:art: #1554 优化小程序获取token逻辑，减少刷新请求次数

weixin-java-miniapp/src/main/java/cn/binarywang/wx/miniapp/api/impl/WxMaServiceImpl.java

@@ -116,6 +116,10 @@ public class WxMaServiceImpl implements WxMaService, RequestHttp<CloseableHttpCl
     Lock lock = this.getWxMaConfig().getAccessTokenLock();
     lock.lock();
     try {
+      if (!this.getWxMaConfig().isAccessTokenExpired() && !forceRefresh) {
+        return this.getWxMaConfig().getAccessToken();
+      }
+      
       String url = String.format(WxMaService.GET_ACCESS_TOKEN_URL, this.getWxMaConfig().getAppid(),
         this.getWxMaConfig().getSecret());
       try {