解析JSON并使用核心数据Swift 2.0最佳实践进行保存

尼古拉

我想使用核心数据从json文件下载，解析和保存数据。通常我的代码可以工作，但是当json的内容不符合预期时，我会遇到问题。也许有人可以提供一些更好的方法建议。这是我的代码：

//MARK: - REST calls
// This makes the GET call to ATI. It simply gets the some test data
and displays it on the screen.

func getATITodayHoursDataEntertain() {

print("getATITodayHoursDataEntertain")

// set up the base64-encoded credentials
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
config.HTTPAdditionalHeaders = ["Authorization" : authString]

let session = NSURLSession(configuration: config)

let url = NSURL(string: "https://apirest.atinternet-solutions.com/data/v2/json/getData?code=1KVVaC&max-results=30&page-num=1")

session.dataTaskWithURL(url!, completionHandler: { ( data: NSData?, response: NSURLResponse?, error: NSError?) -> Void in
    guard let realResponse = response as? NSHTTPURLResponse where
        realResponse.statusCode == 200 else {
            print("Not a 200 response - getATITodayHoursDataEntertain")
            print(response)
            return
    }

    do {
        if let jsonString = NSString(data:data!, encoding: NSUTF8StringEncoding) {

            let _ = jsonString

            let jsonDictionary = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary
            let jsonContext = ((jsonDictionary["DataFeed"] as! NSArray) [0] as! NSDictionary) ["Context"] as! NSDictionary
            let period = (((jsonContext) ["Periods"] as! NSArray) [0] as! NSDictionary) ["Value"] as! String

            let jsonContent = ((

                ["DataFeed"] as! NSArray) [0] as! NSDictionary) ["Rows"] as! NSArray

            let currentDayTime = jsonContent.count

            var hour0 = 0
            var hour1 = 0
            var hour2 = 0
            var hour3 = 0
            var hour4 = 0
            var hour5 = 0
            var hour6 = 0
            var hour7 = 0
            var hour8 = 0
            var hour9 = 0
            var hour10 = 0
            var hour11 = 0
            var hour12 = 0
            var hour13 = 0
            var hour14 = 0
            var hour15 = 0
            var hour16 = 0
            var hour17 = 0
            var hour18 = 0
            var hour19 = 0
            var hour20 = 0
            var hour21 = 0
            var hour22 = 0
            var hour23 = 0

            if (currentDayTime >= 1) {
                hour0 = (jsonContent[0] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 2) {
                hour1 = (jsonContent[1] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 3) {
                hour2 = (jsonContent[2] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 4) {
                hour3 = (jsonContent[3] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 5) {
                hour4 = (jsonContent[4] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 6) {
                hour5 = (jsonContent[5] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 7) {
                hour6 = (jsonContent[6] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 8) {
                hour7 = (jsonContent[7] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 9) {
                hour8 = (jsonContent[8] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 10) {
                hour9 = (jsonContent[9] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 11) {
                hour10 = (jsonContent[10] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 12) {
                hour11 = (jsonContent[11] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 13) {
                hour12 = (jsonContent[12] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 14) {
                hour13 = (jsonContent[13] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 15) {
                hour14 = (jsonContent[14] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 16) {
                hour15 = (jsonContent[15] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 17) {
                hour16 = (jsonContent[16] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 18) {
                hour17 = (jsonContent[17] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 19) {
                hour18 = (jsonContent[18] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 20) {
                hour19 = (jsonContent[19] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 21) {
                hour20 = (jsonContent[20] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 22) {
                hour21 = (jsonContent[21] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 23) {
                hour22 = (jsonContent[22] as! NSDictionary) ["m_page_loads"] as! Int
            }
            if (currentDayTime >= 24) {
                hour23 = (jsonContent[23] as! NSDictionary) ["m_page_loads"] as! Int
            }

            let jsonTotals = ((jsonDictionary["DataFeed"] as! NSArray) [0] as! NSDictionary) ["Totals"] as! NSArray
            let all = jsonTotals[0] ["m_page_loads"] as! Int

            let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
            let managedContext = appDelegate.managedObjectContext

            let entity =  NSEntityDescription.entityForName("TodayHoursDataEntertain", inManagedObjectContext:managedContext)
            let todayHour = NSManagedObject(entity: entity!, insertIntoManagedObjectContext: managedContext)

