小编Pri*_*ali的帖子

我正在使用Room for my android app.我现在正在尝试设置我的数据库,但是有一条错误消息,表示Dao类必须用@Dao注释.但正如你在编码片段中看到的那样,Dao类用@Dao注释.有谁知道问题或我的错误可能在哪里？两个文件都不在同一个文件夹中(DAO在服务文件夹中,而另一个类在模型文件夹中)

Device.java

@Entity(tableName = "device")
public class Device {

    @PrimaryKey(autoGenerate = true)
    public int device_id;

    @ColumnInfo(name = "identifier")
    public String identifier;

    @ColumnInfo(name = "language")
    public int language;

    @ColumnInfo(name = "searchFilter")
    public int searchFilter;

    public Device(String identifier, int language, int searchFilter){
        this.identifier = identifier;
        this.language = language;
        this.searchFilter = searchFilter;
    }
}

DeviceDAO.java

@Dao
public interface DeviceDAO {
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    void addDevicePreferences(DifficultType difficultType);

    @Query("SELECT * FROM device")
    List<Device> selectAllDevicePreferences();

    @Update(onConflict = OnConflictStrategy.REPLACE)
    void updateDevicePreferences(Device device);
}