给我一个MQTTjava服务端示例，并用中文注释

以下是一个基于Java的MQTT服务端示例，注释为中文。

import org.eclipse.paho.client.mqttv3.*;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;

public class Server {

public static void main(String[] args) {

// 定义MQTT相关参数
String broker = "tcp://127.0.0.1:1883"; // MQTT 服务器地址和端口号
String clientId = "JavaServer"; // MQTT 客户端ID
MemoryPersistence persistence = new MemoryPersistence();

try {
// 创建MQTT客户端
MqttClient mqttClient = new MqttClient(broker, clientId, persistence);

// 创建MQTT连接选项
MqttConnectOptions connOpts = new MqttConnectOptions();
connOpts.setCleanSession(true); // 设置为不保持会话
System.out.println("Connecting to broker: " + broker);
mqttClient.connect(connOpts); // 连接MQTT服务器
System.out.println("Connected");

// 定义MQTT主题
String topic = "test/topic";
int qos = 2; // 消息QoS级别，0表示最多一次，1表示至少一次，2表示只有一次

// 创建MQTT消息
String content = "Hello from Java Server";
MqttMessage message = new MqttMessage(content.getBytes());
message.setQos(qos);

// 发送MQTT消息
System.out.println("Publishing message: " + content);
mqttClient.publish(topic, message); // 发送MQTT消息至主题
System.out.println("Message published");

// 断开MQTT连接
mqttClient.disconnect();
System.out.println("Disconnected");
System.exit(0);
} catch(MqttException me) {
System.out.println("reason "+me.getReasonCode());
System.out.println("msg "+me.getMessage());
System.out.println("loc "+me.getLocalizedMessage());
System.out.println("cause "+me.getCause());
System.out.println("excep "+me);
me.printStackTrace();
}
}
}