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。
首先像这样创建一个可编码的Struc:
struct JuzgadosList : Codable {
var CP : Int
var TEL : String
var LOCAL : String
var ORGANO : String
var DIR : String
}
现在声明变量
var jzdosList = [JuzgadosList]()
从主目录读取
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.")
}
}
网上阅读
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()
}
这里还有一个答案??
好的。坚持住!之前所有的答案都是关于使用JSONSerialization，或返回nil，或忽略错误。
有什么不同
“我的解决方案”(不是真的我的解决方案，这是上述解决方案的混合)包含:
返回值的现代方法:Result<Value,Error>(返回值或错误)
避免使用空值
包含一个稍微详细的错误
使用扩展有漂亮/直观的界面:
提供了选择包的可能性
细节
Xcode 14
斯威夫特5.6.1
解决方案1。JSON文件->可解码
enum JSONParseError: Error {
case fileNotFound
case dataInitialisation(error: Error)
case decoding(error: Error)
}
extension Decodable {
static func from(localJSON filename: String,
bundle: Bundle = .main) -> Result<Self, JSONParseError> {
guard let url = bundle.url(forResource: filename, withExtension: "json") else {
return .failure(.fileNotFound)
}
let data: Data
do {
data = try Data(contentsOf: url)
} catch let error {
return .failure(.dataInitialisation(error: error))
}
do {
return .success(try JSONDecoder().decode(self, from: data))
} catch let error {
return .failure(.decoding(error: error))
}
}
}
方案一用途
struct Model: Decodable {
let uuid: String
let name: String
}
switch Model.from(localJSON: "myjsonfile") {
case .success(let value):
print(value)
case .failure(let error):
print(error)
}
解决方案2。JSON文件->字典
extension Dictionary where Key == String, Value == Any {
enum JSONParseError: Error {
case fileNotFound(filename: String)
case dataInitialisation(Error)
case jsonSerialization(Error)
case mappingFail(value: Any, toType: Any)
}
static func from(JSONfile url: URL) -> Result<Self, JSONParseError> {
let data: Data
do {
data = try Data(contentsOf: url)
} catch let error {
return .failure(.dataInitialisation(error))
}
let jsonObject: Any
do {
jsonObject = try JSONSerialization.jsonObject(with: data, options: .mutableLeaves)
} catch let error {
return .failure(.jsonSerialization(error))
}
guard let jsonResult = jsonObject as? Self else {
return .failure(.mappingFail(value: jsonObject, toType: Self.Type.self))
}
return .success(jsonResult)
}
static func from(localJSONfile name: String) -> Result<Self, JSONParseError> {
let fileType = "json"
let fullFileName = name + (name.contains(fileType) ? "" : ".\(fileType)")
guard let path = Bundle.main.path(forResource: fullFileName, ofType: "") else {
return .failure(.fileNotFound(filename: fullFileName))
}
return from(JSONfile: URL(fileURLWithPath: path))
}
}
方案二使用
switch [String: Any].from(localJSONfile: "file.json") {
// OR switch [String: Any].from(localJSONfile: "file.json") {
// OR switch [String: Any].from(JSONfile: url) {
case let .success(dictionary):
print(dictionary)
case let .failure(error):
print("ERROR: \(error)")
}
我使用下面的代码从FAQ-data中获取JSON。Json文件存在于项目目录中。
我在Xcode 7.3中使用Swift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
}
. . .
]
}
}
