通过 Codable 解析 JSON 到数组

Question

我关注JSON:

[
{
 "id": 1,
 "type": "Feature",
 "geometry": {
     "type": "Point",
     "coordinates": [
         37.5741167,
         55.7636592
     ]
 },
 "properties": {
     "hintContent": "переулок Волков, 13с1",
     "balloonContentHeader": "переулок Волков, 13с1"
 }
]

我正在尝试使用 JSON解码器：

struct Point : Codable {
    let id: Int
    let type: String
    let properties: Properties
}
struct Properties : Codable {
    let hintContent: String
    let balloonContentHeader: String
}
struct Points : Codable {
    var data : [Point]
}



func parse(fileName: String) {

    let url = Bundle.main.url(forResource: fileName, withExtension: "json")
    let data = try? Data(contentsOf: url!)
    if let jsonPoints = try? JSONDecoder().decode([Point].self, from: data!) {
        print(jsonPoints)
    }
}

怎么了？

Answer 1

确保你的 JSON 是有效的——这个缺少 }。
将您的（有效）JSON 粘贴到 app.quicktype.io 中以生成模型，即。确保您的模型与 JSON 匹配。如果您的 JSON 无效，该网站也会向您发出警告。
始终使用 do/try/catch 而不是 try? 以便在 JSON 解码失败时可以得到有意义的错误。


let data = """
[
{
 "id": 1,
 "type": "Feature",
 "geometry": {
     "type": "Point",
     "coordinates": [
         37.5741167,
         55.7636592
     ]
 },
 "properties": {
     "hintContent": "t",
     "balloonContentHeader": "t"
 }
}
]
""".data(using: .utf8)

struct Point: Codable {
    let id: Int
    let type: String
    let geometry: Geometry
    let properties: Properties
}

// MARK: - Geometry
struct Geometry: Codable {
    let type: String
    let coordinates: [Double]
}

// MARK: - Properties
struct Properties: Codable {
    let hintContent, balloonContentHeader: String
}

func parse(fileName: String) {
    do {
        let jsonPoints = try JSONDecoder().decode([Point].self, from: data!)
        print(jsonPoints)
    } catch {
        print(error)
    }
    
}

如果没有调整后的 JSON，您的原始代码将在 catch 块中生成此错误：

The given data was not valid JSON....Badly formed object around character 224.

通过 Codable 解析 JSON 到数组

Parsing of JSON by Codable to array

json

swift

codable