Gson 没有序列化预定义的字段

Question

__type 字段未在 JSON 请求中序列化。虽然 java 版本一切正常。即使我将它放在具有默认值的构造函数或 init 块中也是一样的。我需要这个字段始终是字符串“文件”，但它显然是空的。

@Parcelize
data class File(var url: String?,
                var name: String?) : Parcelable {
    private var __type = "File"
}

与以下代码相同

@Parcelize
data class File(
        @SerializedName("url") var url: String?,
        @SerializedName("name") var name: String?,
        @SerializedName("__type") var type: String = "File") : Parcelable

JSON

{  
    "name":"sample_name.jpg",
    "url":"https://images.com/1123.jpg"
}

Answer 1

试试这个，

class File{
    @SerializedName("name")
    public var name: String? = null
    @SerializedName("url")
    public var url: String? = null
}

Answer 2

您可以在文档中找到使用@Parcelize注解时，只会序列化主构造函数参数：

Instructs the Kotlin compiler to generate `writeToParcel()`, `describeContents()`
[android.os.Parcelable] methods, as well as a `CREATOR` factory class automatically.

The annotation is applicable only to classes that implements
[android.os.Parcelable] (directly or indirectly).
Note that only the primary constructor properties will be serialized.