修改微信扫码登录 access_token 问题

utility/mqtt/mqtt.go

@@ -0,0 +1,23 @@
+package mqtt
+
+// MqttClient 定义了通用 MQTT 客户端接口
+type MqttClient interface {
+	// Publish 发布消息到指定 topic
+	Publish(topic string, payload []byte) error
+	// Subscribe 订阅指定 topic，接收回调
+	Subscribe(topic string, handler func(topic string, payload []byte)) error
+}
+
+// 全局注册表
+var clients = make(map[string]MqttClient)
+
+// Register 注册一个 MQTT 客户端实现
+func Register(name string, client MqttClient) {
+	clients[name] = client
+}
+
+// GetClient 获取已注册的客户端
+func GetClient(name string) (MqttClient, bool) {
+	client, ok := clients[name]
+	return client, ok
+}