go - 使用Go显示代码而不是请求GCP响应的代码

Question

我很难在Google Cloud Platform中显示指示请求的结果。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)
}

我已经成功部署了我的应用程序，但是，以上代码的结果是:

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 image 。如何获得理想的结果，而不仅仅是该URL？提前致谢。

Answer 1

我found，当您的AppEngine应用程序的运行时设置为go111并且该应用程序导入了任何“google.golang.org/appengine”包但该应用程序未调用“appengine.Main”

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