hibernate - 无法将类型“java.lang.String”的属性值转换为属性“user”所需的类型“server.model.User”

问题描述

我这里有点麻烦。试图为我的用户创建 10 个农场。以下是 Famplot 数据类和用户数据类：

@Entity
@IdClass(FarmPlotPK::class)
data class FarmPlot (

    @Id
    val slotnr: Int? = -1,

    @Id
    @ManyToOne
    @JoinColumn(name = "username", nullable = false)
    var user: User,

    val plantedDate: LocalDate? = null,

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "name")
    var plant: Plant? = null
){}

@Entity
@Table(name="user")
data class User (
    @Id
    val username: String = "",


    @OneToMany(mappedBy = "user")
    val farmPlots: MutableSet<FarmPlot> = HashSet()
)

使用我的控制器，我尝试在 FarmPlotController 中使用此方法创建 10 个农场：

    @PostMapping("/farmPlots/create/{username}")
    fun createNewFarmPlot(@PathVariable(value = "username") username:String) {
        val user:User = userRepository.findById(username).get()
        for (i in 0..9) {
            val farmPlot = FarmPlot(slotnr = i, user = user)
            println(farmPlot.toString())
            // Outprint is FarmPlot(slotnr=0, user=User(username=test2, farmPlots=[]), plantedDate=null, plant=null)
            farmPlotRepository.save(farmPlot)
        }
    }

但是，当尝试向用户添加农场图时，我收到以下错误消息：

"message": "Failed to convert property value of type 'java.lang.String' to required type 'com.merchantsofrome.server.model.User' for property 'user'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'com.merchantsofrome.server.model.User' for property 'user': no matching editors or conversion strategy found"

FarmPlotRepository.kt

import com.merchantsofrome.server.model.FarmPlot
import com.merchantsofrome.server.model.IdClass.FarmPlotPK
import org.springframework.data.jpa.repository.JpaRepository
import org.springframework.stereotype.Repository

@Repository
interface FarmPlotRepository : JpaRepository<FarmPlot, FarmPlotPK>

FarmPlotPK.kt

@IdClass(FarmPlotPK::class)
class FarmPlotPK : Serializable {
    var slotnr: Int? = -1
    var user: User? = null

    init{
        this.slotnr=slotnr
        this.user=user
    }

    // The override of equals, see the rules mentioned above for creating a composite primary key
    override fun equals(other: Any?): Boolean {
        if (other is FarmPlotPK) {
            val farmPlotPK = other as FarmPlotPK?
            if (this.user!!.username == farmPlotPK!!.user!!.username && this.slotnr == farmPlotPK.slotnr) {
                return true
            }
        } else {
            return false
        }
        return false
    }

    // The override of hashCode, see the rules mentioned above for creating a composite primary key
    override fun hashCode(): Int {
        return super.hashCode()
    }

}

标签： hibernatespring-bootmodel-view-controllerkotlinspring-data-jpa

hibernate - 无法将类型“java.lang.String”的属性值转换为属性“user”所需的类型“server.model.User”

问题描述

解决方案

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