使用Paho MqttClient在Android上尝试Mqtt连接

implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.2.5'

String serverUri = "tcp://mqtt.example.com:1883";
String clientId = "android-client";
MqttClient mqttClient = new MqttClient(serverUri, clientId);

mqttClient.setCallback(new MqttCallback() {
    @Override
    public void connectionLost(Throwable cause) {
        // 处理连接丢失事件
    }

    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        // 处理接收到的消息
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        // 处理消息发送完成事件
    }
});

MqttConnectOptions options = new MqttConnectOptions();
options.setUserName("username");
options.setPassword("password".toCharArray());
mqttClient.connect(options);

String topic = "my/topic";
int qos = 1;
mqttClient.subscribe(topic, qos);

String topic = "my/topic";
String payload = "Hello, MQTT!";
int qos = 1;
boolean retained = false;
mqttClient.publish(topic, payload.getBytes(), qos, retained);

mqttClient.disconnect();