单元 3: 将个人电脑连接至EnOS并采集数据¶

在EnOS 管理控制台上完成PC的设备建模、设备注册和数据存储策略配置之后，您现在可以使用EnOS Java SDK for MQTT进行编程，以将PC连接到EnOS并开始采集数据。

有关用于MQTT的EnOS Java SDK的详细信息，请参阅以下网站上的自述文件。 GitHub.

步骤 1: 搭建开发环境¶

EnOS Java SDK for MQTT要求安装Java SE 8 and Maven 3。按照以下步骤设置开发环境：

安装JDK，下载地址：https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html.
安装Maven，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/。

在你的创建的project的pom.xml中，添加EnOS Java SDK for MQTT的依赖如下：

<dependency>
    <groupId>com.envisioniot</groupId>
    <artifactId>enos-mqtt</artifactId>
    <version>2.1.2</version>
</dependency>

在你开发项目的主pom.xml文件中，将oshi（用于摄取计算机操作系统和硬件信息的开源插件）添加为依赖项，如下所示：
```
<dependency>
    <groupId>com.github.oshi</groupId>
    <artifactId>oshi-core</artifactId>
    <version>3.13.2</version>
</dependency>
```

步骤 2. 设备连接编程¶

设置开发环境后，请执行以下步骤将PC连接到EnOS Cloud：

声明将在程序中使用的变量，请参见以下示例：
```
private static final String uri = "tcp://{host}:{port}";
private static final String productKey = "product_key";
private static final String deviceKey = "device_key";
private static final String deviceSecret = "device_secret";
private static MqttClient client;
```
- 服务器的host和port随云区域和实例的不同而不同。对于私有云实例，请联系您的Envision项目经理或支持代表以获取主机和端口信息。
- productKey，deviceKey和deviceSecret是在单元 1中注册PC时生成的设备属性。

声明主要函数connect（）初始化设备连接。请参见以下示例：

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

使用“连接”功能将PC连接到EnOS Cloud。请参见以下代码段：

public static void connect() {
    System.out.println("Start connect with callback ... ");
    try {
        client = new MqttClient(uri, productKey, deviceKey, deviceSecret); // json device
        client.getProfile().setConnectionTimeout(60).setAutoReconnect(true);
        client.connect(new IConnectCallback() {
            @Override
            public void onConnectSuccess() {
                System.out.println("connect success");
            }

            @Override
            public void onConnectLost() {
                System.out.println("onConnectLost");
            }

            @Override
            public void onConnectFailed(int reasonCode) {
                System.out.println("onConnectFailed : " + reasonCode);
            }

        });
    } catch (EnvisionException e) {
        e.printStackTrace();
    }
    System.out.println("connect result :" + client.isConnected());
}

步骤 3. 编程以采集数据并将数据上传到EnOS Cloud¶

将PC连接到EnOS后，请按照以下步骤提取PC的系统和硬件数据，并将数据上传到EnOS Cloud：

使用collectDeviceInfo（）函数提取PC的系统和硬件数据。请参见以下代码段：

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

    Map<String, Object> data=new HashMap<String, Object>();
    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());
    data.put("cpu_used_average", hal.getProcessor().getSystemLoadAverage());
    data.put("cpu_temperature", hal.getSensors().getCpuTemperature());

    return data;
}

使用“ updateAttribute（）”函数使用已摄取的系统和硬件数据更新EnOS 管理控制台上PC设备的属性。请参见以下代码段：

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("<-- " + resp);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

使用postMeasurepoint函数将摄取的CPU负载和内存使用情况数据上传到EnOS Cloud。请参见以下代码段：

public static void postMeasurepoint(Map<String, Object> systemInfo) {
    MeasurepointPostRequest request = MeasurepointPostRequest.builder()
            .setQos(0)
            .addMeasurePoint("cpu_used", Double.parseDouble(systemInfo.get("cpu_used").toString())+0.0)
            .addMeasurePoint("mem_used", systemInfo.get("mem_used"))
            .build();
    System.out.println(">>> Post Measurepoint: "+request);

    try {
        MeasurepointPostResponse resp = client.publish(request);
        System.out.println("<-- " + resp);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

步骤 4. 运行程序并检查结果¶

编译并运行程序以进行设备连接和数据提取。请参见以下程序代码示例：

import java.util.HashMap;
import java.util.Map;

import com.envisioniot.enos.iot_mqtt_sdk.core.IConnectCallback;
import com.envisioniot.enos.iot_mqtt_sdk.core.MqttClient;
import com.envisioniot.enos.iot_mqtt_sdk.core.exception.EnvisionException;
import com.envisioniot.enos.iot_mqtt_sdk.message.upstream.tsl.*;
import oshi.hardware.HardwareAbstractionLayer;
import oshi.software.os.OperatingSystem;

public class Sample {

    private static final String uri = "tcp://{host}:{port}";
    private static final String productKey = "product_key";
    private static final String deviceKey = "device_key";
    private static final String deviceSecret = "device_secret";

    private static MqttClient client;

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

    }

    // Device connection initialization
    public static void connect() {
        System.out.println("start connect with callback ... ");
        try {
            client = new MqttClient(uri, productKey, deviceKey, deviceSecret);
            client.getProfile().setConnectionTimeout(60).setAutoReconnect(true);
            client.connect(new IConnectCallback() {
                @Override
                public void onConnectSuccess() {
                    System.out.println("connect success");
                }

                @Override
                public void onConnectLost() {
                    System.out.println("onConnectLost");
                }

                @Override
                public void onConnectFailed(int reasonCode) {
                    System.out.println("onConnectFailed : " + reasonCode);
                }

            });
        } catch (EnvisionException e) {
            e.printStackTrace();
        }
        System.out.println("connect result :" + client.isConnected());
    }

    // Ingesting PC system and hardware data
    public static Map<String, Object> collectDeviceInfo() {
        oshi.SystemInfo si = new oshi.SystemInfo();
        HardwareAbstractionLayer hal = si.getHardware();
        OperatingSystem os = si.getOperatingSystem();

        Map<String, Object> data = new HashMap<String, Object>();
        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());
        data.put("cpu_used_average", hal.getProcessor().getSystemLoadAverage());
        data.put("cpu_temperature", hal.getSensors().getCpuTemperature());

        return data;
    }

    // Updating PC attributes with the ingested system and hardware 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("<-- " + resp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // Uploading PC system data into EnOS Cloud
    public static void postMeasurepoint(Map<String, Object> systemInfo) {
        MeasurepointPostRequest request = MeasurepointPostRequest.builder()
                .setQos(0)
                .addMeasurePoint("cpu_used", Double.parseDouble(systemInfo.get("cpu_used").toString())+0.0)
                .addMeasurePoint("mem_used", systemInfo.get("mem_used"))
                .build();
        System.out.println(">>> Post Measurepoint: "+request);

        try {
            MeasurepointPostResponse resp = client.publish(request);
            System.out.println("<-- " + resp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

检查程序的运行结果。如果设备连接成功，程序将返回以下示例结果：

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}}

在EnOS 管理控制台上的 设备列表 中检查PC设备的状态更改。设备的状态将从 未激活 更改为在线。
在 设备详情 页面的属性选项卡下，检查已更新的PC设备的属性。
检查 设备详情 页面上测点选项卡下发布到云的cpu_used和mem_used测点的数据。

下一单元¶

监测CPU负载