房间数据库架构实体扩展错误

在使用android Room时,我拥有以下实体:

@Entity
public class Call implements Parcelable {

@PrimaryKey(autoGenerate = true)
private long id;
private String filePath;
private long durationInMillis;
private String phoneNumber;
private int isStarred;
private int isIncoming;
private long timestampCreated;
}

一切都很好。但现在我希望我的pojo(Call.class)扩展一个抽象类,如下所示:

@Entity
public class Call extends BaseViewTypeData implements Parcelable {
....
....
}

Error:Cannot figure out how to save this field into database. You can 
consider adding a type converter for it.
Error:Cannot find getter for field.
Error:Cannot find setter for field.
Error:Cannot figure out how to read this field from a cursor.
Error:Cannot find getter for field.
Error:Cannot find setter for field.

父类(BaseViewTypeData.class)是一个简单的类,用于处理回收器视图中的多种视图类型。

public abstract class BaseViewTypeData extends BaseObservable {

public static final int VIEW_TYPE_CALL = 0;
public static final int VIEW_TYPE_SETTINGS_HEADER = 1;
public static final int VIEW_TYPE_SETTINGS_TITLE_SUBTITLE = 2;
public static final int VIEW_TYPE_SETTINGS_TITLE_SUBTITLE_SWITCH = 3;
public static final int VIEW_TYPE_SETTINGS_DIVIDER = 4;
public static final int VIEW_TYPE_SETTINGS_TITLE_SWITCH = 5;
public static final int VIEW_TYPE_CALL_LOG_DATA = 6;
public static final int VIEW_TYPE_CHECKBOX_TITLE_SUBTITLE = 7;

@Ignore
public abstract int getViewType();

}