Java Spring jpa ManyToOne findAll不返回具有相同@ManyToOne属性的第二条记录

我正在使用spring jpa，我有以下课程：

@Entity
@Table(name = "student")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
@JsonIdentityInfo( generator = ObjectIdGenerators.PropertyGenerator.class, property = "permanentCode")
public class Student implements Serializable {

    @Id
    private String permanentCode;
    
    ....

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name="classroom_id")
    private Classroom classroom;

另一类是：

@Entity
@Table(name = "classroom")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
@JsonIdentityInfo( generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
public class Classroom implements Serializable {

    @Id
    private String id;

    ...

    @OneToMany(mappedBy = "classroom", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    private Set<Student> students;

我想要的是：

 [
{
    "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"
        ]
    }
}
]

有人能告诉我做错了什么，或者如何得到我期望的记录吗

更新：

在学生类的教室属性上添加

@JsonIgnoreProperties（{“students”}）

时，如下所示：

@JsonIgnoreProperties({ "students"})
private Classroom classroom;

我得到了第二条记录的详细信息，但里面的教室只显示教室id，如下所示

[
{
    "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
}
]

---

还有什么遗漏吗？

这个问题是通过添加

@JsonIgnoreProperties（{“students”}）

解决的，正如

Rono

在他的评论（在这个问题的更新中添加）中所建议的那样，并删除

@JsonIdentityInfo（generator=ObjectIdGenerators.PropertyGenerator.class，property=“id”）

如

JB Nizet

在本节中所述，从教室的顶端开始。

通过添加

@JsonIgnoreProperties（{“学生”}）

解决了这个问题，正如

Rono

在其评论中所建议的那样（在本问题的更新中添加），并删除

@JsonIdentityInfo（generator=ObjectIdGenerators.PropertyGenerator.class，property=“id”）

位于教室顶部，如本节中的

JB Nizet

所述。

使用

@JsonIgnoreProperties（{“student”}）

在学生课堂内的教室使用

@JsonIgnoreProperties（{“students”}）

在学生课堂内的教室

@JsonIgnoreProperties({ "students"})
private Classroom classroom;

[
{
    "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
}
]