doulai8405 2017-04-25 08:47
浏览 84
已采纳

如何在Golang中捕获特定错误

For example, I am using one golang standard library function as:

func Dial(network, address string) (*Client, error)

This function may return errors, and I just care about errors which report "connection lost" or "connection refused", then do some code to fix these.
It seems like:

client, err := rpc.Dial("tcp", ":1234")  
if err == KindOf(ConnectionRefused) {
  // do something
}

What's more, how to get all the errors a specific standard library function may return?

  • 写回答

1条回答 默认 最新

  • douyaju4259 2017-04-25 09:06
    关注

    There's no standard way to do this.

    The most obvious way, which should only be used if no other method is available, is to compare the error string against what you expect:

    if err.Error() == "connection lost" { ... }
    

    Or perhaps more robust in some situations:

    if strings.HasSuffix(err.Error(), ": connection lost") { ... }
    

    But many libraries will return specific error types, which makes this much easier.

    In your case, what's relevant are the various error types exported by the net package: AddrError, DNSConfigError, DNSError, Error, etc.

    You probably care most about net.Error, which is used for network errors. So you could check thusly:

    if _, ok := err.(net.Error); ok {
        // You know it's a net.Error instance
        if err.Error() == "connection lost" { ... }
    }
    

    What's more, how to get all the errors a specific standard library function may return?

    The only fool-proof way to do this is to read the source for the library. Before going to that extreme, a first step is simply to read the godoc, as in the case of the net package, the errors are pretty well documented.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥15 Cesm如何关闭不用的模块呢
  • ¥15 vue2两层数据导出为excle
  • ¥15 有人能帮我做一下这个项目吗
  • ¥15 网络上传速率比下载速率高
  • ¥15 (标签-游戏|关键词-网页游戏)
  • ¥15 这个咋搞🥹可能需要手把手教
  • ¥15 RFID标签芯片ROCKY100配置成SPI主机问题
  • ¥15 接口和关键字的问题,多选
  • ¥15 yolov5s模型下载就卡住,没有运行结果
  • ¥20 androidstudio工具问题