Android 如何使类型转换器与自定义类列表一起工作？

我有一个存储自定义对象通知列表的用户实体。 虽然我使用了类型转换器，但查询时仍然会出错

我的用户实体（省略了getter和setter）

AppDatabase类

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

    private static AppDatabase INSTANCE;

    public abstract UserDao userDao();

    public static AppDatabase getAppDatabase(Context context) {
        if (INSTANCE == null) {
            INSTANCE =
                    Room.databaseBuilder(context.getApplicationContext(), AppDatabase.class, "user-database")
                            .allowMainThreadQueries()
                            .build();
        }
        return INSTANCE;
    }


    public static void destroyInstance() {
        INSTANCE = null;
    }
} 

我发现了错误

error: Not sure how to convert a Cursor to this method's return type

及

---

不确定我错在哪里，因为类型转换器看起来不错。

尝试在

@TypeConverters（converters.class）

下面添加

@columnifo

和

@SerializedName

注释到所有字段，如下所示

@TypeConverters(Converters.class)
@ColumnInfo(name = "notifications")
@SerializedName("notifications")
private List<Notifications> notifications;

---

请将

@ColumnInfo（name=“…”）

添加到

列表通知中

---

条目更新了我的答案，你能试试吗

public class Notifications {
    private String app;
    private String type;
    private String time;


    public Notifications(String app, String type, String time) {
        this.app = app;
        this.type = type;
        this.time = time;
    }
} 

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

    private static AppDatabase INSTANCE;

    public abstract UserDao userDao();

    public static AppDatabase getAppDatabase(Context context) {
        if (INSTANCE == null) {
            INSTANCE =
                    Room.databaseBuilder(context.getApplicationContext(), AppDatabase.class, "user-database")
                            .allowMainThreadQueries()
                            .build();
        }
        return INSTANCE;
    }


    public static void destroyInstance() {
        INSTANCE = null;
    }
} 

error: Not sure how to convert a Cursor to this method's return type

The query returns some columns [notifications] which are not use by com.example.ark.example.database.Notifications. You can use @ColumnInfo annotation on the fields to specify the mapping. com.example.ark.example.database.Notifications has some fields [app, type, time] which are not returned by the query. If they are not supposed to be read from the result, you can mark them with @Ignore annotation. You can suppress this warning by annotating the method with @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH). Columns returned by the query: notifications. Fields in com.example.ark.example.database.Notifications: app, type, time.

@TypeConverters(Converters.class)
@ColumnInfo(name = "notifications")
@SerializedName("notifications")
private List<Notifications> notifications;

@SerializedName("app")
private String app;
@SerializedName("type")
private String type;
@SerializedName("time")
private String time;