使用 Go 發送異步 HTTP 請求

Others
,

做法

新增 main.go 檔。

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package main

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

func main() {
	var wg sync.WaitGroup
	urls := []string{
		"https://json.epoch.tw/api/records/GELe31Mb69",
		"https://json.epoch.tw/api/records/KGRb4x1bBL",
		"https://json.epoch.tw/api/records/qM7e5yBe2v",
	}

	// 建立 channel 用來傳遞 API 的回應
	responses := make(chan *http.Response)

	// 遍歷 urls 並平行發送 HTTP 請求
	for _, url := range urls {
		wg.Add(1)
		go func(url string) {
			defer wg.Done()

			resp, err := http.Get(url)
			if err != nil {
				fmt.Println(err)
				return
			}

			responses <- resp
		}(url)
	}

	// 當所有 goroutine 都完成時，關閉 channel
	go func() {
		wg.Wait()
		close(responses)
	}()

	// 遍歷 API 的回應並印出結果
	for resp := range responses {
		fmt.Println("Response received:", resp.Status)
	}
}

執行程式。

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go run main.go

輸出如下：

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Response received: 200 OK
Response received: 200 OK
Response received: 200 OK