android 存储一个list,如何在Android上的RoomDB中保存嵌套的List <String>

嘿谷歌有一个使用@Relation的例子

@Entity

public class Pet {

int userId;

String name;

// other fields

}

public class UserNameAndAllPets {

public int id;

public String name;

@Relation(parentColumn = "id", entityColumn = "userId")

public List pets;

}

是否可以保存String列表而不为其创建额外的类 . 我想避免我的JsonProperty和房间实体之间的混淆

W想拥有那样的东西

public class UserNameAndAllPets {

@JsonProperty("id")

public int id;

@JsonProperty("name")

public String name;

@Relation(parentColumn = "id")

@JsonProperty("pets")

public List pets;

}

因为我收到以下Json：

{

"id" : "1",

"name" : "someName",

"pets": ["cat", "dog", "camel"]

}

谁知道解决方案？

EDIT:

现在我的示例代码看起来像但我有错误：错误：参数的类型必须是使用@Entity或其集合/数组注释的类 .

@JsonIgnoreProperties(ignoreUnknown=true)

@Entity(tableName = TABLE_NAME)

public class Item {

@Ignore public static final String TABLE_NAME = "itemTable";

@PrimaryKey(autoGenerate = true)

Long id;

@JsonProperty("supplierName")

String supplierName;

@JsonProperty("eventDescription")

String eventDescription;

@JsonProperty("eventDate")

@TypeConverters(StringListToGsonConverter.class)

Date date;

@JsonProperty("carServiceType")

@TypeConverters(StringListToGsonConverter.class)

List types;

public ServiceHistoryItem(Long id, String supplierName, String eventDescription, Date date, List types) {

this.id = id;

this.supplierName = supplierName;

this.eventDescription = eventDescription;

this.date = date;

this.types = types;

}

public static class StringListToGsonConverter{

@TypeConverter

public static List restoreList(String listOfString){

return new Gson().fromJson(listOfString, new TypeToken>() {}.getType());

}

@TypeConverter

public static String saveListOfString(List listOfString){

return new Gson().toJson(listOfString);

}

@TypeConverter

public static Date fromTimestamp(Long value) {

return value == null ? null : new Date(value);

}

@TypeConverter

public static Long dateToTimestamp(Date date) {

return date == null ? null : date.getTime();

}

}

}

EDIT2

保存项目时出现新问题Dao无法插入我的实体列表，没有理由为什么......虽然错误：参数的类型必须是使用@Entity或其集合/数组注释的类 .

@Dao

interface ItemDao {

@Query("SELECT * FROM " + Item.TABLE_NAME)

fun getAll(): LiveData>

@Query("DELETE FROM " + Item.TABLE_NAME)

fun deleteAllServiceHistory()

@Insert(onConflict = OnConflictStrategy.REPLACE)

fun insertNewItem(item: Item)

@Insert(onConflict = OnConflictStrategy.REPLACE)

fun insertNewItems(itemList: List) //

}

SOLUTION 为道

如果你使用的是Kotlin，你应该使用ArrayList

@Insert(onConflict = OnConflictStrategy.REPLACE)

fun insertNewItems(itemList: ArrayList)