错误：使用Java连接Google Cloud Storage时=> java.net.UnknownHostException：oauth2.googleapis.com

Question

使用Java库连接到Google Cloud Storage时，出现以下异常：

1. 原因：java.net.UnknownHostException：oauth2.googleapis.com
2. 原因：java.io.IOException：获取服务帐户的访问令牌时出错：oauth2.googleapis.com

我们已经创建了Google Cloud Storage服务帐户Project，还下载了JSON文件。

下面是代码段：

struct Movie: Codable
{
   let trackId: Int
   let trackName: String
   let trackGenre: String
   let trackPrice: Int?
   let longDescription: String

   init(trackId: Int, trackName: String, trackGenre: String, 
   trackPrice: 
   Int?, /*trackImage: Thumbnail,*/ longDescription: String)
   {
    self.trackId = trackId
    self.trackName = trackName
    self.trackGenre = trackGenre
    self.trackPrice = trackPrice ?? 0
    self.longDescription = longDescription
    //self.trackImage = trackImage //TODO: thumbnail: mapp url from json
   }

  private enum MovieCodingKeys: String, CodingKey
  {
    case trackId
    case trackName
    case trackGenre = "primaryGenreName"
    case trackPrice
    //case trackImage
    case longDescription
  }

  init(from decoder: Decoder) throws
  {
    let container = try decoder.container(keyedBy: MovieCodingKeys.self)

    trackId = try container.decode(Int.self, forKey: .trackId)
    trackName = try container.decode(String.self, forKey: .trackName)
    trackGenre = try container.decode(String.self, forKey: .trackGenre)
    trackPrice = try container.decode(Int?.self, forKey: .trackPrice)
    longDescription = try container.decode(String.self, forKey: .longDescription)
  }
}

Answer 1

这可能是互联网的要求。

尝试：Android Studio：<uses-permission android:name="android.permission.INTERNET" />在Android清单上

Xamarin：

<uses-permission android:name="android.permission.INTERNET"></uses-permission>
         <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

在Android清单上