内容简介：Willin: Azure Node.js IoT Hub开发指南
IOT Hub应用实际开发过程中的一些注意细节
资源:
- 创建设备: https://www.npmjs.com/package/azure-iothub
- IoT Hub(基于Event Hubs)消息管理: https://www.npmjs.com/package/azure-event-hubs
- 开发调试工具: https://www.npmjs.com/package/iothub-explorer
简单发送接收示例
1. 注册设备
const iothub = require('azure-iothub');
const registry = iothub.Registry.fromConnectionString('[connectionString]');
const device = new iothub.Device(null);
device.deviceId = '[deviceId]';
function printDeviceInfo(err, deviceInfo, res){
if (deviceInfo) {
console.log(JSON.stringify(deviceInfo, null, 2));
console.log(`Device id:${deviceInfo.deviceId}`);
console.log(`Device key:${deviceInfo.authentication.symmetricKey.primaryKey}`);
}
}
// 删除设备 registry.delete(deviceId, (err, deviceInfo, res) => {});
registry.create(device, (err, deviceInfo, res) => {
if (err) {
registry.get(device.deviceId, printDeviceInfo);
}
if (deviceInfo) {
printDeviceInfo(err, deviceInfo, res);
}
});
2. 模拟设备发送消息
const clientFromConnectionString = require('azure-iot-device-mqtt').clientFromConnectionString;
const Message = require('azure-iot-device').Message;
const connectionString = 'HostName=[修改连接主机];DeviceId=[deviceID];SharedAccessKey=[连接密钥]';
const client = clientFromConnectionString(connectionString);
function printResultFor(op){
return function printResult(err, res){
if (err) console.log(`${op}error:${err.toString()}`);
if (res) console.log(`${op}status:${res.constructor.name}`);
};
}
const connectCallback = function(err){
if (err) {
console.log(`Could not connect:${err}`);
} else {
console.log('Client connected');
// Create a message and send it to the IoT Hub every second
setInterval(()=> {
const windSpeed = 10 + (Math.random() * 4);
const data = JSON.stringify({ deviceId: 'myFirstNodeDevice', windSpeed });
const message = new Message(data);
console.log(`Sending message:${message.getData()}`);
client.sendEvent(message, printResultFor('send'));
}, 1000);
}
};
client.open(connectCallback);
3. 服务器端接收消息
const EventHubClient = require('azure-event-hubs').Client;
const connectionString = 'HostName=[修改连接主机];SharedAccessKeyName=iothubowner;SharedAccessKey=[修改连接密钥]';
const printError = function(err){
console.log(err.message);
};
const printMessage = function(message){
console.log('Message received: ');
console.log(JSON.stringify(message.body));
Object.getOwnPropertyNames(message).forEach((x) => {
console.log(x, message[x]);
});
console.log('');
};
const client = EventHubClient.fromConnectionString(connectionString);
client.open()
.then(client.getPartitionIds.bind(client))
.then(partitionIds=> partitionIds.map(partitionId=> client.createReceiver('$Default', partitionId, { startAfterTime: Date.now()}).then((receiver) => {
console.log(`Created partition receiver:${partitionId}`);
receiver.on('errorReceived', printError);
receiver.on('message', printMessage);
})))
.catch(printError);
注意:
- 客户端传的
properties,在消息体中是message.applicationProperties -
message包含的属性如下:
[ 'partitionKey', 'body', 'enqueuedTimeUtc', 'offset', 'properties', 'applicationProperties', 'sequenceNumber', 'annotations', 'systemProperties' ]
消息体示例:
Message received:
partitionKey undefined
body { deviceId: 'myFirstNodeDevice', windSpeed: 10.51685587945142 }
enqueuedTimeUtc 2017-06-13T01:21:02.519Z
