这对我很有效

func readjson(fileName: String) -> NSData{

    let path = NSBundle.mainBundle().pathForResource(fileName, ofType: "json")
    let jsonData = NSData(contentsOfMappedFile: path!)

    return jsonData!
}

这在XCode 8.3.3中是可行的

func fetchPersons(){

    if let pathURL = Bundle.main.url(forResource: "Person", withExtension: "json"){

        do {

            let jsonData = try Data(contentsOf: pathURL, options: .mappedIfSafe)

            let jsonResult = try JSONSerialization.jsonObject(with: jsonData, options: .mutableContainers) as! [String: Any]
            if let persons = jsonResult["person"] as? [Any]{

                print(persons)
            }

        }catch(let error){
            print (error.localizedDescription)
        }
    }
}

对于那些希望在decodedable抛出错误后在调试器/ lldb中打印JSON数据的人，请尝试以下方法。

阿宝试试!JSONSerialization。jsonObject(:数据!，选项:.mutableLeaves) as?字典<字符串,任何>

遵循以下代码:

if let path = NSBundle.mainBundle().pathForResource("test", ofType: "json")
{
    if let jsonData = NSData(contentsOfFile: path, options: .DataReadingMappedIfSafe, error: nil)
    {
        if let jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.MutableContainers, error: nil) as? NSDictionary
        {
            if let persons : NSArray = jsonResult["person"] as? NSArray
            {
                // Do stuff
            }
        }
     }
}

数组“persons”将包含关键人物的所有数据。遍历获取它。

斯威夫特4.0:

if let path = Bundle.main.path(forResource: "test", ofType: "json") {
    do {
          let data = try Data(contentsOf: URL(fileURLWithPath: path), options: .mappedIfSafe)
          let jsonResult = try JSONSerialization.jsonObject(with: data, options: .mutableLeaves)
          if let jsonResult = jsonResult as? Dictionary<String, AnyObject>, let person = jsonResult["person"] as? [Any] {
                    // do stuff
          }
      } catch {
           // handle error
      }
}

我可能还会推荐Ray Wenderlich的Swift JSON教程(它还涵盖了很棒的SwiftyJSON替代品，Gloss)。一段摘录(它本身并不能完全回答海报上的问题，但这个答案的附加价值是链接，所以请不要给它加-1):

在Objective-C中，解析和反序列化JSON相当简单:

NSArray *json = [NSJSONSerialization JSONObjectWithData:JSONData
options:kNilOptions error:nil];
NSString *age = json[0][@"person"][@"age"];
NSLog(@"Dani's age is %@", age);

在Swift中，由于Swift的可选选项和类型安全，解析和反序列化JSON有点繁琐，但作为Swift 2.0的一部分，guard语句被引入，以帮助摆脱嵌套的if语句:

var json: Array!
do {
  json = try NSJSONSerialization.JSONObjectWithData(JSONData, options: NSJSONReadingOptions()) as? Array
} catch {
  print(error)
}

guard let item = json[0] as? [String: AnyObject],
  let person = item["person"] as? [String: AnyObject],
  let age = person["age"] as? Int else {
    return;
}
print("Dani's age is \(age)")

当然，在XCode 8中。x，你只需双击空格键，然后说“嘿，Siri，请在Swift 3.0中用空格/制表符缩进为我反序列化这个JSON。”

如果有人正在寻找SwiftyJSON答案: 更新: 对于Swift 3/4:

if let path = Bundle.main.path(forResource: "assets/test", ofType: "json") {
    do {
        let data = try Data(contentsOf: URL(fileURLWithPath: path), options: .alwaysMapped)
        let jsonObj = try JSON(data: data)
        print("jsonData:\(jsonObj)")
    } catch let error {
        print("parse error: \(error.localizedDescription)")
    }
} else {
    print("Invalid filename/path.")
}