Swift 2.1答案(基于Abhishek):

    if let path = NSBundle.mainBundle().pathForResource("test", ofType: "json") {
        do {
            let jsonData = try NSData(contentsOfFile: path, options: NSDataReadingOptions.DataReadingMappedIfSafe)
            do {
                let jsonResult: NSDictionary = try NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary
                if let people : [NSDictionary] = jsonResult["person"] as? [NSDictionary] {
                    for person: NSDictionary in people {
                        for (name,value) in person {
                            print("\(name) , \(value)")
                        }
                    }
                }
            } catch {}
        } catch {}
    }

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。”

//change type based on your struct and right JSON file

let quoteData: [DataType] =
    load("file.json")

func load<T: Decodable>(_ filename: String, as type: T.Type = T.self) -> T {
    let data: Data

    guard let file = Bundle.main.url(forResource: filename, withExtension: nil)
        else {
            fatalError("Couldn't find \(filename) in main bundle.")
    }

    do {
        data = try Data(contentsOf: file)
    } catch {
        fatalError("Couldn't load \(filename) from main bundle:\n\(error)")
    }

    do {
        let decoder = JSONDecoder()
        return try decoder.decode(T.self, from: data)
    } catch {
        fatalError("Couldn't parse \(filename) as \(T.self):\n\(error)")
    }
}

一般的方法可以是这样的:

创建响应类名称字符串的json文件

struct Response: Codable,FileDecodable {
    typealias T = Self
    let names:[Data]
}
protocol FileDecodable{
   associatedtype T:Codable
   static func loadJson() ->T?
}

extension FileDecodable{
    static func loadJson() -> T? {
        let fileName = String(describing: T.self)
        if let url = Bundle.main.url(forResource: fileName, withExtension: "json")     {
            do {
                let data = try Data(contentsOf: url)
                let decoder = JSONDecoder()
                let jsonData = try decoder.decode(T.self, from: data)
                return jsonData
            } catch {
                print("error:\(error)")
            }
        }
        return nil
    }
}

Swift 5的答案为我工作，除了我必须添加一个空文件，重命名为xxx。Json，并使用泛型。

func loadJson<T:Codable>(filename fileName: String) -> T? {
        if let url = Bundle.main.url(forResource: fileName, withExtension: "json") {
            do {
                let data = try Data(contentsOf: url)
                let decoder = JSONDecoder()
                return  try decoder.decode(T.self, from: data)
            } catch {
                print("error:\(error)")
            }
        }
        return nil
    }

code

Swift 2.1答案(基于Abhishek):

    if let path = NSBundle.mainBundle().pathForResource("test", ofType: "json") {
        do {
            let jsonData = try NSData(contentsOfFile: path, options: NSDataReadingOptions.DataReadingMappedIfSafe)
            do {
                let jsonResult: NSDictionary = try NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary
                if let people : [NSDictionary] = jsonResult["person"] as? [NSDictionary] {
                    for person: NSDictionary in people {
                        for (name,value) in person {
                            print("\(name) , \(value)")
                        }
                    }
                }
            } catch {}
        } catch {}
    }