阿里云物联网平台NET SDK实现RRPC服务端调用

概述

MQTT协议是基于PUB/SUB的异步通信模式，不适用于服务端同步控制设备端返回结果的场景。前面博客基于开源Java MQTT Client的阿里云物联网平台RRPC功能测试介绍了RRPC原理，使用Open API实现服务端的调用实现。本文介绍如何使用NET SDK在本地实现RRPC的服务端调用。

Step By Step

1、创建产品与设备

参考链接 准备工作部分。

2、设备端Code

import com.alibaba.taro.AliyunIoTSignUtil;
import org.eclipse.paho.client.mqttv3.*;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import java.util.HashMap;
import java.util.Map;

public class IoTRRPCForSysTopicDemo {

<span class="hljs-comment">// 设备三元组信息</span>
public <span class="hljs-keyword">static</span> <span class="hljs-built_in">String</span> productKey = <span class="hljs-string">"a16MX******"</span>;
public <span class="hljs-keyword">static</span> <span class="hljs-built_in">String</span> deviceName = <span class="hljs-string">"RRPC******"</span>;
public <span class="hljs-keyword">static</span> <span class="hljs-built_in">String</span> deviceSecret = <span class="hljs-string">"Ayq069ifWO7WOmwKyswNLv6E********"</span>;
public <span class="hljs-keyword">static</span> <span class="hljs-built_in">String</span> regionId = <span class="hljs-string">"cn-shanghai"</span>;

<span class="hljs-comment">// RRPC 系统Topic</span>
private <span class="hljs-keyword">static</span> <span class="hljs-built_in">String</span> subTopic = <span class="hljs-string">"/sys/"</span> + productKey + <span class="hljs-string">"/"</span> + deviceName+ <span class="hljs-string">"/rrpc/request/+"</span>;
private <span class="hljs-keyword">static</span> MqttClient mqttClient;

public <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> main(<span class="hljs-built_in">String</span> [] args) {

    initAliyunIoTClient();

    <span class="hljs-comment">// RRPC订阅Topic</span>
    <span class="hljs-keyword">try</span> {
        mqttClient.subscribe(subTopic);
    } <span class="hljs-keyword">catch</span> (MqttException e) {
        e.printStackTrace();
    }

    mqttClient.setCallback(<span class="hljs-keyword">new</span> MqttCallback() {
        @Override
        public <span class="hljs-keyword">void</span> connectionLost(Throwable cause) {
            System.out.println(<span class="hljs-string">"connectionLost:"</span> + cause.getMessage());
        }

        @Override
        public <span class="hljs-keyword">void</span> messageArrived(<span class="hljs-built_in">String</span> topic, MqttMessage message) throws Exception {
            System.out.println(<span class="hljs-string">"message: "</span> + <span class="hljs-keyword">new</span> <span class="hljs-built_in">String</span>(message.getPayload()));
            System.out.println(<span class="hljs-string">"topic:"</span> + topic);

            <span class="hljs-comment">// 根据RRPC请求消息Topic，构建RRPC响应消息Topic</span>
            <span class="hljs-built_in">String</span> responseTopic = topic.replace(<span class="hljs-string">"request"</span>,<span class="hljs-string">"response"</span>);
            MqttMessage message1 = <span class="hljs-keyword">new</span> MqttMessage(<span class="hljs-string">"resonse demo"</span>.getBytes(<span class="hljs-string">"utf-8"</span>));
            mqttClient.publish(responseTopic, message1);
        }

        @Override
        public <span class="hljs-keyword">void</span> deliveryComplete(IMqttDeliveryToken token) {
        }
    });
}

<span class="hljs-comment">/***
 * 初始化Client
 */</span>
private <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> initAliyunIoTClient() {

    <span class="hljs-keyword">try</span> {
        <span class="hljs-built_in">String</span> clientId = <span class="hljs-string">"java"</span> + System.currentTimeMillis();

        <span class="hljs-built_in">Map</span>&lt;<span class="hljs-built_in">String</span>, <span class="hljs-built_in">String</span>&gt; params = <span class="hljs-keyword">new</span> HashMap&lt;&gt;(<span class="hljs-number">16</span>);
        params.put(<span class="hljs-string">"productKey"</span>, productKey);
        params.put(<span class="hljs-string">"deviceName"</span>, deviceName);
        params.put(<span class="hljs-string">"clientId"</span>, clientId);
        <span class="hljs-built_in">String</span> timestamp = <span class="hljs-built_in">String</span>.valueOf(System.currentTimeMillis());
        params.put(<span class="hljs-string">"timestamp"</span>, timestamp);

