资源预下载和本地通知.md 13.1 KB

Raw Blame History Permalink


返回在线授课相关文档


资源预下载


教师版和学生版都需要提前预下载资源，不同的是教师版课程结束后不用删除缓存，因为有可能会反复教同一课。
课表信息缓存在本地
根据课表返回的信息中寻找从当前起7天后的的课程Id，从盒子鱼服务器获取相应的资源列表
在后台预下载资源
如果用户是在非Wifi状态下，提醒用户是否允许继续下载
在开始上课的时候，如果检测到还有需要下载的资源，则用正常的前台下载，不用开启后台下载。
上完课要及时清除学生端的缓存，需要记住学生下载的资源和相对应的课程信息


资源预下载的检查时机


每次App启动的时候
App从后台进入前台
用户打开课表
学生用户买课之后（系统会立刻匹配上该学生应该上哪些课）


App会从盒子鱼服务器获取最新的课表信息，如果课表有变化（根据Etag值判断），则更新本地缓存。
获取课表信息之后，通知资源预下载检查器进行检查，是否有资源需要预下载。


可能需要的下载类


资源下载检查器


启动的时候，检查是否有缓存的当月的课表。
从当月的课表中取出从当前时间到月底之间的课程Id列表
根据本地的缓存判断是否已经下载了某一课的全部资源
如果未下载某一课的全部资源，则检查本地是否有该课的资源列表
 如果有该课资源列表，则去列表中寻找未下载的资源进行下载
 如果没有该课资源列表，则从盒子鱼服务器获取该列表 


资源下载器


可以根据资源列表后台下载资源
下载过程中某个资源出错的话，可以跳过继续下载其他的资源
在前台下载的时候需要停掉资源下载器的后台资源下载
需要检测网络状态的变化，当用户处于非Wifi状态下，需要暂停下载，询问用户是否继续下载。


资源下载需要考虑的问题
  下载的时候，先把下载的数据保存成一个临时文件，等下载成功的时候再保存为最终的文件名
  下载后的资源需要进行MD5验证，对资源数据进行MD5运算后应该和资源名一致
  下载后的资源除了视频（"Content-Type"为"video"）外其他需要进行加密处理
IOS端可以参考DownloadManager中类似的处理


资源缓存管理器


把在线授课所需的资源列表缓存到数据库中
学生端在授课结束后根据缓存信息删除掉该课的资源，删除资源后同时删除缓存的资源列表信息
在设置中进行清除缓存的操作的时候，需要清除缓存的资源列表信息


在线授课课表信息缓存设计

采用缓存文件


IOS端的缓存目录获取方法

可以从BFECourseInfoCacheManager的
getTimeTableCacheFilePathByYear:(NSString *)year andMonth:(NSString *)month方法中读取
BFECourseInfoCacheManager的创建可以用以下抽象工厂中提供的方法
BFECourseInfoCacheManager *courseInfoCacheManager = [[BoxfishFactory getFactory] createCourseInfoCacheManager];


在线授课本地资源存储设计

IOS端拟采用数据库进行管理，数据库名暂定为OnlineTeachResource.db

可以利用BFECourseInfoCacheManager的
getOnlineTeachCourseResourceInfoFilePath获取;


课程列表: courseList.table(暂定)


课程Id
资源表名
lastModified
状态


课程Id1
list1
最后更新时间
已下载


课程Id2
list2
最后更新时间
未下载


课程Id3
list3
最后更新时间
未下载


如果检查到本地缓存的lastModified和课表提供的该课的lastModified不一致，
则需要重新下载该课的资源列表，下载后更新lastModified为最新值


资源列表: list1.table(暂定)


资源Id
是否下载


资源Id1
true


资源Id2
true


资源Id3
false


本地通知或者闹铃，提前通知用户打开App，准备上课


课表缓存信息（需要追加lastModified信息）


学生端课表缓存内容

{
 "data": [
    {
        "day": "2016-04-12",
        "dailyScheduleTime": [
            {
                "id": 338345,
                "time": "14:00:00",
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            },
            {
                "id": 338346,
                "time": "15:00:00",
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            },
            {
                "id": 338347,
                "time": "16:00:00",
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            }
        ]
    }
]
}


教师端课表缓存信息

{
 "data": [
    {
        "day": "2016-04-12",
        "dailyScheduleTime": [
            {
                "slotId": 1,
                "startTime": "08:00:00",
                "endTime": "09:00:00",
                "selected": true,
                "status": 1,
                "workOrderId": null,
                "courseInfo": null
            },
            {
                "slotId": 9,
                "startTime": "16:00:00",
                "endTime": "17:00:00",
                "selected": true,
                "status": 2,
                "workOrderId": 26,
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            }
        ]
    },
    {
        "day": "2016-04-13",
        "dailyScheduleTime": [
            {
                "slotId": 1,
                "startTime": "08:00:00",
                "endTime": "09:00:00",
                "selected": true,
                "status": 2,
                "workOrderId": 26,
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            },
            {
                "slotId": 2,
                "startTime": "09:00:00",
                "endTime": "10:00:00",
                "selected": true,
                "status": 2,
                "workOrderId": 26,
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            },
            {
                "slotId": 3,
                "startTime": "10:00:00",
                "endTime": "11:00:00",
                "selected": true,
                "status": 2,
                "workOrderId": 26,
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            },
            {
                "slotId": 4,
                "startTime": "11:00:00",
                "endTime": "12:00:00",
                "selected": true,
                "status": 2,
                "workOrderId": 26,
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            },
            {
                "slotId": 5,
                "startTime": "12:00:00",
                "endTime": "13:00:00",
                "selected": true,
                "status": 2,
                "workOrderId": null,
                "courseInfo": {
                    "name": "Unit 3 Topic 3 What would you like to drink?",
                    "thumbnail": "http://192.168.0.100/pub/student/publication/data/data/9563a30efded2cc111927542b2316e81",
                    "courseType": [
                        "课文朗读"
                    ],
                    "difficulty": [
                        "1"
                    ],
                    "lastModified": 1448375675242,
                    "courseId": "L3NoYXJlL3N2bi_ku4HniLHkuIPkuIog5ZCs6K-7LzAzMi5Vbml0IDMgVG9waWMgMyBXaGF0IHdvdWxkIHlvdSBsaWtlIHRvIGRyaW5rPy54bHN4"
                }
            },
            {
                "slotId": 6,
                "startTime": "13:00:00",
                "endTime": "14:00:00",
                "selected": true,
                "status": 1,
                "workOrderId": null,
                "courseInfo": null
            }
        ]
    }
]
}