go - 显示 URL 而非 Go 请求 GCP 响应的代码

Question

我很难在 Google Cloud Platform 中显示方向请求的结果。这是我尝试过的：

package main

import (
    "fmt"
    "net/http"
    "context"
    "io/ioutil"
    "google.golang.org/appengine"
    "google.golang.org/appengine/urlfetch"
)

const directionAPIKey = "MyAppKey"
const directionURL = "https://maps.googleapis.com/maps/api/directions/json?origin=%s&destination=%s&mode=%s&key=%s"

func main() {
    http.HandleFunc("/", handler)
}

func handler(w http.ResponseWriter, r *http.Request) {
    ctx := appengine.NewContext(r)
    direction, err := fetchDirection(ctx, r.FormValue("origin"), r.FormValue("destination"), r.FormValue("mode"))
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return
    }
    w.Header().Add("Content-Type", "application/json; charset=utf-8")
    w.Write(direction)
}

func fetchDirection(ctx context.Context, origin string, destination string, mode string) ([]byte, error) {
    client := urlfetch.Client(ctx)
    resp, err := client.Get(fmt.Sprintf(directionURL, origin, destination, mode, directionAPIKey))
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()
    return ioutil.ReadAll(resp.Body)
}

我成功部署了我的应用程序，但是，上面代码的结果是：

Get https://maps.googleapis.com/maps/api/directions/json?origin=&destination=&mode=&key=APIKey not an App Engine context

而不是请求的结果。这是来自浏览器的图像。我怎样才能得到想要的结果，而不仅仅是那个 URL？提前致谢。

标签： gogoogle-app-enginegoogle-cloud-platformgoogle-cloud-consolegoogle-app-engine-golang

Answer 1

我发现当您的 AppEngine 应用程序将运行时设置为 go111 并且应用程序导入任何“google.golang.org/appengine”包但应用程序不调用“ appengine.Main”</p>

method func main() {
    http.HandleFunc("/", handler)
    appengine.Main()
}