优雅的判断网络超时,不要再用err.Error()判断里面有timeout了

系统库已经写好了判断超时的接口了，直接按下面调用就行额

package main

import (
    "log"
    "net"
    "net/http"
    "net/url"
    "time"
)

func main() {
    c, err := net.Dial("udp", "127.0.0.1:12345")
    if err != nil {
        log.Fatal(err)
    }
    c.SetDeadline(time.Now().Add(time.Second))
    var buf = make([]byte, 8)
    c.Write(buf)
    _, err = c.Read(buf)
    if err != nil {
        netErr, ok := err.(*net.OpError)
        if ok && netErr.Timeout() {
            log.Println("net timeout")
        }
    }

    req, err := http.NewRequest(http.MethodGet, "http://asdasd", nil)
    if err != nil {
        log.Fatal(err)
    }
    client := http.Client{Timeout: time.Second}
    _, err = client.Do(req)
    if err != nil {
        urlErr, ok := err.(*url.Error)
        if ok && urlErr.Timeout() {
            log.Println("http timeout")
        }
    }
}