单元 2: 将个人电脑连接至 EnOS 并采集数据¶

在 EnOS 应用门户上完成 PC 的设备建模和设备注册之后，你现在可以使用 EnOS Java SDK for MQTT 进行编程，配置开发环境、编写连接代码、采集 PC 数据并上送至云端。

有关使用 EnOS Java SDK for MQTT 的详细信息，参阅 GitHub 上的 Readme 文件。

步骤 1：配置开发环境¶

设置 Java 开发环境，并添加必要的依赖项 Java SE 8 和 Maven 3，用于支持 EnOS Java SDK for MQTT 和系统信息采集。

安装 Java SE 8（JDK 8），下载地址：https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html。
安装 Maven 3，下载地址：http://maven.apache.org/download.cgi。
安装开发环境，如 IntelliJ IDEA，下载地址：https://www.jetbrains.com/idea/download/。

在已创建项目的 pom.xml 中，添加 EnOS Java SDK for MQTT 的依赖项：

<dependency>
    <groupId>com.enos-iot</groupId>
    <artifactId>enos-mqtt</artifactId>
    <version>2.5.2</version>
</dependency>

在项目的主 pom.xml 文件中，如下所示添加 oshi 依赖项，用于采集计算机操作系统和硬件信息：

<dependency>
    <groupId>com.github.oshi</groupId>
    <artifactId>oshi-core</artifactId>
    <version>3.13.2</version>
</dependency>

步骤 2：编写设备连接代码¶

通过 EnOS Java SDK for MQTT 编写代码，将 PC 连接到 EnOS 云端。

创建一个新的 Java 类（例如 Sample.java），并添加以下必要的 import 语句：

import com.enosiot.enos.iot_mqtt_sdk.core.ConnCallback;
import com.enosiot.enos.iot_mqtt_sdk.core.MqttClient;
import com.enosiot.enos.iot_mqtt_sdk.message.upstream.tsl.*;
import oshi.SystemInfo;
import oshi.hardware.HardwareAbstractionLayer;
import oshi.software.os.OperatingSystem;
import java.util.HashMap;
import java.util.Map;

声明将在程序中使用的变量，替换以下占位符：
```
private static final String uri = "tcp://{address}:11883"; // {address} 替换为实际 MQTT Broker 地址
private static final String productKey = "your_product_key";
private static final String deviceKey = "your_device_key";
private static final String deviceSecret = "your_device_secret";
private static MqttClient client;
```
替换说明：
- 将 {address} 和 {port} 替换为 EnOS 的 MQTT Broker 地址和端口。登录 EnOS 应用门户的开发控制台，点击右上角 帮助 > 环境信息 获取 MQTT Broker 地址和端口。
- 推荐在测试或教学场景中使用 TCP 端口 11883，无需额外配置，但安全性较低。如果需要使用安全性更高的 SSL TCP 端口（18883），请确保你所在的 EnOS 环境启用了 SSL，并配置客户端的 SSL 证书，如有需要可联系系统管理员。
- productKey，deviceKey 和 deviceSecret 是在单元 1 中注册 PC 时生成的设备三元组。

编写 connect() 函数以初始化设备连接，并确保连接成功后再继续执行：

public static void connect() throws Exception {
    System.out.println("Starting connection to EnOS Cloud...");
    try {
        client = new MqttClient(uri, productKey, deviceKey, deviceSecret);
        client.getProfile().setConnectionTimeout(60).setAutoReconnect(true);
        client.connect(new ConnCallback() {
            @Override
            public void connectComplete(boolean reconnect) {
                System.out.println("Connection successful" + (reconnect ? " (reconnected)" : ""));
            }

            @Override
            public void connectLost(Throwable cause) {
                System.out.println("Connection lost: " + cause.getMessage());
            }

            @Override
            public void connectFailed(Throwable cause) {
                System.out.println("Connection failed: " + cause.getMessage());
            }
        });
        // 等待连接成功，最多等待 5 秒
        int maxWaitTime = 5000; // 毫秒
        long startTime = System.currentTimeMillis();
        while (!client.isConnected() && (System.currentTimeMillis() - startTime) < maxWaitTime) {
            Thread.sleep(100);
        }
        if (!client.isConnected()) {
            throw new Exception("Failed to connect to EnOS Cloud within timeout period.");
        }
        System.out.println("Connection status: " + client.isConnected());
    } catch (Throwable e) {
        System.err.println("Connection error: " + e.getMessage());
        throw e;
    }
}

