initial commit

.vscode/launch.json

+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch",
+            "type": "go",
+            "request": "launch",
+            "mode": "debug",
+            "remotePath": "",
+            "port": 2345,
+            "host": "127.0.0.1",
+            "program": "${fileDirname}",
+            "env": {},
+            "args": [],
+            "showLog": true
+        }
+    ]
+}

listen.go

+package main
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+)
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "Hi there, I love %s!", r.URL.Path[1:])
+	rq := r.URL.RawQuery
+	m, _ := url.ParseQuery(rq)
+	for index, element := range m {
+		fmt.Fprintf(w, "<br>%s => %s", index, element)
+	}
+	//      fmt.Fprintf(w, m["k"][0]);
+}
+
+func wechat_auth_setup_handler(w http.ResponseWriter, r *http.Request) {
+	rq := r.URL.RawQuery
+	m, _ := url.ParseQuery(rq)
+	fmt.Fprintf(w, m["echostr"][0])
+}
+
+func main() {
+	http.HandleFunc("/", handler)
+	http.HandleFunc("/api", wechat_auth_setup_handler)
+	//http.ListenAndServe("127.0.0.1:65500", nil)
+	http.ListenAndServe(":65500", nil)
+}

main.go

+//
+// {"access_token":"s0wf65p-KMzvYtH8qPu2qSX_EXLE2NaBgFHl7MZwedc7Kv_hdO0FG1QeUmBYJAGmQqJinPwFr67MRZwJee4rDnGVwhbuIfKs29N4ZJSXFP8fbAheuas08UuRe13UsdCtWSMcAFAGCW","expires_in":7200}
+//
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/http/httputil"
+	"time"
+)
+
+//SaveToPath : where the authtoken json file is stored
+const SaveToPath = "/tmp/wechat_hitxy_token"
+
+type authToken struct {
+	AccessToken string    `json:"access_token"`
+	ExpireIn    int64     `json:"expires_in"`
+	Time        time.Time `json:"created_at"`
+}
+
+func main2() {
+	e, _ := renewAuthtoken()
+	t, _ := readTokenFromFile("/tmp/wechat_hitxy_token")
+	fmt.Println(isAuthTokenExpired(t), e)
+}
+
+func debug(data []byte, err error) {
+	if err == nil {
+		fmt.Printf("%s\n\n", data)
+	} else {
+		log.Fatalf("%s\n\n", err)
+	}
+}
+
+func isAuthTokenExpired(t authToken) bool {
+	seconds := fmt.Sprintf("%ds", t.ExpireIn) //7200s
+	duration, _ := time.ParseDuration(seconds)
+	expire := t.Time.Add(duration)
+	return time.Now().After(expire)
+}
+
+func writeTokenToFile(body []byte, path string) {
+	log.Printf("writing authtoke to %s\r\n", path)
+	ioutil.WriteFile(path, body, 0600)
+}
+
+func readTokenFromFile(path string) (authToken, error) {
+	var m authToken
+	log.Printf("read authtoke from %s\r\n", path)
+	body, err := ioutil.ReadFile(path)
+	json.Unmarshal(body, &m)
+	return m, err
+}
+
+func renewAuthtoken() (authToken, error) {
+	//url := "http://vimeo.com/api/v2/brad/info.json"
+	url := "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=wx876e233fde456b7b&secret=4a91aa328569b10a9fb97adeb8b0af58"
+	var myClient = &http.Client{Timeout: 20 * time.Second}
+	r, err := myClient.Get(url)
+	if err != nil {
+		return authToken{}, err
+	}
+	defer r.Body.Close()
+
+	var t authToken
+	err = json.NewDecoder(r.Body).Decode(&t)
+
+	if err != nil {
+		return authToken{}, err
+	}
+
+	t.Time = time.Now()
+	b, _ := json.Marshal(&t)
+	writeTokenToFile(b, SaveToPath)
+	return t, nil
+}
+
+//debugged http response
+func dummy() {
+	var body []byte
+	var response *http.Response
+	var request *http.Request
+	url := "http://vimeo.com/api/v2/brad/info.json"
+
+	request, err := http.NewRequest("GET", url, nil)
+	if err == nil {
+		request.Header.Add("Content-Type", "application/json")
+		debug(httputil.DumpRequestOut(request, true))
+		response, err = (&http.Client{}).Do(request)
+	}
+
+	if err == nil {
+		defer response.Body.Close()
+		debug(httputil.DumpResponse(response, true))
+		body, err = ioutil.ReadAll(response.Body)
+		//json.NewDecoder(response.Body).Decode(m)
+	}
+
+	if err == nil {
+		writeTokenToFile(body, "/tmp/wechat_hitxy_token")
+		//m.Time = time.Now()
+	} else {
+		log.Fatalf("ERROR: %s", err)
+	}
+}