mqtt.rar_mqtt_recognize9gx

package mqtt; import java.util.concurrent.ScheduledExecutorService; import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken; import org.eclipse.paho.client.mqttv3.MqttCallback; import org.eclipse.paho.client.mqttv3.MqttClient; import org.eclipse.paho.client.mqttv3.MqttConnectOptions; import org.eclipse.paho.client.mqttv3.MqttException; import org.eclipse.paho.client.mqttv3.MqttMessage; import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence; /** * 模拟一个客户端接收消息 * @author rao * */ public class ClientSearch { public static String str=""; public static final String HOST = "tcp://172.16.34.181:8848"; //服务器内置主题，用来监测当前服务器上连接的客户端数量（$SYS/broker/clients/connected） public static final String TOPIC1 = "$SYS/broker/clients/connected"; private static final String clientid = "client13"; private MqttClient client; private MqttConnectOptions options; private String userName = "admin"; private String passWord = "password"; @SuppressWarnings("unused") private ScheduledExecutorService scheduler; public void start() throws MqttException { // host为主机名，clientid即连接MQTT的客户端ID，一般以唯一标识符表示，MemoryPersistence设置clientid的保存形式，默认为以内存保存 client = new MqttClient(HOST, clientid, new MemoryPersistence()); // MQTT的连接设置 options = new MqttConnectOptions(); // 设置是否清空session,这里如果设置为false表示服务器会保留客户端的连接记录，设置为true表示每次连接到服务器都以新的身份连接 options.setCleanSession(false); // 设置连接的用户名 options.setUserName(userName); // 设置连接的密码 options.setPassword(passWord.toCharArray()); // 设置超时时间 单位为秒 options.setConnectionTimeout(10); // 设置会话心跳时间 单位为秒 服务器会每隔1.5*20秒的时间向客户端发送个消息判断客户端是否在线，但这个方法并没有重连的机制 options.setKeepAliveInterval(20); // 设置回调 client.setCallback(new MqttCallback(){ public void connectionLost(Throwable cause) { // 连接丢失后，一般在这里面进行重连 // System.out.println("连接断开，可以做重连"); } public void deliveryComplete(IMqttDeliveryToken token) { System.out.println("deliveryComplete---------" + token.isComplete()); } public void messageArrived(String topic, MqttMessage message) throws Exception { try { str = message.toString(); // System.out.println(" 从服务器收到的消息为:"+message.toString()); } catch (Exception e) { e.printStackTrace(); } } }); // MqttTopic topic = client.getTopic(TOPIC1); // setWill方法，如果项目中需要知道客户端是否掉线可以调用该方法。设置最终端口的通知消息 // options.setWill(topic, "close".getBytes(), 2, true); //遗嘱 client.connect(options); //订阅消息 int[] Qos = {1}; String[] topic1 = {TOPIC1}; client.subscribe(topic1, Qos); } @SuppressWarnings("static-access") //用来给调用处返回消息内容 public String resc() { return this.str; } }