        <span class="hljs-comment">// cn-shanghai</span>
        <span class="hljs-built_in">String</span> targetServer = <span class="hljs-string">"tcp://"</span> + productKey + <span class="hljs-string">".iot-as-mqtt."</span> + regionId + <span class="hljs-string">".aliyuncs.com:1883"</span>;

        <span class="hljs-built_in">String</span> mqttclientId = clientId + <span class="hljs-string">"|securemode=3,signmethod=hmacsha1,timestamp="</span> + timestamp + <span class="hljs-string">"|"</span>;
        <span class="hljs-built_in">String</span> mqttUsername = deviceName + <span class="hljs-string">"&amp;"</span> + productKey;
        <span class="hljs-built_in">String</span> mqttPassword = AliyunIoTSignUtil.sign(params, deviceSecret, <span class="hljs-string">"hmacsha1"</span>);

        connectMqtt(targetServer, mqttclientId, mqttUsername, mqttPassword);

    } <span class="hljs-keyword">catch</span> (Exception e) {
        System.out.println(<span class="hljs-string">"initAliyunIoTClient error "</span> + e.getMessage());
    }
}

public <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> connectMqtt(<span class="hljs-built_in">String</span> url, <span class="hljs-built_in">String</span> clientId, <span class="hljs-built_in">String</span> mqttUsername, <span class="hljs-built_in">String</span> mqttPassword) throws Exception {

    MemoryPersistence persistence = <span class="hljs-keyword">new</span> MemoryPersistence();
    mqttClient = <span class="hljs-keyword">new</span> MqttClient(url, clientId, persistence);
    MqttConnectOptions connOpts = <span class="hljs-keyword">new</span> MqttConnectOptions();
    <span class="hljs-comment">// MQTT 3.1.1</span>
    connOpts.setMqttVersion(<span class="hljs-number">4</span>);
    connOpts.setAutomaticReconnect(<span class="hljs-literal">false</span>);
    connOpts.setCleanSession(<span class="hljs-literal">true</span>);

    connOpts.setUserName(mqttUsername);
    connOpts.setPassword(mqttPassword.toCharArray());
    connOpts.setKeepAliveInterval(<span class="hljs-number">60</span>);

    mqttClient.connect(connOpts);
}

}

3、云端Code

• 3.1 SDK安装:

Install-Package aliyun-net-sdk-iot -Version 7.4.0

• 3.2 NET Code

using System;
using System.Text;
using Aliyun.Acs.Core;
using Aliyun.Acs.Core.Exceptions;
using Aliyun.Acs.Core.Profile;
using Aliyun.Acs.Iot.Model.V20180120;

namespace IoTRRPCDemo
{

<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Program</span>
</span>{
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> Main(string[] args)
    {
        <span class="hljs-comment">// ak,sk https://yq.aliyun.com/articles/693979</span>
        IClientProfile profile = DefaultProfile.GetProfile(<span class="hljs-string">"cn-shanghai"</span>, <span class="hljs-string">"LTAIOZZg********"</span>, <span class="hljs-string">"v7CjUJCMk7j9aKduMAQLjy********"</span>);
        DefaultAcsClient client = <span class="hljs-keyword">new</span> DefaultAcsClient(profile);
        client.SetConnectTimeoutInMilliSeconds(<span class="hljs-number">8000</span>);<span class="hljs-comment">// 设置 Client 连接超时时间，默认是5S，RRPC响应超过5S是必须设置</span>

        <span class="hljs-keyword">var</span> request = <span class="hljs-keyword">new</span> RRpcRequest();
        request.Timeout = <span class="hljs-number">8000</span>;
        <span class="hljs-comment">// 设置设备三元组信息</span>
        request.DeviceName = <span class="hljs-string">"RRPC******"</span>;
        request.RequestBase64Byte = <span class="hljs-string">"5raI5oGv5LiL6KGM5rWL6K+V"</span>;  <span class="hljs-comment">// 消息下行测试 base64编码内容</span>
        request.ProductKey = <span class="hljs-string">"a16MX******"</span>;

        <span class="hljs-keyword">try</span>
        {
            <span class="hljs-keyword">var</span> response = client.GetAcsResponse(request);
            Console.WriteLine(Encoding.Default.GetString(response.HttpResponse.Content));
            Console.ReadKey();
        }
        <span class="hljs-keyword">catch</span> (ServerException e)
        {
            Console.WriteLine(<span class="hljs-string">"ServerException:"</span>);
            Console.WriteLine(e);
            Console.ReadKey();
        }
        <span class="hljs-keyword">catch</span> (ClientException e)
        {
            Console.WriteLine(<span class="hljs-string">"ClientException: "</span>);
            Console.WriteLine(e);
            Console.ReadKey();
        }
    }
}

}

4、测试情况

• 4.1 设备端

• 4.2 云端

参考链接

基于开源Java MQTT Client的阿里云物联网平台RRPC功能测试