实现access_token获取

context/access_token.go

@@ -0,0 +1,71 @@
+package context
+
+import (
+	"encoding/json"
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/silenceper/wechat/util"
+)
+
+const (
+	//AccessTokenURL 获取access_token的接口
+	AccessTokenURL = "https://api.weixin.qq.com/cgi-bin/token"
+)
+
+//ResAccessToken struct
+type ResAccessToken struct {
+	ErrorCode int32  `json:"errcode"`
+	ErrorMsg  string `json:"errmsg"`
+
+	AccessToken string `json:"access_token"`
+	ExpiresIn   int32  `json:"expires_in"`
+}
+
+//SetAccessTokenLock 设置读写锁（一个appID一个读写锁）
+func (ctx *Context) SetAccessTokenLock(l *sync.RWMutex) {
+	ctx.accessTokenLock = l
+}
+
+//GetAccessToken 获取access_token
+func (ctx *Context) GetAccessToken() (accessToken string, err error) {
+	ctx.accessTokenLock.Lock()
+	defer ctx.accessTokenLock.Unlock()
+
+	accessTokenCacheKey := fmt.Sprintf("access_token_%s", ctx.AppID)
+	val := ctx.Cache.Get(accessTokenCacheKey)
+	if val != nil {
+		accessToken = val.(string)
+		return
+	}
+
+	//从微信服务器获取
+	var resAccessToken ResAccessToken
+	resAccessToken, err = ctx.GetAccessTokenFromServer()
+	if err != nil {
+		return
+	}
+
+	accessToken = resAccessToken.AccessToken
+	return
+}
+
+//GetAccessTokenFromServer 强制从微信服务器获取token
+func (ctx *Context) GetAccessTokenFromServer() (resAccessToken ResAccessToken, err error) {
+	url := fmt.Sprintf("%s?grant_type=client_credential&appid=%s&secret=%s", AccessTokenURL, ctx.AppID, ctx.AppSecret)
+	var body []byte
+	body, err = util.HTTPGet(url)
+	err = json.Unmarshal(body, &resAccessToken)
+	if err != nil {
+		return
+	}
+	if resAccessToken.ErrorMsg != "" {
+		err = fmt.Errorf("get access_token error : errcode=%v , errormsg=%v", resAccessToken.ErrorCode, resAccessToken.ErrorMsg)
+		return
+	}
+
+	accessTokenCacheKey := fmt.Sprintf("access_token_%s", ctx.AppID)
+	err = ctx.Cache.Set(accessTokenCacheKey, resAccessToken.AccessToken, time.Duration(resAccessToken.ExpiresIn)-1500/time.Second)
+	return
+}

context/context.go

@@ -1,6 +1,11 @@
 package context
 
-import "net/http"
+import (
+	"net/http"
+	"sync"
+
+	"github.com/silenceper/wechat/cache"
+)
 
 //Context struct
 type Context struct {
@@ -9,12 +14,13 @@ type Context struct {
 	Token          string
 	EncodingAESKey string
 
+	Cache cache.Cache
+
 	Writer  http.ResponseWriter
 	Request *http.Request
-}
-
-func (ctx *Context) getAccessToken() {
 
+	//accessTokenLock 读写锁 同一个AppID一个
+	accessTokenLock *sync.RWMutex
 }
 
 // Query returns the keyed url query value if it exists