将MQTT数据存储到Mongo数据库中

Question

我写了一个连接到MQTT Broker的程序，并将每个MQTT消息存储到Mongo数据库。它运作正常，但我真的不确定我是否以正确的方式完成了它。它打开了许多与mongo服务器的连接。

以下是代码：

public class MqttConnection {

private static final String BROKER_IP = Preferences.getProperty("mqttbroker-ip");
private static final String BROKER_PORT = Preferences.getProperty("mqttbroker-port");
private static final String BROKER_URI = "tcp://" + BROKER_IP + ":" + BROKER_PORT;

private static final String CLIENT_ID = Preferences.getProperty("mqttbroker-clientid");

private static final String USERNAME = Preferences.getProperty("mqttbroker-username");
private static final String PASSWORD = Preferences.getProperty("mqttbroker-password");

private static final String TOPIC = Preferences.getProperty("mqttbroker-topic");

private static final SimpleDateFormat SDF = new SimpleDateFormat("YYYYMMddHH:mm:ss");

private static MqttClient client;
private static final MqttConnectOptions options;

private static final MongoClient mongoClient;

public enum Type {
    Double, Boolean, String;
}
static {
    mongoClient = MongoConnection.getInstance();
    try {
        client = new MqttClient(BROKER_URI, CLIENT_ID);
    } catch (MqttException ex) {
        Logger.getLogger(MqttConnection.class.getName()).log(Level.SEVERE, null, ex);
    }
    options = new MqttConnectOptions();
    options.setUserName(USERNAME);
    options.setPassword(PASSWORD.toCharArray());
}

public static void connect() {
    try {
        if (Preferences.getProperty("mqttbroker-isAuth").equalsIgnoreCase("true")) {
            client.connect(options);
        } else {
            client.connect();
        }
        System.out.println(SDF.format(new Date()) + " - MQTT - Connecté au broker");
        client.setCallback(new ConnectionCallback());
        client.subscribe(TOPIC);
    } catch (MqttException ex) {
        System.out.println(SDF.format(new Date()) + " - MQTT - Erreur de connexion... Nouvelle tentative dans 5 secondes...");
        if (!client.isConnected()) {
            try {
                Thread.sleep(5000);
            } catch (InterruptedException ex1) {
                Logger.getLogger(MqttConnection.class.getName()).log(Level.SEVERE, null, ex1);
            }
            connect();
        }
    }
}

static class ConnectionCallback implements MqttCallback {

    @Override
    public void connectionLost(Throwable thrwbl) {
        System.out.println(SDF.format(new Date()) + " - MQTT - Perte de connexion... Tentative de reconnexion...");
        connect();
    }

    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        new Thread(new Runnable() {

            @Override
            public void run() {
                String[] tab = topic.split("/", 2);
                String dbName = tab[0];
                String collName = (tab.length > 1) ? tab[1] : tab[0];
                MongoDatabase db = mongoClient.getDatabase(dbName);
                MongoCollection collection = db.getCollection(collName);
                Document doc = (Document) collection.find().sort(Sorts.descending("date")).first();
                Object value = (doc != null) ? doc.get("value") : null;
                Type type = checkType(message.toString());
                switch (type) {
                    case Double :
                        if (doc == null || !((Double) value).equals(Double.valueOf(message.toString()))) {
                            collection.insertOne(new Document()
                                .append("date", SDF.format(new Date()))
                                .append("value", Double.valueOf(message.toString())));
                        }
                        break;
                    case Boolean :
                        if (doc == null || !((Boolean) value).equals(Boolean.valueOf(message.toString()))) {
                            collection.insertOne(new Document()
                                .append("date", SDF.format(new Date()))
                                .append("value", Boolean.valueOf(message.toString())));
                        }
                        break;
                    case String :
                        if (doc == null || !((String) value).equals(message.toString())) {
                            collection.insertOne(new Document()
                                .append("date", SDF.format(new Date()))
                                .append("value", message.toString()));
                        }
                        break;
                }
            }

            private Type checkType(String str) {
                if (str.equalsIgnoreCase("true") || str.equalsIgnoreCase("false"))
                    return Type.Boolean;
                else {
                    try {
                        Double.valueOf(str);
                        return Type.Double;
                    } catch (NumberFormatException e) {
                        return Type.String;
                    }
                }
            }

        }).start();
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken imdt) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }

}

由于