[英]How to parse nested json? Swift
我有一个本地 json 字符串,我正在尝试解析它,但是当我尝试这样做时,我不断收到错误消息。 我也在嵌套字典中看到了这个错误,但找不到错误。 下面是json字符串
let jsonNestedString = "{\"meta\":{\"page\":1,\"total_pages\":4,\"per_page\":10,\"total_records\" : 38}, \"reweries\":[\"id\":1234,\"name\":\"saintArnold\"},{\"id\":52892,\"name\":\"buffalo bayou\"]}"
我正在通过 Codable 执行此过程,下面是我为此创建的结构
struct PagedBreweries:Codable{
struct Meta:Codable{
let page : Int
let total_pages:Int
let per_page:Int
let total_records: Int
enum CodingKeys: String, CodingKey{
case page
case total_pages
case per_page
case total_records
}
}
struct Brewery :Codable{
let id:Int
let name:String
}
let meta:Meta
let breweries :[Brewery]
}
然后将此数据解析为如下函数
func jsonNested(){
let jsonData = jsonNestedString.data(using: .utf8)
let decoder = JSONDecoder()
let data = try! decoder.decode(PagedBreweries.Meta.self, from: jsonData!)
print(data)
}
当我尝试构建时,我得到的错误出现在尝试中! 解码器.解码
命令,错误是
线程 1:致命错误:“尝试!” 表达式意外引发错误:Swift.DecodingError.keyNotFound(CodingKeys(stringValue: "page", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: \\") page\\", intValue: nil) (\\"page\\").",underlyingError: nil))
任何人都可以提供解决方案吗? 提前致谢
正确的json
{
"meta": {
"page": 1,
"total_pages": 4,
"per_page": 10,
"total_records": 38
},
"reweries": [{
"id": 1234,
"name": "saintArnold"
},
{
"id": 52892,
"name": "buffalo bayou"
}
]
}
struct Root: Codable {
let meta: Meta
let reweries: [Rewery]
}
struct Meta: Codable {
let page, totalPages, perPage, totalRecords: Int
enum CodingKeys: String, CodingKey { // snake case may be used
case age = "page"
case totalPages = "total_pages"
case perPage = "per_page"
case totalRecords = "total_records"
}
}
struct Rewery: Codable {
let id: Int
let name: String
}
let jsonNestedString = """
{\"meta\":{\"page\":1,\"total_pages\":4,\"per_page\":10,\"total_records\":38}, \"reweries\":[{\"id\":1234,\"name\":\"saintArnold\"},{\"id\":52892,\"name\":\"buffalo bayou\"}]}
"""
// or
let jsonNestedString = """
{
"meta": {
"page": 1,
"total_pages": 4,
"per_page": 10,
"total_records": 38
},
"reweries": [{
"id": 1234,
"name": "saintArnold"
},
{
"id": 52892,
"name": "buffalo bayou"
}
]
}
"""
do {
let jsonData = jsonNestedString.data(using: .utf8)
let decoder = JSONDecoder()
let data = try decoder.decode(Root.self, from: jsonData!)
print(data)
} catch {
print(error)
}
JSON 已损坏,您正在解码错误的根对象。
这是使用您的结构解码并符合 Swift 命名约定的正确JSON
let jsonNestedString = """
{"meta":{"page":1,"total_pages":4,"per_page":10,"total_records" : 38}, "breweries":[{"id":1234,"name":"saintArnold"},{"id":52892,"name":"buffalo bayou"}]}
"""
struct PagedBreweries : Codable {
struct Meta : Codable {
let page : Int
let totalPages:Int
let perPage:Int
let totalRecords: Int
}
struct Brewery : Codable {
let id:Int
let name:String
}
let meta:Meta
let breweries :[Brewery]
}
func jsonNested(){
let jsonData = Data(jsonNestedString.utf8)
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let data = try! decoder.decode(PagedBreweries.self, from: jsonData)
print(data)
}
jsonNested()
// Printed result:
// PagedBreweries(meta: __lldb_expr_1.PagedBreweries.Meta(page: 1, totalPages: 4, perPage: 10, totalRecords: 38), breweries: [__lldb_expr_1.PagedBreweries.Brewery(id: 1234, name: "saintArnold"), __lldb_expr_1.PagedBreweries.Brewery(id: 52892, name: "buffalo bayou")])
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.