import com.j256.ormlite.field.types.TimeStampType; //导入依赖的package包/类
@Override
public DataPersister getDataPersister(DataPersister defaultPersister, FieldType fieldType) {
	if (defaultPersister == null) {
		return super.getDataPersister(defaultPersister, fieldType);
	}
	// we are only overriding certain types
	switch (defaultPersister.getSqlType()) {
		case DATE:
			/*
			 * We need to map the dates into their string equivalents because of mapping issues with Sqlite's
			 * default date string formats.
			 */
			if (defaultPersister instanceof TimeStampType) {
				return TimeStampStringType.getSingleton();
			} else if (defaultPersister instanceof SqlDateType) {
				return SqlDateStringType.getSingleton();
			} else {
				return DateStringType.getSingleton();
			}
		default:
			return super.getDataPersister(defaultPersister, fieldType);
	}
}