objective-c - 如何在 Swift 或 Objective-C 中获取 JSON 数据结构的人类可读映射？

Question

阅读和理解 JSON 字符串表示可能非常乏味。有没有办法以人类可读的方式显示嵌套数组/字典的结构？

Answer 1

我是 stackoverflow 的新手，所以我不知道回答自己的问题是否礼貌。

在过去的几天里，我注意到一些关于识别 JSON 数据结构的问题。

所以我在 Swift 中写了一个小类 JSONStructure 来显示层次结构，只用 prinln() 和 tab 字符作为缩进Xcode 的调试控制台。

例如 Apple 推送通知负载之一——这里是 JSON 表示——...

{
   "aps" : {
      "alert” : {
         “body” : "Acme message received from Johnny Appleseed”,
         “action-loc-key” : “VIEW”,
         "actions" : [
            {
               “id" : “delete",
               "title" : "Delete"
            },
            {
               “id" : “reply-to”,
               "loc-key" : “REPLYTO”,
               "loc-args" : [“Jane"]
            }
         ]
      },
      "badge" : 3,
      "sound" : “chime.aiff"
   },
   "acme-account" : "jane.appleseed@apple.com",
   "acme-message" : "message123456"
}

...会这样显示

    root node is Dictionary with 3 keys 'aps, acme-message, acme-account'
         node 'aps' is Dictionary with 3 keys 'sound, alert, badge'
             node 'alert' is Dictionary with 3 keys 'action-loc-key, actions, body'
                 node 'actions' is Array with 2 items
                     node [0] is Dictionary with 2 keys 'id, title'
                     node [1] is Dictionary with 3 keys 'id, loc-args, loc-key'
                         node 'loc-args' is Array with 1 items

---

JSONStructure 是一个静态类，不需要使用初始化器

基本功能有3个

 JSONStructure.fromFileAtURL("http://domain.com/file.json")

从文件或 URL 中读取 JSON

 JSONStructure.fromString("{\"key\":\"value\"}")

从纯字符串读取 JSON

 JSONStructure.fromData(data : NSData)

是从NSData对象中读取JSON的指定函数

JSONStructure使用了NSURLConnection和NSJSONSerialization的同步方法sendSynchronousRequest。不需要第三方类。

---

class JSONStructure {

  static var indent = ""

  // check JSON from URL or file path,
  // can be http://domain.com/file.json or /Library/Folder/file.json
  class func fromFileAtURL(urlOrPath : String)
  {
    var response: NSURLResponse?
    var error : NSError?
    let isHttpURL = urlOrPath.hasPrefix("http")
    if let url = isHttpURL ?  NSURL(string : urlOrPath) : NSURL(fileURLWithPath : urlOrPath) {
      let data : NSData?
      let request = NSURLRequest(URL: url)
      if let data = NSURLConnection.sendSynchronousRequest(request, returningResponse: &response, error: &error) {
        if let httpResponse = response as? NSHTTPURLResponse {
          println("Response statusCode: \(httpResponse.statusCode)")
        }
        JSONStructure.fromData(data)
      } else if error != nil {
        println("URLConnection error: \(error!)")
      }
    } else {
      println("Bad URL")
    }
  }

  // check JSON from plain string
  class func fromString(string : String)
  {
    if let data = string.dataUsingEncoding(NSUTF8StringEncoding) {
      JSONStructure.fromData(data)
    } else {
      println("could not create NSData object from string")
    }
  }

  // check JSON from NSData object
  class func fromData(data : NSData)
  {
    indent = ""
    var jsonError : NSError?
    let jsonObject: AnyObject? = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions(), error: &jsonError)
    if jsonError != nil {
      println("JSONSerialization error: \(jsonError!)")
    } else {
      if let jsonArray = jsonObject as? Array<AnyObject> {
        println("root node is Array with \(jsonArray.count) items")
        processSubArray(jsonArray)
      } else if let jsonDictionary = jsonObject as? Dictionary<String,AnyObject> {
        let formattedKeys = join(", ", jsonDictionary.keys.array)
        println("root node is Dictionary with \(jsonDictionary.count) keys '\(formattedKeys)'")
        processSubDictionary(jsonDictionary)
      }
    }
  }

  // recursive function to process an Array node in the JSON structure
  private class func processSubArray(jsonArray : Array<AnyObject>)
  {
    indent += "\t"
    for (index, subNode) in enumerate(jsonArray) {
      if let subArray = subNode as? Array<AnyObject> {
        println("\(indent) node [\(index)] is Array with \(subArray.count) items")
        processSubArray(subArray)
      } else if let subDictionary = subNode as? Dictionary<String,AnyObject>{
        let formattedKeys = join(", ", subDictionary.keys.array)
        println("\(indent) node [\(index)] is Dictionary with \(subDictionary.count) keys '\(formattedKeys)'")
        processSubDictionary(subDictionary)
      }
    }
    indent = indent.substringToIndex(indent.endIndex.predecessor())
  }

  // recursive function to process a Dictionary node in the JSON structure
  private class func processSubDictionary(jsonDictionary : Dictionary<String,AnyObject>)
  {
    indent += "\t"
    for (key, value) in jsonDictionary {
      if let subArray = value as? Array<AnyObject> {
        println("\(indent) node '\(key)' is Array with \(subArray.count) items")
        processSubArray(subArray)
      } else if let subDictionary = value as? Dictionary<String,AnyObject>{
        let formattedKeys = join(", ", subDictionary.keys.array)
        println("\(indent) node '\(key)' is Dictionary with \(subDictionary.count) keys '\(formattedKeys)'")
        processSubDictionary(subDictionary)
      }
    }
    indent = indent.substringToIndex(indent.endIndex.predecessor())
  }

}