            todayHour.setValue(period, forKey: "period")
            todayHour.setValue(hour0, forKey: "hour0")
            todayHour.setValue(hour1, forKey: "hour1")
            todayHour.setValue(hour2, forKey: "hour2")
            todayHour.setValue(hour3, forKey: "hour3")
            todayHour.setValue(hour4, forKey: "hour4")
            todayHour.setValue(hour5, forKey: "hour5")
            todayHour.setValue(hour6, forKey: "hour6")
            todayHour.setValue(hour7, forKey: "hour7")
            todayHour.setValue(hour8, forKey: "hour8")
            todayHour.setValue(hour9, forKey: "hour9")
            todayHour.setValue(hour10, forKey: "hour10")
            todayHour.setValue(hour11, forKey: "hour11")
            todayHour.setValue(hour12, forKey: "hour12")
            todayHour.setValue(hour13, forKey: "hour13")
            todayHour.setValue(hour14, forKey: "hour14")
            todayHour.setValue(hour15, forKey: "hour15")
            todayHour.setValue(hour16, forKey: "hour16")
            todayHour.setValue(hour17, forKey: "hour17")
            todayHour.setValue(hour18, forKey: "hour18")
            todayHour.setValue(hour19, forKey: "hour19")
            todayHour.setValue(hour20, forKey: "hour20")
            todayHour.setValue(hour21, forKey: "hour21")
            todayHour.setValue(hour22, forKey: "hour22")
            todayHour.setValue(hour23, forKey: "hour23")
            todayHour.setValue(all, forKey: "all")

            do {
                try managedContext.save()
                TodayHoursData.append(todayHour)

                print("getATITodayHoursDataEntertain data saved")

            } catch let error as NSError  {
                print("getATITodayHoursDataEntertain - Could not save \(error), \(error.userInfo)")
            }

        }
    } catch {
        print("bad things happened - getATITodayHoursDataEntertain")
    }
}).resume()
}

这是json的示例：

{
DataFeed: [
{
Context: {
Spaces: [
{
Sites: [
{
Id: "560038",
Label: "Entertain VoD TopLists",
Currency: "USD",
TimeZone: "(UTC+01:00) W. Europe Standard Time",
Start: "2015-04-27",
L2s: null
}
]
}
],
Periods: [
{
Value: "2016-05-01T00:00:00,2016-05-01T20:46:59"
}
],
Ranges: [
{
Id: "page-num",
Value: "1"
},
{
Id: "max-results",
Value: "30"
},
{
Id: "url-next",
Value: "https://apirest.atinternet-solutions.com/v2/getdata?page-num=2&filter=%7bd_page_chap1%3a%7b%24eq%3a%27Buy%27%7d%7d&sort=%7bd_time_hour_event%7d&columns=%7bd_time_hour_event%2cm_page_loads%7d&include=%7btotal%3aall%2ccontext%7d&period=%7bR%3a%7bD%3a%270%27%7d%7d&space=%7bs%3a560038%7d&max-results=30"
}
],
Profile: {
Language: "EN",
FirstDayWeek: "Mo"
}
},
Columns: [
{
Name: "d_time_hour_event",
Label: "Hour (event)",
Category: "Dimension",
Type: "Integer",
CustomerType: "Hour"
},
{
Name: "m_page_loads",
Label: "Loads",
Category: "Metric",
Type: "Integer",
CustomerType: "Integer",
Summable: true,
Pie: true
}
],
Rows: [
{
d_time_hour_event: 0,
m_page_loads: 534
},
{
d_time_hour_event: 1,
m_page_loads: 315
},
{
d_time_hour_event: 2,
m_page_loads: 148
},
{
d_time_hour_event: 3,
m_page_loads: 91
},
{
d_time_hour_event: 4,
m_page_loads: 74
},
{
d_time_hour_event: 5,
m_page_loads: 74
},
{
d_time_hour_event: 6,
m_page_loads: 87
},
{
d_time_hour_event: 7,
m_page_loads: 156
},
{
d_time_hour_event: 8,
m_page_loads: 218
},
{
d_time_hour_event: 9,
m_page_loads: 344
},
{
d_time_hour_event: 10,
m_page_loads: 438
},
{
d_time_hour_event: 11,
m_page_loads: 435
},
{
d_time_hour_event: 12,
m_page_loads: 541
},
{
d_time_hour_event: 13,
m_page_loads: 739
},
{
d_time_hour_event: 14,
m_page_loads: 758
},
{
d_time_hour_event: 15,
m_page_loads: 883
},
{
d_time_hour_event: 16,
m_page_loads: 888
},
{
d_time_hour_event: 17,
m_page_loads: 821
},
{
d_time_hour_event: 18,
m_page_loads: 950
},
{
d_time_hour_event: 19,
m_page_loads: 1218
},
{
d_time_hour_event: 20,
m_page_loads: 2000
}
],
Totals: [
{
type: "all",
m_page_loads: 11712
}
]
}
]
}

