将 JSON 字符串设为 Kotlin 对象不起作用

Question

我正在尝试向后端发送一个 multipart/formdata 对象，其中包含一个 Freelancer 对象和两个必须存储在服务器上的图像文件。保存在光盘部分有效，但将 JSON 字符串保存为自由职业者对象无效。我尝试使用 Jackson objectmapper 转换字符串，但我认为我做错了什么。当我调试应用程序时，它在 mapper.readValue 崩溃并直接进入 catch().

我也尝试使用 kotlinx.serializer，但导入不起作用，所以我切换到 Jackson。

接受请求的 Kotlin 控制器：

   private val imageDirectory = System.getProperty("user.dir") + "/images/"
@PostMapping(consumes = ["multipart/form-data"])
fun saveUser(
        @RequestParam("profileImage") profileImage: MultipartFile,
        @RequestParam("fileIdImage") fileIdImage: MultipartFile,
        @RequestParam("freelancer") freelancer: String,
): ResponseEntity<*> {
    return try {
        val mapper = ObjectMapper();
        val freelancerJson: Freelancer = mapper.readValue(freelancer, Freelancer::class.java)
        println(freelancerJson.aboutYou)

        makeDirectoryIfNotExist(imageDirectory)
        val profileImagePath: Path = Paths.get(imageDirectory, profileImage.originalFilename)
        val idImagePath: Path = Paths.get(imageDirectory, fileIdImage.originalFilename)
        Files.write(profileImagePath, profileImage.bytes);
        Files.write(idImagePath, fileIdImage.bytes);
        JsonResponse(HttpStatus.OK, "Saved freelancer} ").createResponseEntity()
    } catch (e: Exception) {
        JsonResponse(HttpStatus.INTERNAL_SERVER_ERROR, e.message.toString()).createResponseEntity()
    }
}

前端使用vue的请求：

表单数据的控制台输出：

自由职业者模型：

@Entity
data class Freelancer(
    @Id
    val id: Int,

    //maps ID to freelancer primary key
    @MapsId
    @OneToOne(targetEntity = User::class)
    @JoinColumn(name = "freelancer_id")
    //ignores the freelancer id because it is already mapped to val id
    @JsonIgnore
    val freelancerId: User,

    val firstName: String? = null,

    val lastName: String? = null,

    val dateOfBirth: Date? = null,
    val kvk: String? = null,
    val btw: String? = null,
    val phone: String? = null,
    val street: String? = null,
    val zipcode: String? = null,
    val city: String? = null,
    val housenumber: Int? = 0,
    val addition: String? = null,
    val nameCardHolder: String? = null,
    val iban: String? = null,
    val referral: String? = null,
    val specialism: String? = null,
    val aboutYou: String? = null,
    val motivation: String? = null,
    val workExperience: Int? = null,
    val driverLicense: Boolean? = null,
    val ownTransport: Boolean? = null,
    val identificationImage: String? = null,
    val smallBusinessScheme: Boolean? = false,
    val profileImage: String? = null,
    val previousWorkedPlatform: String? = null,
    val servicesAmount: Int? = null,
    val previousWorkedRating: Int? = null,
    val foundBy: String? = null,
    val privacyStatement: Boolean? = null,

    )

Answer 1

我通过向发送到后端的 Json 对象添加 ID 解决了这个问题，因为我的模型与另一个模型有一对一的关系，所以我在映射 [= 时必须包含它12=] 到模型。

将 JSON 字符串设为 Kotlin 对象不起作用

Making JSON string to Kotlin object not working

spring

json

jackson

kotlin

spring-boot