在物联网应用程序中使用java框架构建移动应用程序

// Spring Boot 服务类
@SpringBootApplication
public class IotMobileApplication {

    public static void main(String[] args) {
        SpringApplication.run(IotMobileApplication.class, args);
    }
}

// MQTT 通信类
public class MqttClient {

    private MqttClient client;

    // 与 MQTT 代理建立连接
    public void connect() {
        // 省略连接逻辑
    }

    // 发送消息到 MQTT 代理
    public void publish(String topic, String message) {
        // 省略发布逻辑
    }
}

// Android 应用程序类
public class MainActivity extends AppCompatActivity {

    private MqttClient mqttClient;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 初始化 MQTT 客户端
        mqttClient = new MqttClient();
        mqttClient.connect();
    }

    // 响应按钮点击事件，发送消息控制设备
    public void onButtonClick(View view) {
        // 发送控制消息，如打开或关闭设备
        mqttClient.publish("device/lightbulb", "on");
    }
}

// Spring Boot 服务类
// ....

// MQTT 通信类
// ....

// Android 应用程序类
public class MainActivity extends AppCompatActivity {

    private MqttClient mqttClient;
    private LineChart temperatureChart;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 初始化 MQTT 客户端和温度图表
        mqttClient = new MqttClient();
        mqttClient.connect();
        temperatureChart = (LineChart) findViewById(R.id.temperature_chart);

        // 订阅温度主题并处理收到的消息
        mqttClient.subscribe("device/temperature");
        mqttClient.setOnMessageReceivedListener(new MqttCallback() {
            @Override
            public void messageArrived(String topic, MqttMessage message) {
                // 将接收到的温度数据添加到图表中
                float temperature = Float.parseFloat(message.toString());
                temperatureChart.addDataPoint(temperature);
            }
        });
    }
}