✨ 逻辑优化。

mica-mqtt-core/src/main/java/net/dreamlu/iot/mqtt/core/client/MqttClient.java

@@ -469,11 +469,14 @@ public final class MqttClient {
 	 * @return 是否停止成功
 	 */
 	public boolean stop() {
-		// 先断开连接
+		// 1. 先停止 ack 服务
+		this.ackService.stop();
+		// 2. 断开连接
 		this.disconnect();
+		// 3. 停止 tio
 		boolean result = tioClient.stop();
 		logger.info("MqttClient stop result:{}", result);
-		this.ackService.stop();
+		// 4. 清理 session
 		this.clientSession.clean();
 		return result;
 	}

mica-mqtt-core/src/main/java/net/dreamlu/iot/mqtt/core/server/MqttServer.java

@@ -353,6 +353,9 @@ public final class MqttServer {
 	 * @return 是否停止
 	 */
 	public boolean stop() {
+		// 先停止 ack 服务
+		this.ackService.stop();
+		// 再停止服务
 		boolean result = this.tioServer.stop();
 		logger.info("Mqtt tcp server stop result:{}", result);
 		if (webServer != null) {
@@ -364,7 +367,6 @@ public final class MqttServer {
 		} catch (Throwable e) {
 			logger.error("MqttServer stop session clean error.", e);
 		}
-		this.ackService.stop();
 		return result;
 	}