package main
import (
"fmt"
"io"
"io/ioutil"
"net/http"
"time"
)
var https = []string{"https://www.baidu.com", "https://github.com/Addision"}
func main() {
start := time.Now()
ch := make(chan string) //创建一个字符串通道
for _, url := range https {
fmt.Println("url ===", url)
go fetch(url, ch) //go 创建协程
}
for range https {
fmt.Println(<-ch) //从通道读取信息
}
fmt.Printf("%.2fs elapsed\n", time.Since(start).Seconds())
}
func fetch(url string, ch chan<- string) {
start := time.Now()
resp, err := http.Get(url)
if err != nil {
ch <- fmt.Sprint(err)
return
}
nbytes, err := io.Copy(ioutil.Discard, resp.Body)
resp.Body.Close()
if err != nil {
ch <- fmt.Sprintf("while reading %s: %v", url, err)
return
}
secs := time.Since(start).Seconds()
ch <- fmt.Sprintf("%.2fs %7d %s", secs, nbytes, url) //将格式化信息写入通道
}
go语言使用go 关键字创建协程并发处理信息
make 创建 chan 通道,进行信息传递,如果ch 通道没有消息,go会一直阻塞
ch <- fmt.Sprintf("while reading %s: %v", url, err) 向通道写东西
<- ch 从通道读取消息