android - 如何使用带有 Kotlin 的 Room 和 moshi 在其中保存带有 JSON 数组的 JSON 对象

Question

所以，我有这个 JSON 对象

{ 
"name": "News",
"infos":[
   { "title":"hello",
     "content":"this is the content",
     "recent":true
   },
   { "title":"Tax",
     "content":"The European Commission is considering possible tax benefits",
     "recent":true
   },
   { "title":"Tax",
     "content":"The European Commission is considering possible tax benefits",
   }
]

我需要使用 moshi 将此对象与 Room(Android) 持久化，以将此对象反序列化到我的数据类中

@JsonClass(generateAdapter = true)
@Entity(
    tableName = "news"
)

data class News(
    @ColumnInfo(name = "name")
    val name:String = "News",

    val infos:List<Info>,

    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "id")
    val id: Int){
}

@JsonClass(generateAdapter = true)
@Entity(tableName = "info",
    foreignKeys = [
        ForeignKey(entity = News::class, parentColumns = ["id"], childColumns = ["info_id"])
    ],
    indices = [Index("info_id")])
data class Info(
    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "id")
    var id: Int,
    val title : String,
    val content: String,
    val recent: Boolean?,
    @ColumnInfo(name = "info_id")
    val infoId: Int) {

}

我还创建了 Roomd 数据库和我的 @dao 类 @Insert fun。但是我得到这个错误:

error: Cannot figure out how to save this field into database. You can consider adding a type converter for it.
    private final java.util.List<com.example.data.Info> infos = null;

Answer 1

您缺少 TypeConverter。 Room 无法保存复杂的字段类型，如列表、日期、数组等。

请引用: https://developer.android.com/training/data-storage/room/referencing-data