工厂方法实现

Question

我在浏览SO中的“工厂方法”页面时，偶然发现了这个link。和this comment。该示例看起来像是一个变体，并以其原始的方式实现:将实例化推迟到子类...

这是我的尝试。下面的代码是否实现了链接中指定的示例的工厂模式？请验证并建议是否需要进行任何重构。

public class ScheduleTypeFactoryImpl implements ScheduleTypeFactory {

    @Override
    public IScheduleItem createLinearScheduleItem() {
            return new LinearScheduleItem();
    }

    @Override
    public IScheduleItem createVODScheduleItem() {
     return new VODScheduleItem();
    }

}

public class UseScheduleTypeFactory {

    public enum ScheduleTypeEnum {
        CableOnDemandScheduleTypeID, 
            BroadbandScheduleTypeID, 
            LinearCableScheduleTypeID, 
            MobileLinearScheduleTypeID
    }

    public static IScheduleItem getScheduleItem(ScheduleTypeEnum scheduleType) {
        IScheduleItem scheduleItem = null;
        ScheduleTypeFactory scheduleTypeFactory = new ScheduleTypeFactoryImpl();
        switch (scheduleType) {
        case CableOnDemandScheduleTypeID:
            scheduleItem = scheduleTypeFactory.createVODScheduleItem();
            break;

        case BroadbandScheduleTypeID:
            scheduleItem = scheduleTypeFactory.createVODScheduleItem();
            break;

        case LinearCableScheduleTypeID:
            scheduleItem = scheduleTypeFactory.createLinearScheduleItem();
            break;

        case MobileLinearScheduleTypeID:
            scheduleItem = scheduleTypeFactory.createLinearScheduleItem();
            break;
        default:
            break;
        }
        return scheduleItem;
    }
}

Answer 1

我会说这是可以的，尽管在我看来过于复杂。您并不真正需要ScheduleTypeFactoryImpl类。然后，您可以仅将UseScheduleTypeFactory类更改为ScheduleTypeFactory。

我是这样想的：

公共类ScheduleTypeFactory {

public enum ScheduleTypeEnum {
    CableOnDemandScheduleTypeID, 
        BroadbandScheduleTypeID, 
        LinearCableScheduleTypeID, 
        MobileLinearScheduleTypeID
}

public static IScheduleItem getScheduleItem(ScheduleTypeEnum scheduleType) {
    IScheduleItem scheduleItem = null;
    switch (scheduleType) {
    case CableOnDemandScheduleTypeID:
        scheduleItem = new VODScheduleItem();
        break;

    case BroadbandScheduleTypeID:
        scheduleItem = new VODScheduleItem();
        break;

    case LinearCableScheduleTypeID:
        scheduleItem = new LinearScheduleItem();
        break;
    case MobileLinearScheduleTypeID:
        scheduleItem = new LinearScheduleItem();
        break;
    default:
        break;
    }
    return scheduleItem;
}

}

你可能想要包括一个“默认”的情况。