ApsaraMQ for MQTT:Exportar eventos de status do cliente

package com.aliyun.openservices.lmq.example.demo;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.aliyun.openservices.ons.api.Action;
import com.aliyun.openservices.ons.api.ConsumeContext;
import com.aliyun.openservices.ons.api.Consumer;
import com.aliyun.openservices.ons.api.Message;
import com.aliyun.openservices.ons.api.MessageListener;
import com.aliyun.openservices.ons.api.ONSFactory;
import com.aliyun.openservices.ons.api.PropertyKeyConst;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

public class MQTTClientStatusNoticeProcessDemo {
    public static void main(String[] args) {
        // Initialize an ApsaraMQ for RocketMQ consumer to receive status notifications.
        Properties properties = new Properties();

        // The RocketMQ consumer group ID (different from the ApsaraMQ for MQTT group ID).
        properties.setProperty(PropertyKeyConst.GROUP_ID, "<your-rocketmq-group-id>");

        // AccessKey pair. Get these from the RAM console.
        properties.put(PropertyKeyConst.AccessKey, "<your-access-key>");
        properties.put(PropertyKeyConst.SecretKey, "<your-secret-key>");

        // TCP endpoint of the ApsaraMQ for RocketMQ instance.
        properties.put(PropertyKeyConst.NAMESRV_ADDR, "<your-rocketmq-endpoint>");

        // The RocketMQ topic that receives MQTT client status notifications.
        // Create this topic in the ApsaraMQ for RocketMQ console beforehand.
        final String parentTopic = "GID_XXXX_MQTT";

        // In production, use an external store (database or Redis) to persist status data
        // across application restarts.
        MqttClientStatusStore mqttClientStatusStore = new MemoryHashMapStoreImpl();

        Consumer consumer = ONSFactory.createConsumer(properties);

        // Subscribe to "connect" and "tcpclean" events only.
        consumer.subscribe(parentTopic, "connect||tcpclean",
            new MqttClientStatusNoticeListener(mqttClientStatusStore));
        consumer.start();

        // Poll the status of a specific client.
        String clientId = "GID_XXXXxXX@@@XXXXX";
        while (true) {
            System.out.println("Client online: " + checkClientOnline(clientId, mqttClientStatusStore));
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * Processes incoming status notifications and maintains the channel-event map.
     *
     * In a multi-server deployment, store client status in a shared external store
     * (database or Redis). Implement idempotent consumption to handle duplicate messages.
     */
    static class MqttClientStatusNoticeListener implements MessageListener {
        private MqttClientStatusStore mqttClientStatusStore;

        public MqttClientStatusNoticeListener(
            MqttClientStatusStore mqttClientStatusStore) {
            this.mqttClientStatusStore = mqttClientStatusStore;
        }

        @Override
        public Action consume(Message message, ConsumeContext context) {
            try {
                JSONObject msgBody = JSON.parseObject(new String(message.getBody()));
                System.out.println(msgBody);
                String eventType = msgBody.getString("eventType");
                String clientId = msgBody.getString("clientId");
                String channelId = msgBody.getString("channelId");
                ClientStatusEvent event = new ClientStatusEvent();
                event.setChannelId(channelId);
                event.setClientIp(msgBody.getString("clientIp"));
                event.setEventType(eventType);
                event.setTime(msgBody.getLong("time"));

                // Store the new event.
                mqttClientStatusStore.addEvent(clientId, channelId, eventType, event);

                // Read the event list for this connection.
                Set<ClientStatusEvent> events = mqttClientStatusStore.getEvent(clientId, channelId);
                if (events == null || events.isEmpty()) {
                    return Action.CommitMessage;
                }

                // If both connect and tcpclean events exist for this channelId,
                // the connection is closed. Clean up the entry.
                boolean findOnlineEvent = false;
                boolean findOfflineEvent = false;
                for (ClientStatusEvent clientStatusEvent : events) {
                    if (clientStatusEvent.isOnlineEvent()) {
                        findOnlineEvent = true;
                    } else {
                        findOfflineEvent = true;
                    }
                }
                if (findOnlineEvent && findOfflineEvent) {
                    mqttClientStatusStore.deleteEvent(clientId, channelId);
                }
                return Action.CommitMessage;
            } catch (Throwable e) {
                e.printStackTrace();
            }
            return Action.ReconsumeLater;
        }
    }

    /**
     * Checks whether the client has an active TCP connection.
     *
     * Logic:
     * 1. If the channel map is empty, the client is offline.
     * 2. If any channelId has only a connect event (no tcpclean), the client is online.
     * 3. If all channelIds have both connect and tcpclean events, the client is offline.
     */
    public static boolean checkClientOnline(String clientId,
        MqttClientStatusStore mqttClientStatusStore) {
        Map<String, Set<ClientStatusEvent>> channelMap =
            mqttClientStatusStore.getEventsByClientId(clientId);
        if (channelMap == null) {
            return false;
        }
        for (Set<ClientStatusEvent> events : channelMap.values()) {
            boolean findOnlineEvent = false;
            boolean findOfflineEvent = false;
            for (ClientStatusEvent event : events) {
                if (event.isOnlineEvent()) {
                    findOnlineEvent = true;
                } else {
                    findOfflineEvent = true;
                }
            }
            if (findOnlineEvent & !findOfflineEvent) {
                return true;
            }
        }
        return false;
    }

}