json - 尝试从 GitHub 按名称加载 JSON 格式的存储库列表

Question

我尝试执行 HTTP 请求，以 JSON 格式从 GitHub 获取存储库列表。

这是我的应用程序，它将包含存储库列表和搜索存储库名称的功能。

import Foundation

class NetworkService {

    private init() {}

    static let shared = NetworkService()

    func getData(matching query: String, completionHandler: @escaping (Any) -> ()) {
        let session = URLSession.shared
        var searchUrlComponents = URLComponents()
        searchUrlComponents.scheme = "https"
        searchUrlComponents.host = "api.github.com"
        searchUrlComponents.path = "search/repositories?"
        searchUrlComponents.queryItems = [URLQueryItem(name: "q", value: query)]
        let searchURL = searchUrlComponents.url!
        print(searchUrlComponents.url!
)

        session.dataTask(with: searchURL) { (data, response, error) in
            guard let data = data else { return }

            do {
                let json = try JSONSerialization.jsonObject(with: data, options: [])
                print(json)
            } catch {
                print(error)
            }
            }.resume()
    }
}

在这部分我遇到了错误。

我尝试不使用URLComponent，并得到相同的错误，代码如下所示:

import Foundation

class NetworkService {

    private init() {}

    static let shared = NetworkService()

    func getData(matching query: String, completionHandler: @escaping (Any) -> ()) {
        let session = URLSession.shared
        let searchURL = URL(string: "https://api.github.com/search/repositories?q={swift}")!
        print(searchURL)


        session.dataTask(with: searchURL) { (data, response, error) in
            guard let data = data else { return }

            do {
                let json = try JSONSerialization.jsonObject(with: data, options: [])
                print(json)
            } catch {
                print(error)
            }
            }.resume()
      }
    }

错误如下:

Fatal error: Unexpectedly found nil while unwrapping an Optional value

但是当我在浏览器中使用这样的 URL 发出请求时 ("https://api.github.com/search/repositories?q={swift}") 然后加载 JSON。

Answer 1

URLComponents 的路径必须以斜杠开头，并且不能以问号结尾

searchUrlComponents.path = "/search/repositories"

在第二个示例中，如果省略大括号，则 URL 有效

let searchURL = URL(string: "https://api.github.com/search/repositories?q=swift")!

原因是与浏览器不同，API URL(string: 不会隐式编码 URL