public void Create_ServerOptionsBuilder()
{
var factory = new MqttFactory();
var builder = factory.CreateServerOptionsBuilder();
Assert.IsNotNull(builder);
}
static async Task <MqttServer> StartMqttServer()
{
var mqttFactory = new MqttFactory();
// Due to security reasons the "default" endpoint (which is unencrypted) is not enabled by default!
var mqttServerOptions = mqttFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
var server = mqttFactory.CreateMqttServer(mqttServerOptions);
await server.StartAsync();
return(server);
}
public static async Task Persist_Retained_Messages()
{
/*
* This sample starts a simple MQTT server which will store all retained messages in a file.
*/
var storePath = Path.Combine(Path.GetTempPath(), "RetainedMessages.json");
var mqttFactory = new MqttFactory();
// Due to security reasons the "default" endpoint (which is unencrypted) is not enabled by default!
var mqttServerOptions = mqttFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
using (var server = mqttFactory.CreateMqttServer(mqttServerOptions))
{
// Make sure that the server will load the retained messages.
server.LoadingRetainedMessageAsync += async eventArgs =>
{
try
{
eventArgs.LoadedRetainedMessages = await JsonSerializer.DeserializeAsync <List <MqttApplicationMessage> >(File.OpenRead(storePath));
Console.WriteLine("Retained messages loaded.");
}
catch (FileNotFoundException)
{
// Ignore because nothing is stored yet.
Console.WriteLine("No retained messages stored yet.");
}
catch (Exception exception)
{
Console.WriteLine(exception);
}
};
// Make sure to persist the changed retained messages.
server.RetainedMessageChangedAsync += async eventArgs =>
{
try
{
// This sample uses the property _StoredRetainedMessages_ which will contain all(!) retained messages.
// The event args also contain the affected retained message (property ChangedRetainedMessage). This can be
// used to write all retained messages to dedicated files etc. Then all files must be loaded and a full list
// of retained messages must be provided in the loaded event.
var buffer = JsonSerializer.SerializeToUtf8Bytes(eventArgs.StoredRetainedMessages);
await File.WriteAllBytesAsync(storePath, buffer);
Console.WriteLine("Retained messages saved.");
}
catch (Exception exception)
{
Console.WriteLine(exception);
}
};
// Make sure to clear the retained messages when they are all deleted via API.
server.RetainedMessagesClearedAsync += _ =>
{
File.Delete(storePath);
return(Task.CompletedTask);
};
await server.StartAsync();
Console.WriteLine("Press Enter to exit.");
Console.ReadLine();
}
}