步骤 3：采集数据并将数据上传到 EnOS 云端¶

采集 PC 的系统和硬件数据，并将数据作为属性和测点上传到 EnOS 云端：

编写 collectDeviceInfo() 函数采集 PC 的系统和硬件数据。参考以下代码示例：

public static Map<String, Object> collectDeviceInfo() {
     SystemInfo si = new SystemInfo();
     HardwareAbstractionLayer hal = si.getHardware();
     OperatingSystem os = si.getOperatingSystem();

     Map<String, Object> data = new HashMap<>();
     data.put("system", os.toString());
     data.put("model", hal.getComputerSystem().getManufacturer() + " " + hal.getComputerSystem().getModel());
     data.put("cpu_core", hal.getProcessor().getLogicalProcessorCount());
     data.put("cpu_used", hal.getProcessor().getSystemCpuLoad());
     data.put("mem_total", hal.getMemory().getTotal());
     data.put("mem_used", hal.getMemory().getAvailable()); // 注意：mem_used 表示可用内存
     data.put("cpu_used_average", hal.getProcessor().getSystemLoadAverage());
     data.put("cpu_temperature", hal.getSensors().getCpuTemperature());

     return data;
 }

编写 updateAttribute() 函数，使用已采集的系统和硬件数据更新 EnOS 应用门户上 PC 设备的属性。参考以下代码示例：

public static void updateAttribute() {
     Map<String, Object> deviceInfo = collectDeviceInfo();
     System.out.println("Computer info: " + deviceInfo);
     AttributeUpdateRequest request = AttributeUpdateRequest.builder()
             .setQos(1)
             .addAttribute("system", deviceInfo.get("system"))
             .addAttribute("model", deviceInfo.get("model"))
             .addAttribute("cpu_core", deviceInfo.get("cpu_core"))
             .addAttribute("mem_total", deviceInfo.get("mem_total"))
             .build();
     System.out.println(">>> Update Attribute: " + request);

     try {
         AttributeUpdateResponse resp = client.publish(request);
         System.out.println("<-- Response: " + resp);
     } catch (Exception e) {
         System.err.println("Failed to update attributes: " + e.getMessage());
         e.printStackTrace();
     }
 }

编写 postMeasurepoint 函数，将采集的 CPU 负载和内存使用数据作为测点上传到 EnOS 云端。参考以下代码示例：

public static void postMeasurepoint(Map<String, Object> systemInfo) {
     MeasurepointPostRequest request = MeasurepointPostRequest.builder()
             .setQos(0)
             .addMeasurePoint("cpu_used", (Double) systemInfo.get("cpu_used"))
             .addMeasurePoint("mem_used", ((Long) systemInfo.get("mem_used")).doubleValue()) // 转换为 double 类型
             .build();
     System.out.println(">>> Post Measurepoint: " + request);

     try {
         MeasurepointPostResponse resp = client.publish(request);
         System.out.println("<-- Response: " + resp);
     } catch (Exception e) {
         System.err.println("Failed to post measurepoint: " + e.getMessage());
         e.printStackTrace();
     }
 }

步骤 4：运行程序并检查结果¶

编译并运行程序，验证设备连接和数据上传是否成功，并在 EnOS 应用门户上检查结果：

整合所有代码，创建一个完整的 Sample.java 文件：

import com.enosiot.enos.iot_mqtt_sdk.core.ConnCallback;
import com.enosiot.enos.iot_mqtt_sdk.core.MqttClient;
import com.enosiot.enos.iot_mqtt_sdk.message.upstream.tsl.*;
import oshi.SystemInfo;
import oshi.hardware.HardwareAbstractionLayer;
import oshi.software.os.OperatingSystem;
import java.util.HashMap;
import java.util.Map;

public class Sample {
    private static final String uri = "tcp://{address}:11883"; // 替换为实际 MQTT Broker 地址
    private static final String productKey = "your_product_key";
    private static final String deviceKey = "your_device_key";
    private static final String deviceSecret = "your_device_secret";
    private static MqttClient client;

    public static void main(String[] args) throws Exception {
        connect();
        updateAttribute();
        postMeasurepoint(collectDeviceInfo());
    }

    public static void connect() throws Exception {
        System.out.println("Starting connection to EnOS Cloud...");
        try {
            client = new MqttClient(uri, productKey, deviceKey, deviceSecret);
            client.getProfile().setConnectionTimeout(60).setAutoReconnect(true);
            client.connect(new ConnCallback() {
                @Override
                public void connectComplete(boolean reconnect) {
                    System.out.println("Connection successful" + (reconnect ? " (reconnected)" : ""));
                }

                @Override
                public void connectLost(Throwable cause) {
                    System.out.println("Connection lost: " + cause.getMessage());
                }

