.net core 使用MQTTNET搭建MQTT 服务以及客户端例子
最近项目可能用到MQTT协议故而稍作研究了一下，MQTT协议，基于TCP封装的发布订阅的消息传递机制，理论详情可查看https://blog.csdn.net/qq_28877125/article/details/78325003 这位老兄的总结，废话不多说，先上效果图。
采用.NET体系用的较多的MQTTNET 3.0版本实现，服务端代码如下
try
{
var options = new MqttServerOptions
{
//连接验证
ConnectionValidator = new MqttServerConnectionValidatorDelegate(p =>
{
if (p.ClientId == "SpecialClient")
{
if (p.Username != "USER" || p.Password != "PASS")
{
p.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
}
}
}),
// Storage = new RetainedMessageHandler(),
//消息拦截发送验证
ApplicationMessageInterceptor = new MqttServerApplicationMessageInterceptorDelegate(context =>
{
if (MqttTopicFilterComparer.IsMatch(context.ApplicationMessage.Topic, "/myTopic/WithTimestamp/#"))
{
// Replace the payload with the timestamp. But also extending a JSON
// based payload with the timestamp is a suitable use case.
context.ApplicationMessage.Payload = Encoding.UTF8.GetBytes(DateTime.Now.ToString("O"));
}
if (context.ApplicationMessage.Topic == "not_allowed_topic")
{
context.AcceptPublish = false;
context.CloseConnection = true;
}
}),
///订阅拦截验证
SubscriptionInterceptor = new MqttServerSubscriptionInterceptorDelegate(context =>
{
if (context.TopicFilter.Topic.StartsWith("admin/foo/bar") && context.ClientId != "theAdmin")
{
context.AcceptSubscription = false;
}
if (context.TopicFilter.Topic.StartsWith("the/secret/stuff") && context.ClientId != "Imperator")
{
context.AcceptSubscription = false;
context.CloseConnection = true;
}
})
};
// Extend the timestamp for all messages from clients.
// Protect several topics from being subscribed from every client.
//var certificate = new X509Certificate(@"C:\certs\test\test.cer", "");
//options.TlsEndpointOptions.Certificate = certificate.Export(X509ContentType.Cert);
//options.ConnectionBacklog = 5;
//options.DefaultEndpointOptions.IsEnabled = true;
//options.TlsEndpointOptions.IsEnabled = false;
var mqttServer = new MqttFactory().CreateMqttServer();
mqttServer.ApplicationMessageReceivedHandler = new MqttApplicationMessageReceivedHandlerDelegate(e =>
{
Console.WriteLine(
$"'{e.ClientId}' reported '{e.ApplicationMessage.Topic}' > '{Encoding.UTF8.GetString(e.ApplicationMessage.Payload ?? new byte[0])}'",
ConsoleColor.Magenta);
});
//options.ApplicationMessageInterceptor = c =>
//{
// if (c.ApplicationMessage.Payload == null || c.ApplicationMessage.Payload.Length == 0)
// {
// return;
// }
// try
// {
// var content = JObject.Parse(Encoding.UTF8.GetString(c.ApplicationMessage.Payload));
// var timestampProperty = content.Property("timestamp");
// if (timestampProperty != null && timestampProperty.Value.Type == JTokenType.Null)
// {
// timestampProperty.Value = DateTime.Now.ToString("O");
// c.ApplicationMessage.Payload = Encoding.UTF8.GetBytes(content.ToString());
// }
// }
// catch (Exception)
// {
// }
//};
//开启订阅以及取消订阅
mqttServer.ClientSubscribedTopicHandler = new MqttServerClientSubscribedHandlerDelegate(MqttServer_SubscribedTopic);
mqttServer.ClientUnsubscribedTopicHandler = new MqttServerClientUnsubscribedTopicHandlerDelegate(MqttServer_UnSubscribedTopic);
//客户端连接事件
mqttServer.UseClientConnectedHandler( MqttServer_ClientConnected);
//客户端断开事件
mqttServer.UseClientDisconnectedHandler(MqttServer_ClientDisConnected);
await mqttServer.StartAsync(options);
Console.WriteLine("服务启动成功,输入任意内容并回车停止服务");
Console.ReadLine();
await mqttServer.StopAsync();
}
catch (Exception e)
{
Console.WriteLine(e);
}
Console.ReadLine();客户端代码如下：
// Create a new MQTT client.
