Golang网络连接异常处理技巧

resp, err := http.Get("http://example.com")
if err != nil {
    log.Printf("请求失败: %v", err)
    // 根据错误类型做不同处理
    return
}
defer resp.Body.Close()

if netErr, ok := err.(net.Error); ok {
    if netErr.Timeout() {
        log.Println("请求超时")
    }
    if netErr.Temporary() {
        log.Println("临时性错误，可尝试重试")
    }
}

client := &http.Client{
    Timeout: 10 * time.Second,
    Transport: &http.Transport{
        DialContext: (&net.Dialer{
            Timeout:   5 * time.Second,
            KeepAlive: 30 * time.Second,
        }).DialContext,
        TLSHandshakeTimeout:   5 * time.Second,
        ResponseHeaderTimeout: 5 * time.Second,
        ExpectContinueTimeout: 2 * time.Second,
    },
}

var resp *http.Response
var err error
for i := 0; i < 3; i++ {
resp, err = client.Get("http://example.com/api")
if err == nil {
break
}
if netErr, ok := err.(net.Error); ok && netErr.Temporary() {
    time.Sleep(time.Second << i) // 指数退避
    continue
}

break // 非临时错误，不再重试
}
if err != nil {
log.Fatalf("重试后仍失败: %v", err)
}

log.Printf("网络请求失败 [url=%s] [error=%v] [time=%s]",
    "http://example.com", err, time.Now())