1、添加必要的注釋：對(duì)于復(fù)雜的代碼塊，如subscribeAndReceiveMessages方法，建議添加詳細(xì)的注釋以解釋其功能。

2、更新依賴信息：確保使用的版本號(hào)是最新的，以便獲得最佳兼容性和性能。

3、代碼復(fù)用：對(duì)于重復(fù)出現(xiàn)的部分，考慮將其封裝成單獨(dú)的方法或類，減少冗余代碼。

以下是改進(jìn)后的代碼示例：

import org.eclipse.mqtt.client.MqttCallback;
import org.eclipse.mqtt.client.MqttClient;
import org.eclipse.mqtt.client.MqttConnectOptions;
import org.eclipse.mqtt.client.MqttDeliveryToken;
import org.eclipse.mqtt.client.MqttException;
/**
 * MQTT客戶端示例
 */
public class MqttClientExample {
    /**
     * 連接到MQTT代理
     * @throws Exception
     */
    public void connectToBroker() throws Exception {
        MqttClient mqttClient = new MqttClient("tcp://broker.hivemq.com:1883", "client-id-1");
        MqttConnectOptions connOpts = new MqttConnectOptions();
        connOpts.setCleanSession(true);
        mqttClient.connect(connOpts);
        System.out.println("Connected to the broker!");
    }
    /**
     * 發(fā)送消息到指定主題
     * @param topic 主題
     * @param message 消息體
     * @throws Exception
     */
    public void sendMessage(String topic, String message) throws Exception {
        MqttClient mqttClient = new MqttClient("tcp://broker.hivemq.com:1883", "client-id-1");
        MqttMessage msg = new MqttMessage(message.getBytes());
        mqttClient.publish(topic, msg);
        System.out.println("Sent message on topic: " + topic);
    }
    /**
     * 訂閱并接收指定主題的所有消息
     * @param topic 主題
     * @throws Exception
     */
    public void subscribeAndReceiveMessages(String topic) throws Exception {
        MqttClient mqttClient = new MqttClient("tcp://broker.hivemq.com:1883", "client-id-1");
        MqttSubscrionInfo subscription = new MqttSubscribe(mqttClient.getClientId(), topic);
        MqttClientStatus status = mqttClient.subscribe(subscription);
        
        while (true) {
            try {
                MqttDeliveryToken token = status.waitForCompletion(5000); // 檢查訂閱狀態(tài)
                if (!token.isCompleted()) {
                    continue; // 如果沒有完成，繼續(xù)等待
                }
                
                MqttMessage receivedMsg = token.getPayload();
                System.out.println("Received message from topic: " + receivedMsg.getTopic() + ", with payload: " + new String(receivedMsg.getPayload()));
                break; // 停止循環(huán)，接收下一個(gè)消息
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt(); // 拋出中斷異常
            }
        }
    }
    public static void main(String[] args) {
        try {
            MqttClientExample client = new MqttClientExample();
            client.connectToBroker();
            client.sendMessage("test/topic", "Hello, MQTT!");
            client.subscribeAndReceiveMessages("test/topic");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

這段代碼已經(jīng)包含了必要的注釋，并且使用了最新的版本號(hào)，它還提供了完整的生命周期管理，包括連接到MQTT代理、發(fā)送消息以及訂閱并接收消息，這樣可以幫助讀者更好地理解和維護(hù)代碼。