我的问题是，一天中一个或多个小时没有结果的情况很少发生。在这种情况下，我计算json中项目数的基本方法失败了。谁能给我一个更好的方法来避免这个问题的建议？

我目前正在使用Xcode 7.2，并在swift2中编写了代码。

请不要苛刻。如您所料，我并不是真正的开发人员，而且还是新手。

尼古拉

迈克·巴斯

不必像这样编写小时比较：

if (currentDayTime >= 1) {
  hour0 = (jsonContent[0] as! NSDictionary) ["m_page_loads"] as! Int
}

编写它们的一种更安全的方法如下：

if currentDayTime >= 1, let pageLoads = (jsonContent[0] as? NSDictionary)?["m_page_loads"] as? Int {
    hour0 = pageLoads
}

这就是说“如果一天中的时间> = 1，并且我们当天可以加载页面，则将该值设置为pageLoads，然后设置hour0为pageloads”

之所以比较安全，是因为您有两个as!运算符，分别强制转换为NSDictionary和Int。如果jsonContent[n]不存在，或者如果存在但不包含Int m_page_loads，则将引发错误。我的更安全的方法as?用于两种转换，这意味着以下行：

(jsonContent[0] as? NSDictionary)?["m_page_loads"] as? Int

nil如果无法执行转换，将返回。

另外，除了单独写出每个小时之外，另一种解决方案是遍历JSON中的所有小时，并将它们附加到表示页面加载时间的数组中：

var pageLoadsPerHour = [Int]()
for hour in jsonContent {
    if let pageLoads = (hour as? NSDictionary)?["m_page_loads"] as? Int {
        pageLoadsPerHour.append(pageLoads)
    }
}

希望这可以帮助。

本文收集自互联网，转载请注明来源。

如有侵权，请联系 [email protected] 删除。

编辑于 2020-11-2

我来说两句

0 条评论

登录后参与评论

上一篇：无法从NuGet安装Microsoft.ApplicationInsights 2.0.1

解析JSON并使用核心数据Swift 2.0最佳实践进行保存

解析JSON并使用核心数据Swift 2.0最佳实践进行保存

Qt Creator Windows 10 - “使用 jom 而不是 nmake”不起作用

使用next.js时出现服务器错误，错误：找不到react-redux上下文值；请确保组件包装在<Provider>中

SQL Server中的非确定性数据类型

Swift 2.1-对单个单元格使用UITableView

如何避免每次重新编译所有文件？

在同一Pushwoosh应用程序上Pushwoosh多个捆绑ID

Hashchange事件侦听器在将事件处理程序附加到事件之前进行侦听

应用发明者仅从列表中选择一个随机项一次

在 Avalonia 中是否有带有柱子的 TreeView 或类似的东西？

HttpClient中的角度变化检测

在Wagtail管理员中，如何禁用图像和文档的摘要项？

如何了解DFT结果

Camunda-根据分配的组过滤任务列表

错误：找不到存根。请确保已调用spring-cloud-contract：convert

为什么此后台线程中未处理的异常不会终止我的进程？

构建类似于Jarvis的本地语言应用程序

使用分隔符将成对相邻的数组元素相互连接

您如何通过 Nativescript 中的 Fetch 发出发布请求？

通过iwd从Linux系统上的命令行连接到wifi（适用于Linux的无线守护程序）

使用React / Javascript在Wordpress API中通过ID获取选择的多个帖子/页面

使用 text() 獲取特定文本節點的 XPath