GoRoutines高性能同时进行多个Api调用实现

// Auth: janrs.com
package main
import "fmt"
import "net/http"
func main() {
	links := []string{
		"https://github.com/fabpot",
		"https://github.com/andrew",
		"https://github.com/taylorotwell",
		"https://github.com/egoist",
		"https://github.com/HugoGiraudel",
	}
	checkUrls(links)
}
func checkUrls(urls []string) {
	for _, link := range urls {
		checkUrl(link)
	}
}
func checkUrl(url string) {
	_, err := http.Get(url)
	if err != nil {
		fmt.Println("We could not reach:", url)
	} else {
		fmt.Println("Success reaching the website:", url)
	}
}

import (
	"fmt"
	"net/http"
	"sync"
)
func main() {
	links := []string{
		"https://github.com/fabpot",
		"https://github.com/andrew",
		"https://github.com/taylorotwell",
		"https://github.com/egoist",
		"https://github.com/HugoGiraudel",
	}
	checkUrls(links)
}
func checkUrls(urls []string) {
	c := make(chan string)
	var wg sync.WaitGroup
	for _, link := range urls {
		wg.Add(1)   // 这告诉wg，现在这里有一个待处理的操作。
		go checkUrl(link, c, &wg)
	}
	go func() {
		wg.Wait()	// 这将阻止Goroutine，直到WaitGroup计数器为零。#janrs.com
		close(c)    // 通道需要被关闭，否则下面的循环将永远持续下去
	}() 
    // 这个简略的循环是一个无休止的循环的语法糖，它只是在等待结果通过'c'通道进入。
	for msg := range c {
		fmt.Println(msg)
	}
}
func checkUrl(url string, c chan string, wg *sync.WaitGroup) {
	defer (*wg).Done()
	_, err := http.Get(url)
	if err != nil {
		c <- "#janrs.com#We could not reach:" + url    // 将结果输入通道
	} else {
		c <- "Success reaching the website:" + url    // 将结果输入通道
	}
}