我试图实现虚假代理（实际上它是mqtt用户回调中的mqtt发布者客户端）。有3个独立的发布者客户端，它们发布0到1之间的随机数。这个虚假经纪人只是总结这个随机数，然后发布到另一个主题。 （也许不是以正确的方式，但现在没关系）这个解决方案正在运行但是在一些传入的消息之后，这个代理停止工作。我试图调试它，但我发现只有ClassNotFound Exceptions ...这是我的FakeBroker和它的Callback实现。
public class FakeBroker implements Runnable{
public static final String BROKER_URL = "";
public static final String TOPIC_FAKE_A = "";
public static final String TOPIC_FAKE_B = "";
public static final String TOPIC_FAKE_C = "";
public static final String USER_NAME = "";
public static final char[] USER_PSW = "".toCharArray();
private MqttClient client;
private MqttConnectOptions options;
private SubscriberCallback callback;
public FakeBroker() {
options = new MqttConnectOptions();
options.setUserName(USER_NAME);
options.setPassword(USER_PSW);
options.setCleanSession(false);
callback = new SubscriberCallback();
try {
client = new MqttClient(BROKER_URL, MqttClient.generateClientId()+"-sub");
client.setCallback(callback);
} catch (MqttException e) {
e.printStackTrace();
System.exit(1);
}
}
public void start() {
try {
client.connect(options);
System.out.println("Fake Broker are connected to the cloud.");
client.subscribe(TOPIC_FAKE_A);
client.subscribe(TOPIC_FAKE_B);
client.subscribe(TOPIC_FAKE_C);
} catch (MqttException e) {
e.printStackTrace();
}
}
@Override
public void run() {
start();
}
}
这就是它的回调
public class SubscriberCallback implements MqttCallback {
public static final String BROKER_URL = "";
public static final String TOPIC_FAKE_BROKER = "";
public static final String USER_NAME = "";
public static final char[] USER_PSW = "".toCharArray();
private MqttClient client;
private MqttConnectOptions options;
private int counter = 1;
private int result = 0;
public SubscriberCallback() {
try {
client = new MqttClient(BROKER_URL, "4-pub");
options = new MqttConnectOptions();
options.setPassword(USER_PSW);
options.setUserName(USER_NAME);
} catch (MqttException e) {
e.printStackTrace();
}
}
@Override
public void connectionLost(Throwable throwable) {
}
@Override
public void messageArrived(String topic, MqttMessage mqttMessage) throws Exception {
System.out.println("Message Arrived. Topic " + topic + " message: " +mqttMessage + " ---- Message Counter: " + counter);
int number = Integer.parseInt(mqttMessage.toString());
result += number;
if (counter%3 == 0) {
publishAway(new MqttMessage(Integer.toString(result).getBytes()));
result = 0;
}
incrementCounter();
}
private void publishAway(MqttMessage mqttMessage) throws MqttException {
client.connect(options);
final MqttTopic topicFakeBroker = client.getTopic(TOPIC_FAKE_BROKER);
topicFakeBroker.publish(mqttMessage);
client.disconnect();
System.out.println("Fake broker got the message " + mqttMessage + " and published away to" + topicFakeBroker.getName());
}
@Override
public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {
}
private void incrementCounter() {
counter++;
}
}
当然我使用有效的BROKER_URL和TOPICS但这些信息是保密的。谢谢你的回答！ ：）