package main

import (
 "bufio"
 "fmt"
 "net/http"
 "os"
 "sync"
)

var (
 maxWorkers = 10
 wg         sync.WaitGroup
)

func worker(in <-chan string) {
 for url := range in {
  resp, err := http.Get(url)
  if err != nil {
   fmt.Printf("Failed to request %s\n", url)
  } else {
   defer resp.Body.Close()
   fmt.Printf("URL %s has been successfully requested\n", url)
  }
  wg.Done()
 }
}

func main() {
 file, err := os.Open("url.txt")
 if err != nil {
  fmt.Println("Failed to open file:", err)
  return
 }
 defer file.Close()

 // 创建一个带缓冲的通道
 urls := make(chan string, maxWorkers)

 // 启动goroutines处理请求
 for i := 0; i < maxWorkers; i++ {
  go worker(urls)
 }

 scanner := bufio.NewScanner(file)

 // 将URL发送给 goroutines 处理
 for scanner.Scan() {
  url := scanner.Text()
  wg.Add(1)
  urls <- url
 }

 close(urls)

 wg.Wait()
}