P1A"},"FEST120412001"]}},"TEST120211001"]
What I want instead is something like:
[{"permanentCode": "FEST120412001","firstName": "TEST","lastName": "FEST","gender": "Female","dateOfBirth": "12-04-2012","legalTutors": [],"classroom": {"id": "P1A","year": 1,"section": "A","cycle": 1,"campus": "PRIMARY","students": [{"permanentCode": "TEST211114001","firstName": "TEST","lastName": "TEST","gender": "Male","dateOfBirth": "21-11-2014","legalTutors": [],"classroom": "P1A"},"FEST120412001"]}},{"permanentCode": "TEST211114001","firstName": "TEST","lastName": "TEST","gender": "Male","dateOfBirth": "21-11-2014","legalTutors": [],"classroom": {"id": "P1A","year": 1,"section": "A","cycle": 1,"campus": "PRIMARY","students": [{"permanentCode": "FEST120211001","firstName": "TEST","lastName": "FEST","gender": "Female","dateOfBirth": "12-02-2011","legalTutors": [],"classroom": "P1A"},"FEST120412001"]}}]
Can anyone tell what I am doing wrong or how to get my records as I expect them to be?
UPDATE:
When adding @JsonIgnoreProperties({ "students"}) on classroom Attribute in the student class as follow:
@JsonIgnoreProperties({ "students"})private Classroom classroom;
I get the second record details but the classroom inside it is showing the classroom id only, as shown below.
[{"permanentCode": "FEST120412001","firstName": "TEST","lastName": "FEST","gender": "Female","dateOfBirth": "12-04-2012","legalTutors": [],"classroom": {"id": "P1A","year": 1,"section": "A","cycle": 1,"campus": "PRIMARY"}},{"permanentCode": "TEST120211001","firstName": "TEST","lastName": "TEST","gender": "Male","dateOfBirth": "12-02-2011","legalTutors": [],"classroom": "P1A" // No classroom details shown}]
Is there something else missing?
答案1
得分: 0
问题通过在课堂类的顶部按JB Nizet在这个问题中的解释，移除@JsonIdentityInfo( generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")，并且按照Rono在他的评论中建议的方法添加@JsonIgnoreProperties({ "students"})来解决（在此问题的更新中添加）。
英文:
The problem was solved by adding @JsonIgnoreProperties({ "students"}) as suggested by Rono in his comment (added in the update of this question) and by removing @JsonIdentityInfo( generator = ObjectIdGenerators.PropertyGenerator.class, property = "id") from the top of the Classroom class as explained by JB Nizet in this Question.
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