offset 73240
properties undefined
applicationProperties { asdf: 'asdfz' }
sequenceNumber 182
annotations { 'x-opt-sequence-number': 182,
'x-opt-offset': '73240',
'x-opt-enqueued-time': 2017-06-13T01:21:02.519Z,
'iothub-connection-device-id': 'myFirstNodeDevice',
'iothub-connection-auth-method': '{ "scope": "device", "type": "sas", "issuer": "iothub" }',
'iothub-connection-auth-generation-id': 'xxxxxxx',
'iothub-enqueuedtime': 2017-06-13T01:21:02.786Z,
'iothub-message-source': 'Telemetry' }
systemProperties undefined
配置路由(需要Event Hubs)
1. 创建Event Hubs
2. 从事件中心创建实体
3. 获取连接字符串
点击进入已创建的实体
不要从别处获得连接字符串,因为可能无法连接. 最终获得的连接字符串应当包含 EntityPath 字段,类似:
Endpoint=sb://xxxx.servicebus.chinacloudapi.cn/;SharedAccessKeyName=iothubroutes_xxxx;SharedAccessKey=xxxx;EntityPath=xxxx
4. 创建Endpoint
将 Event Hubs 里的事件关联到 IoT Hub
5. 创建路由
示例代码
1. 修改刚才的发送示例
const clientFromConnectionString = require('azure-iot-device-mqtt').clientFromConnectionString;
const Message = require('azure-iot-device').Message;
const connectionString = 'HostName=[修改连接主机];DeviceId=[deviceID];SharedAccessKey=[连接密钥]';
const client = clientFromConnectionString(connectionString);
function printResultFor(op){
return function printResult(err, res){
if (err) console.log(`${op}error:${err.toString()}`);
if (res) console.log(`${op}status:${res.constructor.name}`);
};
}
const connectCallback = function(err){
if (err) {
console.log(`Could not connect:${err}`);
} else {
console.log('Client connected');
// Create a message and send it to the IoT Hub every second
setInterval(()=> {
const windSpeed = 10 + (Math.random() * 4);
const data = JSON.stringify({ deviceId: 'myFirstNodeDevice', windSpeed });
const message = new Message(data);
// 随机发送到路由或默认事件上
if (Math.round(Math.random()) === 1) {
message.properties.add('route', 'test');
}
console.log(`Sending message:${message.getData()}`);
client.sendEvent(message, printResultFor('send'));
}, 1000);
}
};
client.open(connectCallback);
2. IoT Hub 侦听启动
无需修改,直接启动
3. Event Hubs 侦听启动
复制 IoT Hub 侦听源码,修改连接字符串:
const EventHubClient = require('azure-event-hubs').Client;
// const connectionString = 'HostName=[修改连接主机];SharedAccessKeyName=iothubowner;SharedAccessKey=[修改连接密钥]';
const connectionString = 'Endpoint=[sb://修改连接主机.servicebus.chinacloudapi.cn/];SharedAccessKeyName=[修改连接策略];SharedAccessKey=[x修改连接密钥];EntityPath=[事件实体]'
const printError = function(err){
console.log(err.message);
};
const printMessage = function(message){
console.log('Message received: ');
console.log(JSON.stringify(message.body));
console.log(message);
console.log('');
};
const client = EventHubClient.fromConnectionString(connectionString);
client.open()
.then(client.getPartitionIds.bind(client))
.then(partitionIds=> partitionIds.map(partitionId=> client.createReceiver('$Default', partitionId, { startAfterTime: Date.now()}).then((receiver) => {
console.log(`Created partition receiver:${partitionId}`);
receiver.on('errorReceived', printError);
receiver.on('message', printMessage);
})))
.catch(printError);
测试结果
- 发送到默认路由的,只能被IoT Hub侦听应用捕获.
- 发送到刚才配置的测试路由的,只能被Event Hubs侦听应用捕获.
至此,完成路由转发.
以上所述就是小编给大家介绍的《Willin: Azure Node.js IoT Hub开发指南》，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对 码农网 的支持！
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