var factory = new MqttFactory();
mqttClient = factory.CreateMqttClient();
// Create TCP based options using the builder.
var options = new MqttClientOptionsBuilder()
.WithClientId(clientId)
.WithCredentials(user, pwd)//用户名 密码
.WithCleanSession()
.WithTcpServer("127.0.0.1", 1883) // Port is optional TCP 服务
// .WithTls(
//new MqttClientOptionsBuilderTlsParameters
//{
// UseTls = true,
// CertificateValidationCallback = (X509Certificate x, X509Chain y, SslPolicyErrors z, IMqttClientOptions o) =>
// {
// // TODO: Check conditions of certificate by using above parameters.
// return true;
// },
//})//类型 TCPS
.Build();
//重连机制
mqttClient.UseDisconnectedHandler(async e =>
{
Console.WriteLine("### DISCONNECTED FROM SERVER ###");
await Task.Delay(TimeSpan.FromSeconds(3));
try
{
await mqttClient.ConnectAsync(options, CancellationToken.None); // Since 3.0.5 with CancellationToken
}
catch
{
Console.WriteLine("### RECONNECTING FAILED ###");
}
});
//消费消息
mqttClient.UseApplicationMessageReceivedHandler(e =>
{
Console.WriteLine("### RECEIVED APPLICATION MESSAGE ###");
Console.WriteLine($"+ Topic = {e.ApplicationMessage.Topic}");//主题
Console.WriteLine($"+ Payload = {Encoding.UTF8.GetString(e.ApplicationMessage.Payload)}");//页面信息
Console.WriteLine($"+ QoS = {e.ApplicationMessage.QualityOfServiceLevel}");//消息等级
Console.WriteLine($"+ Retain = {e.ApplicationMessage.Retain}");//是否保留
Console.WriteLine();
// Task.Run(() => mqttClient.PublishAsync("hello/world"));
});
//连接成功触发订阅主题
mqttClient.UseConnectedHandler(async e =>
{
Console.WriteLine($"### 成功连接 ###");
// Subscribe to a topic
//await mqttClient.SubscribeAsync(new TopicFilterBuilder().WithTopic("my/topic").Build());
//Console.WriteLine("### SUBSCRIBED ###");
});
try
{
await mqttClient.ConnectAsync(options, CancellationToken.None);
bool isExit = false;
while (!isExit)
{
Console.WriteLine(@"请输入
1.订阅主题
2.取消订阅
3.发送消息
4.退出输入exit");
var input = Console.ReadLine();
switch (input)
{
case "1":
Console.WriteLine(@"请输入主题名称：");
var topicName = Console.ReadLine();
await SubscribedTopic(topicName);
break;
case "2":
Console.WriteLine(@"请输入需要取消订阅主题名称：");
topicName = Console.ReadLine();
await UnsubscribedTopic(topicName);
break;
case "3":
Console.WriteLine("请输入需要发送的主题名称");
topicName = Console.ReadLine();
Console.WriteLine("请输入需要发送的消息");
var message = Console.ReadLine();
await PublishMessageAsync(new MQTTMessageModel() { Payload = message, Topic = topicName, Retain = true });
break;
case "exit":
isExit = true;
break;
default:
Console.WriteLine("请输入正确指令！");
break;
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
Console.ReadLine();
}服务端以及客户端都是core 3.1需要的小伙伴可以下载完整例子参考。