Question

我正在使用spring框架，Hibernate和JSON开发rest web app。假设我有两个实体，如下所示：

University.java

 public class University extends BaseEntity {

    private String name;
    private String address;
    private String telephon;


    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER,orphanRemoval = true,mappedBy = "university")
    @JsonManagedReference
    private List<Student> students=new ArrayList<>();
// setter an getter
}

Student.java

public class Student extends BaseEntity{

    private String firstName;

    private String lastName;

    private String section;

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "UNIVERSITY_ID",nullable = false)
    @JsonBackReference
    private University university;

// setter an getter
    }

我的要求：

当我打电话给学生列表api时，我需要在每个学生对象中都有Usiversity对象，我需要什么样的配置或注释来处理这种情况？结果是：

   [
    {
        "id": 1,
        "firstName": "aa",
        "lastName": "aa",
        "section": "aa"
    },
    {
        "id": 2,
        "firstName": "bb",
        "lastName": "bb",
        "section": "bb"
    },
    {
        "id": 3,
        "firstName": "cc",
        "lastName": "cc",
        "section": "cc"
    }
]

我需要有这样的回复当我打电话给学生名单

   [
    {
        "id": 1,
        "firstName": "aa",
        "lastName": "aa",
        "section": "aa",
        "university": {
            "id": 1,
            "name": "string",
            "address": "string",
            "telephon": "string"
        }
    },
    {
        "id": 2,
        "firstName": "bb",
        "lastName": "bb",
        "section": "bb",
        "university": {
            "id": 1,
            "name": "string",
            "address": "string",
            "telephon": "string"
        }
    },
    {
        "id": 3,
        "firstName": "cc",
        "lastName": "cc",
        "section": "cc",
        "university": {
            "id": 3,
            "name": "www",
            "address": "www",
            "telephon": "www"
        }
    }
]

更新

对于大学名单我需要这个回复

[
    {
        "id": 1,
        "name": "string",
        "address": "string",
        "telephon": "string",
        "students": [
            {
                "id": 1,
                "firstName": "aa",
                "lastName": "aa",
                "section": "aa"
            },
            {
                "id": 2,
                "firstName": "bb",
                "lastName": "bb",
                "section": "bb"
            }
        ]
    },
    {
        "id": 3,
        "name": "www",
        "address": "www",
        "telephon": "www",
        "students": [
            {
                "id": 3,
                "firstName": "cc",
                "lastName": "cc",
                "section": "cc"
            }
        ]
    }
]

任何帮助和建议表示赞赏。

Answer 1

我认为杰克逊的注释被宣布为错误的方式：

@JsonManagedReference是引用的前向部分 - 正常序列化的部分。

@JsonBackReference是引用的后半部分 - 它将从序列化中省略。

Spring Rest和Hibernate以及JSON dosnt按预期工作

1 个答案: