Question

我真的很想尝试将一个JSON文件读入Swift，所以我可以玩它。我已经花了2天的时间重新搜索并尝试不同的方法但是没有运气，所以我已经注册StackOverFlow，看看是否有人可以指出我正确的方向.....

我的JSON文件名为test.json，包含以下内容：

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

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.....

如果有人能够正确指导我如何对JSON文件进行反序列化并将其放入可访问的Swift对象中，我将永远感激不尽！

亲切的问候，

Krivvenz。

Answer 1

请按照以下代码：

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“人员”将包含关键人物的所有数据。迭代摘要来获取它。

Swift 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
      }
}

Answer 2

如果有人正在寻找SwiftyJSON答案：
的更新
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.") }

Answer 3

使用可解码的Swift 4

struct ResponseData: Decodable {
    var person: [Person]
}
struct Person : Decodable {
    var name: String
    var age: String
    var employed: String
}

func loadJson(filename fileName: String) -> [Person]? {
    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(ResponseData.self, from: data)
            return jsonData.person
        } catch {
            print("error:\(error)")
        }
    }
    return nil
}

Swift 3

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

Answer 4

Xcode 8 Swift 3 从文件更新中读取json：

    if let path = Bundle.main.path(forResource: "userDatabseFakeData", ofType: "json") {
        do {
            let jsonData = try NSData(contentsOfFile: path, options: NSData.ReadingOptions.mappedIfSafe)
            do {
                let jsonResult: NSDictionary = try JSONSerialization.jsonObject(with: jsonData as Data, options: JSONSerialization.ReadingOptions.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 {}
    }

Answer 5

Swift 5.1，Xcode 11

您可以使用此：


struct Person : Codable {
    let name: String
    let lastName: String
    let age: Int
}

func loadJson(fileName: String) -> Person? {
   let decoder = JSONDecoder()
   guard
        let url = Bundle.main.url(forResource: fileName, withExtension: "json"),
        let data = try? Data(contentsOf: url),
        let person = try? decoder.decode(Person.self, from: data)
   else {
        return nil
   }

   return person
}

Answer 6

更新了Swift 3.0的名称

基于Abhishek's answer和Druva's answer

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
}

Answer 7

Swift 3.0，Xcode 8，iOS 10

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

        do {
            let jsonData = try Data(contentsOf: path, options: .mappedIfSafe)
            do {
                if let jsonResult = try JSONSerialization.jsonObject(with: jsonData, options: JSONSerialization.ReadingOptions(rawValue: 0)) as? NSDictionary {
                    if let personArray = jsonResult.value(forKey: "person") as? NSArray {
                        for (_, element) in personArray.enumerated() {
                            if let element = element as? NSDictionary {
                                let name = element.value(forKey: "name") as! String
                                let age = element.value(forKey: "age") as! String
                                let employed = element.value(forKey: "employed") as! String
                                print("Name: \(name),  age: \(age), employed: \(employed)")
                            }
                        }
                    }
                }
            } catch let error as NSError {
                print("Error: \(error)")
            }
        } catch let error as NSError {
            print("Error: \(error)")
        }
    }

<强> 输出：

Name: Bob,  age: 16, employed: No
Name: Vinny,  age: 56, employed: Yes

Answer 8

Swift 2.1回答（基于Abhishek＆＃39;）

[2015-11-08 17:36:53 -0500] [15848] [ERROR] Error handling request
Traceback (most recent call last):
  File "[...]/venv/lib/python2.7/site-packages/gunicorn/workers/sync.py", line 130, in handle
    self.handle_request(listener, req, client, addr)
  File "[...]/venv/lib/python2.7/site-packages/gunicorn/workers/sync.py", line 176, in handle_request
    for item in respiter:
  File "[...]/app.py", line 33, in __call__
    stream = LimitedStream(environ['wsgi.input'], int(environ['CONTENT_LENGTH'] or 0))
KeyError: 'CONTENT_LENGTH'

Answer 9

fileprivate class BundleTargetingClass {}
func loadJSON<T>(name: String) -> T? {
  guard let filePath = Bundle(for: BundleTargetingClass.self).url(forResource: name, withExtension: "json") else {
    return nil
  }

  guard let jsonData = try? Data(contentsOf: filePath, options: .mappedIfSafe) else {
    return nil
  }

  guard let json = try? JSONSerialization.jsonObject(with: jsonData, options: .allowFragments) else {
    return nil
  }

  return json as? T
}

copy-paste ready，第三方框架独立解决方案。

用法

let json:[[String : AnyObject]] = loadJSON(name: "Stations")!

Answer 10

这对我很有用

func readjson(fileName: String) -> NSData{

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

    return jsonData!
}

Answer 11

以下是使用SwiftyJSON

的解决方案

if let path : String = NSBundle.mainBundle().pathForResource("filename", ofType: "json") {
    if let data = NSData(contentsOfFile: path) {

        let json = JSON(data: data)

    }
}

Answer 12

我提供了另一个答案，因为这里的所有答案都不适合从测试包中加载资源。如果您正在使用一个发出JSON的远程服务，并希望在不触及实际服务的情况下对结果进行单元测试，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，但获取测试包并加载文件的核心逻辑就是问题的答案。

Answer 13

以下代码对我有用。我正在使用 Swift 5

let path = Bundle.main.path(forResource: "yourJSONfileName", ofType: "json")
var jsonData = try! String(contentsOfFile: path!).data(using: .utf8)!

然后，如果您的“人员结构”（或类）是可解码的（及其所有属性），则只需执行以下操作：

let person = try! JSONDecoder().decode(Person.self, from: jsonData)

我避免使用所有错误处理代码，以使代码更清晰易懂。

Answer 14

最新的swift 3.0绝对正常工作

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
    }

Answer 15

简化Peter Kreinz提供的示例。适用于Swift 4.2。

扩展功能：

extension Decodable {
  static func parse(jsonFile: String) -> Self? {
    guard let url = Bundle.main.url(forResource: jsonFile, withExtension: "json"),
          let data = try? Data(contentsOf: url),
          let output = try? JSONDecoder().decode(self, from: data)
        else {
      return nil
    }

    return output
  }
}

示例模型：

struct Service: Decodable {
  let name: String
}

示例用法：

/// service.json
/// { "name": "Home & Garden" }

guard let output = Service.parse(jsonFile: "service") else {
// do something if parsing failed
 return
}

// use output if all good

该示例也适用于数组：

/// services.json
/// [ { "name": "Home & Garden" } ]

guard let output = [Service].parse(jsonFile: "services") else {
// do something if parsing failed
 return
}

// use output if all good

请注意，我们如何不提供任何不必要的泛型，因此我们无需转换解析结果。

Answer 16

迅速4：试用我的解决方案：

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
}

Decodable + 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)
    }
}

示例：

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")
*/

Answer 17

以最安全的方式更新了Swift 3

    private func readLocalJsonFile() {

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

        do {
            let jsonData = try Data(contentsOf: urlPath, options: .mappedIfSafe)

            if let jsonDict = try JSONSerialization.jsonObject(with: jsonData, options: .mutableContainers) as? [String: AnyObject] {

                if let personArray = jsonDict["person"] as? [[String: AnyObject]] {

                    for personDict in personArray {

                        for (key, value) in personDict {

                            print(key, value)
                        }
                        print("\n")
                    }
                }
            }
        }

        catch let jsonError {
            print(jsonError)
        }
    }
}

Answer 18

使用此通用功能

具有以下代码行：

func readJSONFromFile<T: Decodable>(fileName: String, type: T.Type) -> T? {
    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
}

此类型：

let model = readJSONFromFile(fileName: "Model", type: Model.self)

