kotlin中的數字不可序列化

Question

我發現kotlin中的數字不可序列化。

1. 第一個問題

Device.kt：

package test.domain 

import javax.persistence.* 

Entity public class Device { 
    public Id GeneratedValue var id: Long = -1 
    public var name: String = "" 
    ... 
} 

DeviceRestRepository.kt：

package test.domain 

import org.springframework.data.repository.PagingAndSortingRepository 
import org.springframework.data.repository.query.Param 
import org.springframework.data.rest.core.annotation.RepositoryRestResource 

RepositoryRestResource(collectionResourceRel = "device", path = "device") 
public trait DeviceRestRepository : PagingAndSortingRepository<Device, Long?> { 
    public fun findByName(Param("name") name: String): List<Device> 
} 

我得到一個錯誤，當我嘗試編譯這段代碼，因爲kotlin.Long不是序列化：

Error:(14, 72) Kotlin: Type argument is not within its bounds: should be subtype of 'java.io.Serializable?'

問題二

我得到同樣的錯誤，當我嘗試使用java.lang.Long中：

DeviceRestRepository.kt：

package test.domain 

import org.springframework.data.repository.PagingAndSortingRepository 
import org.springframework.data.repository.query.Param 
import org.springframework.data.rest.core.annotation.RepositoryRestResource 

RepositoryRestResource(collectionResourceRel = "device", path = "device") 
public trait DeviceRestRepository : PagingAndSortingRepository<Device, java.lang.Long?> { 
    public fun findByName(Param("name") name: String): List<Device> 
} 

Warning:(14, 72) Kotlin: This class shouldn't be used in Kotlin. Use kotlin.Long instead.

Error:(14, 72) Kotlin: Type argument is not within its bounds: should be subtype of 'java.io.Serializable?'

Answer 1

由於Kotlin 1.0 Beta 1原始類型是s erializable：

Int is Serializable

Now the type Int and other basic types are Serializable on the JVM. This should help many frameworks.

來自： http://blog.jetbrains.com/kotlin/2015/10/kotlin-1-0-beta-candidate-is-out/

因此你不再有任何問題。

Answer 2

我偶然發現了同樣的問題，並設法通過在java中使用我的Repository接口來處理它，在那裏我將java.lang.Long作爲id的泛型類型參數。其餘的則留在科特林（數據類，服務類等）

Answer 3

我發現這個問題的解決方法：

Device.kt：

package test.domain 

import javax.persistence.* 

Entity public class Device { 
    public EmbeddedId var id: DeviceId = DeviceId() 
    public var name: String = "" 
    ... 
} 

Embeddable public class DeviceId: Serializable { 
    public GeneratedValue var id: Long = -1 
} 

DeviceRestRepository.kt：

package test.domain 

import org.springframework.data.repository.PagingAndSortingRepository 
import org.springframework.data.repository.query.Param 
import org.springframework.data.rest.core.annotation.RepositoryRestResource 

RepositoryRestResource(collectionResourceRel = "device", path = "device") 
public trait DeviceRestRepository : PagingAndSortingRepository<Device, DeviceId?> { 
    public fun findByName(Param("name") name: String): List<Device> 
} 

這個用例工作正常