package main

import (
	"fmt"
	"io"
	"net/http"
	"sync"
)

type Downloader interface {
	Download(url string)
}

type Task struct{}

func (t *Task) Download(url string) {
	fmt.Println("Downloading:", url)
	resp, err := http.Get(url)
	if err != nil {
		fmt.Println("Error:", err)
		return
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		fmt.Println("Downloaded:", resp.Status)
		return
	} else {
		body, err := io.ReadAll(resp.Body)
		if err != nil {
			fmt.Println("Error:", err)
			return
		}
		fmt.Println(string(body))
	}
}

func main() {
	// 多个url
	urls := []string{
		"https://www.cnblogs.com/apachecn/p/19074830",
		"https://www.cnblogs.com/apachecn/p/19074830",
	}

	wg := sync.WaitGroup{}

	for _, url := range urls {
		wg.Add(1)
		go func(url string) {
			defer wg.Done()
			t := &Task{}
			t.Download(url)
		}(url)
	}

	wg.Wait()
	fmt.Println("all tasks done")
}