Answer 19

这适用于XCode 8.3.3

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)
        }
    }
}

Answer 20

//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)")
    }
}

Answer 21

Swift 4.1更新了Xcode 9.2

if let filePath = Bundle.main.path(forResource: "fileName", ofType: "json"), let data = NSData(contentsOfFile: filePath) {

     do {
      let json = try JSONSerialization.jsonObject(with: data as Data, options: JSONSerialization.ReadingOptions.allowFragments)        
        }
     catch {
                //Handle error
           }
 }

Answer 22

Based on Abhishek's answer, for iOS 8 this would be:

let masterDataUrl: NSURL = NSBundle.mainBundle().URLForResource("masterdata", withExtension: "json")!
let jsonData: NSData = NSData(contentsOfURL: masterDataUrl)!
let jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(jsonData, options: nil, error: nil) as! NSDictionary
var persons : NSArray = jsonResult["person"] as! NSArray

Answer 23

在清理和完善我的代码后，我找到了这两个函数，您可以将它们添加到您的项目中，并使用它们非常简洁快速地从 json 文件中读取并将数据转换为您想要的任何类型！

public func readDataRepresentationFromFile(resource: String, type: String) -> Data? {
    let filePath = Bundle.main.path(forResource: resource, ofType: type)
    
    if let path = filePath {
        let result = FileManager.default.contents(atPath: path)
        return result
    }
    return nil
}

然后在此功能的帮助下，您可以将数据转换为您想要的任何类型：

public func getObject<T: Codable>(of type: T.Type, from file: String) -> T?  {
    guard let data = readDataRepresentationFromFile(resource: file, type: "json") else {
        return nil
    }
    if let object = try? JSONDecoder().decode(type, from: data) {
        return object
    }
    return nil
}

此代码的应用示例：在代码中的任何位置调用这个函数，给它你的 json 文件的名称，这就是你所需要的！

func getInputDataFromSomeJson(jsonFileName: String) -> YourReqiuredOutputType? {
    return getObject(of: YourReqiuredOutputType.self, from: jsonFileName)
}

Answer 24

首先创建这样的Struc编码：

 var jzdosList = [JuzgadosList]()

现在声明变量

func getJsonFromDirectory() {

        if let path = Bundle.main.path(forResource: "juzgados", ofType: "json") {
            do {
                let data = try Data(contentsOf: URL(fileURLWithPath: path), options: .alwaysMapped)
                let jList = try JSONDecoder().decode([JuzgadosList].self, from: data)
                self.jzdosList = jList

                DispatchQueue.main.async() { () -> Void in
                    self.tableView.reloadData()
                }

            } catch let error {
                print("parse error: \(error.localizedDescription)")
            }
        } else {
            print("Invalid filename/path.")
        }
    }

从主目录读取

func getJsonFromUrl(){

        self.jzdosList.removeAll(keepingCapacity: false)

        print("Internet Connection Available!")

        guard let url = URL(string: "yourURL")  else { return }

        let request = URLRequest(url: url, cachePolicy: URLRequest.CachePolicy.reloadIgnoringLocalCacheData, timeoutInterval: 60.0)
        URLSession.shared.dataTask(with: request) { (data, response, err) in
            guard let data = data else { return }
            do {
                let jList = try JSONDecoder().decode([JuzgadosList].self, from: data)
                self.jzdosList = jList

                DispatchQueue.main.async() { () -> Void in
                    self.tableView.reloadData()
                }
            } catch let jsonErr {
                print("Error serializing json:", jsonErr)
            }
        }.resume()
    }

从网上阅读

{{1}}

Answer 25

Swift 5+

用你的结构体解码jsonData

if let jsonData = readFile(forName: <your file name>) {

do {
                let decodedData = try JSONDecoder().decode(<your struct name>.self, from: jsonData)
                return decodedData.<what you expect>
            } catch { print("JSON decode error") }
}

