我真的在努力把一个JSON文件读入Swift,这样我就可以玩它了。我花了2天的时间重新搜索和尝试不同的方法,但没有运气,所以我已经注册了StackOverFlow,看看是否有人能给我指点正确的方向.....

我的JSON文件叫做test。Json,并包含以下内容:

{
  "person":[
     {
       "name": "Bob",
       "age": "16",
       "employed": "No"
     },
     {
       "name": "Vinny",
       "age": "56",
       "employed": "Yes"
     }
  ]
}    

该文件直接存储在文档中,我使用以下代码访问它:

let file = "test.json"
let dirs : String[] = NSSearchPathForDirectoriesInDomains(
                                                          NSSearchpathDirectory.DocumentDirectory,
                                                          NSSearchPathDomainMask.AllDomainMask,
                                                          true) as String[]

if (dirs != nil) {
    let directories: String[] = dirs
    let dir = directories[0]
    let path = dir.stringByAppendingPathComponent(file)
}

var jsonData = NSData(contentsOfFile:path, options: nil, error: nil)
println("jsonData \(jsonData)" // This prints what looks to be JSON encoded data.

var jsonDict = NSJSONSerialization.JSONObjectWithData(jsonData, options: nil, error: nil) as? NSDictionary

println("jsonDict \(jsonDict)") - This prints nil..... 

如果有人能给我一个正确的方向,我可以反序列化JSON文件,并把它放在一个可访问的Swift对象,我会永远感激!

亲切的问候,

Krivvenz。


当前回答

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
      }
}

其他回答

我提供了另一个答案,因为这里没有一个答案是针对从测试包加载资源的。如果您正在使用一个输出JSON的远程服务,并且希望在不触及实际服务的情况下对解析结果进行单元测试,则可以获取一个或多个响应,并将它们放入项目中的Tests文件夹中的文件中。

func testCanReadTestJSONFile() {
    let path = NSBundle(forClass: ForecastIOAdapterTests.self).pathForResource("ForecastIOSample", ofType: "json")
    if let jsonData = NSData(contentsOfFile:path!) {
        let json = JSON(data: jsonData)
        if let currentTemperature = json["currently"]["temperature"].double {
            println("json: \(json)")
            XCTAssertGreaterThan(currentTemperature, 0)
        }
    }
}

这也使用了SwiftyJSON,但获得测试包和加载文件的核心逻辑是问题的答案。

Swift 4:试试我的解决方案:

test.json

{
    "person":[
        {
            "name": "Bob",
            "age": "16",
            "employed": "No"
        },
        {
            "name": "Vinny",
            "age": "56",
            "employed": "Yes"
        }
    ]
}

RequestCodable.swift

import Foundation

struct RequestCodable:Codable {
    let person:[PersonCodable]
}

PersonCodable.swift

import Foundation

struct PersonCodable:Codable {
    let name:String
    let age:String
    let employed:String
}

可解码+ FromJSON.swift

import Foundation

extension Decodable {

    static func fromJSON<T:Decodable>(_ fileName: String, fileExtension: String="json", bundle: Bundle = .main) throws -> T {
        guard let url = bundle.url(forResource: fileName, withExtension: fileExtension) else {
            throw NSError(domain: NSURLErrorDomain, code: NSURLErrorResourceUnavailable)
        }

        let data = try Data(contentsOf: url)

        return try JSONDecoder().decode(T.self, from: data)
    }
}

例子:

let result = RequestCodable.fromJSON("test") as RequestCodable?

result?.person.compactMap({ print($0) }) 

/*
PersonCodable(name: "Bob", age: "16", employed: "No")
PersonCodable(name: "Vinny", age: "56", employed: "Yes")
*/

最新的swift 3.0绝对有效

func loadJson(filename fileName: String) -> [String: AnyObject]?
{
    if let url = Bundle.main.url(forResource: fileName, withExtension: "json") 
{
      if let data = NSData(contentsOf: url) {
          do {
                    let object = try JSONSerialization.jsonObject(with: data as Data, options: .allowFragments)
                    if let dictionary = object as? [String: AnyObject] {
                        return dictionary
                    }
                } catch {
                    print("Error!! Unable to parse  \(fileName).json")
                }
            }
            print("Error!! Unable to load  \(fileName).json")
        }
        return nil
    }

Swift 3.0的更新名称

根据阿比谢克和德鲁瓦的回答

func loadJson(forFilename fileName: String) -> NSDictionary? {

    if let url = Bundle.main.url(forResource: fileName, withExtension: "json") {
        if let data = NSData(contentsOf: url) {
            do {
                let dictionary = try JSONSerialization.jsonObject(with: data as Data, options: .allowFragments) as? NSDictionary

                return dictionary
            } catch {
                print("Error!! Unable to parse  \(fileName).json")
            }
        }
        print("Error!! Unable to load  \(fileName).json")
    }

    return nil
}
//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)")
    }
}