                @Override
                public void connectFailed(Throwable cause) {
                    System.out.println("Connection failed: " + cause.getMessage());
                }
            });
            // 等待连接成功，最多等待 5 秒
            int maxWaitTime = 5000; // 毫秒
            long startTime = System.currentTimeMillis();
            while (!client.isConnected() && (System.currentTimeMillis() - startTime) < maxWaitTime) {
                Thread.sleep(100);
            }
            if (!client.isConnected()) {
                throw new Exception("Failed to connect to EnOS Cloud within timeout period.");
            }
            System.out.println("Connection status: " + client.isConnected());
        } catch (Throwable e) {
            System.err.println("Connection error: " + e.getMessage());
            throw e;
        }
    }

    public static Map<String, Object> collectDeviceInfo() {
        SystemInfo si = new SystemInfo();
        HardwareAbstractionLayer hal = si.getHardware();
        OperatingSystem os = si.getOperatingSystem();

        Map<String, Object> data = new HashMap<>();
        data.put("system", os.toString());
        data.put("model", hal.getComputerSystem().getManufacturer() + " " + hal.getComputerSystem().getModel());
        data.put("cpu_core", hal.getProcessor().getLogicalProcessorCount());
        data.put("cpu_used", hal.getProcessor().getSystemCpuLoad());
        data.put("mem_total", hal.getMemory().getTotal());
        data.put("mem_used", hal.getMemory().getAvailable()); // 表示可用内存
        data.put("cpu_used_average", hal.getProcessor().getSystemLoadAverage());
        data.put("cpu_temperature", hal.getSensors().getCpuTemperature());

        return data;
    }

    public static void updateAttribute() {
        Map<String, Object> deviceInfo = collectDeviceInfo();
        System.out.println("Computer info: " + deviceInfo);
        AttributeUpdateRequest request = AttributeUpdateRequest.builder()
                .setQos(1)
                .addAttribute("system", deviceInfo.get("system"))
                .addAttribute("model", deviceInfo.get("model"))
                .addAttribute("cpu_core", deviceInfo.get("cpu_core"))
                .addAttribute("mem_total", deviceInfo.get("mem_total"))
                .build();
        System.out.println(">>> Update Attribute: " + request);

        try {
            AttributeUpdateResponse resp = client.publish(request);
            System.out.println("<-- Response: " + resp);
        } catch (Exception e) {
            System.err.println("Failed to update attributes: " + e.getMessage());
            e.printStackTrace();
        }
    }

    public static void postMeasurepoint(Map<String, Object> systemInfo) {
        MeasurepointPostRequest request = MeasurepointPostRequest.builder()
                .setQos(0)
                .addMeasurePoint("cpu_used", (Double) systemInfo.get("cpu_used"))
                .addMeasurePoint("mem_used", ((Long) systemInfo.get("mem_used")).doubleValue())
                .build();
        System.out.println(">>> Post Measurepoint: " + request);

        try {
            MeasurepointPostResponse resp = client.publish(request);
            System.out.println("<-- Response: " + resp);
        } catch (Exception e) {
            System.err.println("Failed to post measurepoint: " + e.getMessage());
            e.printStackTrace();
        }
    }
}

编译并运行程序。如果连接和数据上传成功，程序将输出类似以下结果：

Start connect with callback ...

connect result :true
connect success

Computer info: {mem_used=1401421824, cpu_used_average=-1.0, cpu_temperature=0.0, cpu_used=1.0, system=Microsoft Windows 10 build 17134, cpu_core=4, model=LENOVO 80T9, mem_total=8135401472}

>>> Update Attribute: AnswerableMessageBody{id='null', method='thing.attribute.update', version='null', params={attributes={system=Microsoft Windows 10 build 17134, cpu_core=4, model=LENOVO 80T9, mem_total=8135401472}}}

>>>Post Measurepoint: AnswerableMessageBody{id='null', method='thing.measurepoint.post', version='null', params={measurepoints={mem_used=1314672640, cpu_used=0.4697233989534014}, time=1565841030584}}

登录 EnOS 应用门户的开发者控制台，在 设备管理 > 设备资产 中检查 PC 设备的状态变更。设备的状态为在线。
在设备详情页面的属性选项卡下，检查 PC 设备的属性是否更新成功。
在设备详情页面上测点选项卡下，检查上传的 cpu_used 和 mem_used 测点数据是否正确展示。

注意：如果 mem_used 数据未显示，请确保 EnOS 设备模型中 mem_used 测点的数据类型定义为 double。若仍有问题，检查 postMeasurepoint 函数中的数据类型转换。

下一单元¶

单元 3：监测 CPU 负载