房间数据库中的自定义对象数组

Question

我正在尝试为我的 Android 应用程序创建一个 Room 数据库，但我运行遇到了自定义对象数组的问题。

错误信息：

java.lang.IllegalArgumentException: cz.polreich.banks.model.airBank.OpeningHoursDay[]cannot be converted to an Element

这是嵌入有问题数组的对象：

@Entity
public class OpeningHours  {

@PrimaryKey(autoGenerate = true)
private int ohId;
private boolean isNonstop;
@Embedded
private OpeningHoursDay[] days;

public OpeningHours() {
}

// getters and setters

这是我的数据库定义：

@Database(version = 1, entities = {OpeningHours.class, OpeningHoursDay.class})
abstract class AppDatabase extends RoomDatabase {
@TypeConverters({Converters.class})

abstract public BranchDao branchDao();
}

我也有我希望的类型转换器，应该通过将数组转换为 List 并返回来解决这个问题，但它没有帮助：

public class Converters {
@TypeConverter
public List<OpeningHoursDay> fromOpeningHoursDayArray(OpeningHoursDay[] ohda){
    List<OpeningHoursDay> ohdList = new ArrayList<>();
    ohdList.addAll(Arrays.asList(ohda));
    return ohdList;
}

@TypeConverter
public OpeningHoursDay[] toOpeningHoursDayArray(List<OpeningHoursDay> ohdList){
    OpeningHoursDay[] ohda = null;
    for (int i = 0; i < ohdList.size(); i++) {
        ohda[i] = ohdList.get(i);
    }
    return ohda;
}
}

编辑： 我试图更改 TypeConverter 以将对象转换为 json，但没有帮助：

public class Converters {

Gson gson = new Gson();

@TypeConverter
public String fromOpeningHoursDayArray(OpeningHoursDay[] ohda){
    ArrayList<OpeningHoursDay> ohdList = new ArrayList<>();
    ohdList.addAll(Arrays.asList(ohda));
    return gson.toJson(ohdList);
}

@TypeConverter
public OpeningHoursDay[] toOpeningHoursDayArray(String ohdJson){
    ArrayList<OpeningHoursDay> ohdList = new ArrayList<>();
    ohdList = gson.fromJson(ohdJson, new TypeToken<ArrayList<OpeningHoursDay>>(){}.getType());
    OpeningHoursDay[] ohda = null;
    for (int i = 0; i < ohdList.size(); i++) {
        ohda[i] = ohdList.get(i);
    }
    return ohda;
}

}

有人知道如何解决这个问题吗？

Answer 1

删除自定义对象数组的 @Embedded 注释解决了这个问题。

房间数据库中的自定义对象数组

Array of custom objects in Room Database

android

database

android-sqlite

android-room

custom-object