jpa java.lang.StackOverflowError:在Jackson上为空值

dfty9e19  于 2022-11-14  发布在  Java
关注(0)|答案(1)|浏览(148)

我试图创建一个应用程序，允许跟踪快递员，使用Sptring Boot 。但在这里我遇到了一些问题。当我试图调用get_couriers函数，它抛出我这个异常：

java.lang.StackOverflowError: null
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:774) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.13.3.jar:2.13.3]
    at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.13.3.jar:2.13.3]
    at 
    at

我尝试将@JsonIgnore添加到实体的字段中，但没有任何结果;
这是我的实体代码

用户实体

@Table(name = "users")
@Entity
public class UserEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    private String username;
    private String name;
    private String surname;
    private String email;
    private String password;

    @ManyToMany(fetch = FetchType.EAGER)
    @JsonIgnore
    private List<RoleEntity> roles;

    @ManyToOne
    @JoinColumn(name = "user_type_id")
    @JsonIgnore
    private UserTypeEntity userType;

    @ManyToMany(cascade = CascadeType.ALL)
    @JoinTable(
            name = "user_regions",
            joinColumns = @JoinColumn(name = "users_id"),
            inverseJoinColumns = @JoinColumn(name = "regions_id")
    )
    @JsonIgnore
    private List<RegionEntity> regions;

    public UserEntity() {
    }

    public void addRegion(RegionEntity region) {
        regions.add(region);
    }

    public void addRoleToUserRoles(RoleEntity role) {
        roles.add(role);
    }

    public long getId() {
        return id;
    }

    public String getUsername() {
        return username;
    }


    public void setUsername(String username) {
        this.username = username;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
    public UserTypeEntity getUserType() {
        return userType;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    public List<RoleEntity> getRoles() {
        return roles;
    }

    public void setRoles(List<RoleEntity> roles) {
        this.roles = roles;
    }

    public void setUserType(UserTypeEntity userType) {
        this.userType = userType;
    }

    public List<RegionEntity> getRegions() {
        return regions;
    }

    public void setRegions(List<RegionEntity> regions) {
        this.regions = regions;
    }
}

用户类型实体

@Table(name = "user_type")
@Entity

public class UserTypeEntity {
    @Id
    @GeneratedValue
    private long id;
    private String type;
    private double capacity;

    @OneToMany(mappedBy = "userType", cascade = CascadeType.ALL)
    @JsonIgnore
    private List<UserEntity> users = new ArrayList<>();

    public UserTypeEntity() {
    }

    public double getCapacity() {
        return capacity;
    }

    public void setCapacity(double capacity) {
        this.capacity = capacity;
    }

    public long getId() {
        return id;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public List<UserEntity> getUsers() {
        return users;
    }

    public void setUsers(List<UserEntity> users) {
        this.users = users;
    }
}

区域实体

@Table(name = "regions")
@Entity
public class RegionEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;
    private String name;
    @ManyToMany(mappedBy = "regions")
    @JsonIgnore
    private List<UserEntity> couriers;

    public RegionEntity() {
    }

    public long getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<UserEntity> getCouriers() {
        return couriers;
    }

    public void setCouriers(List<UserEntity> couriers) {
        this.couriers = couriers;
    }
}

角色实体

@Table(name = "roles")
@Entity
public class RoleEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    private String name;

    public RoleEntity() {
    }

    public long getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

下面是返回所有快递员的代码，它存储在CourierService.java中，调用CourierController.java：

public List<CourierGetModel> getCouriers() {
        RoleEntity courier = roleService.getRoleByName(Roles.COURIER);
        List<UserEntity> users = userRepo.findAll().stream()
                .filter(x -> x.getRoles().contains(courier)).toList();
        return generateCourierGetModelList(users);
    }

    private List<CourierGetModel> generateCourierGetModelList(List<UserEntity> couriers) {
        List<CourierGetModel> courierModels = new ArrayList<>();
        for(var courier: couriers) {
            courierModels.add(CourierGetModel.toModel(courier));
        }
        return courierModels;
    }

这里是CourierController.java

@RestController
@RequestMapping("/api/courier")
public class CourierController {
    @Autowired
    private CourierService courierService;

    @PostMapping
    public ResponseEntity<Object> addCourier(@RequestBody DefineCourierModel courierData) {
        courierService.addCourier(courierData);
        return ResponseEntity.ok("user was defined as a courier");
    }
    @GetMapping
    public ResponseEntity<Object> getCouriers() {
        return ResponseEntity.ok(courierService.getCouriers());
    }
}

另外，如果需要，这里还有CourierGetModel

public class CourierGetModel {
    private long id;
    private String username;
    private String name;
    private String surname;
    private String email;
    private UserTypeEntity type;
    private List<RegionEntity> regions;

    public CourierGetModel() {
    }

    public static CourierGetModel toModel(UserEntity user) {
        CourierGetModel model = new CourierGetModel();
        model.setUsername(user.getUsername());
        model.setId(user.getId());
        model.setType(user.getUserType());
        model.setRegion(user.getRegions());
        return model;
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public UserTypeEntity getType() {
        return type;
    }

    public void setType(UserTypeEntity type) {
        this.type = type;
    }

    public List<RegionEntity> getRegion() {
        return regions;
    }

    public void setRegion(List<RegionEntity> region) {
        this.regions = region;
    }
}

我对Sptring还是个新手，所以我真的希望你能帮助我。提前谢谢你！

jpa

1条答案

按热度按时间
vybvopom

vybvopom1#

序列化框架（不仅仅是Jackson）不能很好地处理双向多对多关系。当它试图序列化一个UserEntity时，它也试图序列化它的UserTypeEntity。然后，它试图序列化每个UserTypeEntity的所有UserEntity示例，这又导致了UserTypeEntity被序列化。这种情况一直重复，直到发生StackOverflowError。
我认为Jackson在某个地方有一个最大深度设置，这可能会对您有所帮助。其他人也使用过Jackson的注解，比如@JsonIgnore。我自己更喜欢从我的实体创建DTO，这样我就可以对要序列化的内容进行更细粒度的控制。这也允许我为一个具有嵌套UserTypeEntity示例的端点返回UserEntity示例（但不是depper），以及来自另一个的UserTypeEntity示例，其中嵌套了UserEntity示例（但不是更深）。
请注意，@JsonIgnore不起作用，因为Jackson在默认情况下更喜欢使用getter和setter。当您将注解移到getter中，或者让Jackson序列化字段时，错误可能会消失。

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