这将读取文件并返回 jsonData

<块引用>

如果您实际上在另一个包中（例如测试），请使用：
let bundlePath = Bundle(for: type(of: self)).path(forResource: name, ofType: "json")

private func readFile(forName name: String) -> Data? {
        do {

            if let bundlePath = Bundle.main.path(forResource: name, ofType: "json"),
                let jsonData = try String(contentsOfFile: bundlePath).data(using: .utf8) {
                return jsonData
            }
        } catch {
            print(error)
        }
        return nil
    }

Answer 26

对于那些希望在 Decodable 引发错误后在调试器 / lldb 中打印 JSON 数据的人，试试这个。

po try! JSONSerialization.jsonObject(with: data!, options: .mutableLeaves) as? Dictionary<String, Any>

Answer 27

使用JSON将4 Class转换为Decodable-适用于喜欢上课的人

如下定义类：

class People: Decodable {
  var person: [Person]?

  init(fileName : String){
    // url, data and jsonData should not be nil
    guard let url = Bundle.main.url(forResource: fileName, withExtension: "json") else { return }
    guard let data = try? Data(contentsOf: url) else { return }
    guard let jsonData = try? JSONDecoder().decode(People.self, from: data) else { return }

    // assigns the value to [person]
    person = jsonData.person
  }
}

class Person : Decodable {
  var name: String
  var age: String
  var employed: String
}

用法非常抽象：

let people = People(fileName: "people")
let personArray = people.person

如果需要，此People和Person类的允许方法，变量（属性）和方法也可以标记为private。

Answer 28

我也可能会推荐Ray Wenderlich的Swift JSON Tutorial（其中也涵盖了令人敬畏的SwiftyJSON替代方案，Gloss）。摘录（本身并没有完全回答海报，但是这个答案的附加价值就是链接，所以请不要这样做）：

在Objective-C中，解析和反序列化JSON非常简单：

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选项和类型安全[但作为] Swift 2.0的一部分，解析和反序列化JSON有点繁琐，guard语句被引入以帮助摆脱嵌套{{1} }声明：

if

当然，在XCode 8.x中，你只需双击空格键并说出＆＃34;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。＆＃34;

Answer 29

SWIFTYJSON VERSION SWIFT 3

func loadJson(fileName: String) -> JSON {

    var dataPath:JSON!

    if let path : String = Bundle.main.path(forResource: fileName, ofType: "json") {
        if let data = NSData(contentsOfFile: path) {
             dataPath = JSON(data: data as Data)
        }
    }
    return dataPath
}

Answer 30

我使用以下代码从项目目录中的FAQ-data.json文件中获取JSON 。

我正在使用Swift在Xcode 7.3中实现。

     func fetchJSONContent() {
            if let path = NSBundle.mainBundle().pathForResource("FAQ-data", ofType: "json") {

                if let jsonData = NSData(contentsOfFile: path) {
                    do {
                        if let jsonResult: NSDictionary = try NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.MutableContainers) as? NSDictionary {

                            if let responseParameter : NSDictionary = jsonResult["responseParameter"] as? NSDictionary {

                                if let response : NSArray = responseParameter["FAQ"] as? NSArray {
                                    responseFAQ = response
                                    print("response FAQ : \(response)")
                                }
                            }
                        }
                    }
                    catch { print("Error while parsing: \(error)") }
                }
            }
        }

override func viewWillAppear(animated: Bool) {
        fetchFAQContent()
    }

JSON文件的结构：

{
    "status": "00",
    "msg": "FAQ List ",
    "responseParameter": {
        "FAQ": [
            {                
                "question": “Question No.1 here”,
                "answer": “Answer goes here”,  
                "id": 1
            },
            {                
                "question": “Question No.2 here”,
                "answer": “Answer goes here”,
                "id": 2
            }
            . . .
        ]
    }
}

使用Swift读取JSON文件

30 个答案:

Swift 4.0：

Swift 5.1，Xcode 11

Swift 4.1更新了Xcode 9.2