将获取AccessToken和jsTicket单独抽象为interface

credential/default_js_ticket.go

@@ -0,0 +1,80 @@
+package credential
+
+import (
+	"encoding/json"
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/silenceper/wechat/v2/cache"
+	"github.com/silenceper/wechat/v2/util"
+)
+
+//获取ticket的url
+const getTicketURL = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=%s&type=jsapi"
+
+//DefaultJsTicket 默认获取js ticket方法
+type DefaultJsTicket struct {
+	appID          string
+	cacheKeyPrefix string
+	cache          cache.Cache
+	//jsAPITicket 读写锁 同一个AppID一个
+	jsAPITicketLock *sync.Mutex
+}
+
+//NewDefaultJsTicket new
+func NewDefaultJsTicket(appID string, cacheKeyPrefix string, cache cache.Cache) JsTicketHandle {
+	return &DefaultJsTicket{
+		appID:           appID,
+		cache:           cache,
+		cacheKeyPrefix:  cacheKeyPrefix,
+		jsAPITicketLock: new(sync.Mutex),
+	}
+}
+
+// ResTicket 请求jsapi_tikcet返回结果
+type ResTicket struct {
+	util.CommonError
+
+	Ticket    string `json:"ticket"`
+	ExpiresIn int64  `json:"expires_in"`
+}
+
+//GetTicket 获取jsapi_ticket
+func (js *DefaultJsTicket) GetTicket(accessToken string) (ticketStr string, err error) {
+	js.jsAPITicketLock.Lock()
+	defer js.jsAPITicketLock.Unlock()
+
+	//先从cache中取
+	jsAPITicketCacheKey := fmt.Sprintf("%s_jsapi_ticket_%s", js.cacheKeyPrefix, js.appID)
+	val := js.cache.Get(jsAPITicketCacheKey)
+	if val != nil {
+		ticketStr = val.(string)
+		return
+	}
+	var ticket ResTicket
+	ticket, err = GetTicketFromServer(accessToken)
+	if err != nil {
+		return
+	}
+	expires := ticket.ExpiresIn - 1500
+	err = js.cache.Set(jsAPITicketCacheKey, ticket.Ticket, time.Duration(expires)*time.Second)
+	ticketStr = ticket.Ticket
+	return
+}
+
+//GetTicketFromServer 从服务器中获取ticket
+func GetTicketFromServer(accessToken string) (ticket ResTicket, err error) {
+	var response []byte
+	url := fmt.Sprintf(getTicketURL, accessToken)
+	response, err = util.HTTPGet(url)
+	err = json.Unmarshal(response, &ticket)
+	if err != nil {
+		return
+	}
+	if ticket.ErrCode != 0 {
+		err = fmt.Errorf("getTicket Error : errcode=%d , errmsg=%s", ticket.ErrCode, ticket.ErrMsg)
+		return
+	}
+	return
+}