From b6762f11ef88412cfddc388d78f664a746d05906 Mon Sep 17 00:00:00 2001
From: yangyl12345 <yangyl971227@gmail.com>
Date: Mon, 25 Nov 2024 22:18:24 +0800
Subject: [PATCH 1/2] Update default_access_token.go
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

微信获取稳定版token，只有不等于空字符串的情况下才会返回access_token信息，未空的情况，继续调去微信服务
---
 credential/default_access_token.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/credential/default_access_token.go b/credential/default_access_token.go
index 00ad481..bcebb19 100644
--- a/credential/default_access_token.go
+++ b/credential/default_access_token.go
@@ -130,7 +130,9 @@ func (ak *StableAccessToken) GetAccessTokenContext(ctx context.Context) (accessT
 	// 先从cache中取
 	accessTokenCacheKey := fmt.Sprintf("%s_stable_access_token_%s", ak.cacheKeyPrefix, ak.appID)
 	if val := ak.cache.Get(accessTokenCacheKey); val != nil {
-		return val.(string), nil
+		if accessToken = val.(string); accessToken != "" {
+			return
+		}
 	}
 
 	// cache失效，从微信服务器获取

From a15ccac41eddddb82ca5edad744e851c32416274 Mon Sep 17 00:00:00 2001
From: w_yangyili <w_yangyili@xiwang.com>
Date: Tue, 26 Nov 2024 10:55:56 +0800
Subject: [PATCH 2/2] =?UTF-8?q?=E5=BE=AE=E4=BF=A1=E7=A8=B3=E5=AE=9A?=
 =?UTF-8?q?=E6=80=A7=E8=8E=B7=E5=8F=96=20access=5Ftoken=20=E6=8E=A5?=
 =?UTF-8?q?=E5=8F=A3=EF=BC=8C=E6=B7=BB=E5=8A=A0=E9=98=B2=E6=AD=A2=E5=B9=B6?=
 =?UTF-8?q?=E5=8F=91=E6=80=A7=E8=8E=B7=E5=8F=96=20access=5Ftoken=20?=
 =?UTF-8?q?=E5=92=8C=E5=A4=9A=E6=AC=A1=E5=BE=AE=E4=BF=A1=E6=9C=8D=E5=8A=A1?=
 =?UTF-8?q?=E8=8E=B7=E5=8F=96=E4=BB=A3=E7=A0=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 credential/default_access_token.go | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/credential/default_access_token.go b/credential/default_access_token.go
index bcebb19..ec88a89 100644
--- a/credential/default_access_token.go
+++ b/credential/default_access_token.go
@@ -101,10 +101,11 @@ func (ak *DefaultAccessToken) GetAccessTokenContext(ctx context.Context) (access
 // 不强制更新access_token,可用于不同环境不同服务而不需要分布式锁以及公用缓存，避免access_token争抢
 // https://developers.weixin.qq.com/miniprogram/dev/OpenApiDoc/mp-access-token/getStableAccessToken.html
 type StableAccessToken struct {
-	appID          string
-	appSecret      string
-	cacheKeyPrefix string
-	cache          cache.Cache
+	appID           string
+	appSecret       string
+	cacheKeyPrefix  string
+	cache           cache.Cache
+	accessTokenLock *sync.Mutex
 }
 
 // NewStableAccessToken new StableAccessToken
@@ -113,10 +114,11 @@ func NewStableAccessToken(appID, appSecret, cacheKeyPrefix string, cache cache.C
 		panic("cache is need")
 	}
 	return &StableAccessToken{
-		appID:          appID,
-		appSecret:      appSecret,
-		cache:          cache,
-		cacheKeyPrefix: cacheKeyPrefix,
+		appID:           appID,
+		appSecret:       appSecret,
+		cache:           cache,
+		cacheKeyPrefix:  cacheKeyPrefix,
+		accessTokenLock: new(sync.Mutex),
 	}
 }
 
@@ -135,6 +137,17 @@ func (ak *StableAccessToken) GetAccessTokenContext(ctx context.Context) (accessT
 		}
 	}
 
+	// 加上lock，是为了防止在并发获取token时，cache刚好失效，导致从微信服务器上获取到不同token
+	ak.accessTokenLock.Lock()
+	defer ak.accessTokenLock.Unlock()
+
+	// 双检，防止重复从微信服务器获取
+	if val := ak.cache.Get(accessTokenCacheKey); val != nil {
+		if accessToken = val.(string); accessToken != "" {
+			return
+		}
+	}
+
 	// cache失效，从微信服务器获取
 	var resAccessToken ResAccessToken
 	resAccessToken, err = ak.GetAccessTokenDirectly(ctx, false)