public static void Main(string[] args)
{
ArgumentHelper helper = new ArgumentHelperBuilder("Push Subscribe Basic Sync", args, Usage)
.DefaultStream("example-stream")
.DefaultSubject("example-subject")
.DefaultCount(0, true) // true indicated 0 means unlimited
// .DefaultDurable("push-sub-basic-sync-durable")
.Build();
int count = helper.Count < 1 ? int.MaxValue : helper.Count;
try
{
using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions()))
{
// The stream (and data) must exist
JsUtils.ExitIfStreamNotExists(c, helper.Stream);
// Create our JetStream context.
IJetStream js = c.CreateJetStreamContext();
// Build our subscription options.
// * A push subscription means the server will "push" us messages.
// * Durable means the server will remember where we are if we use that name.
// * Durable can by null or empty, the builder treats them the same.
// * The stream name is not technically required. If it is not provided, the
// code building the subscription will look it up by making a request to the server.
// If you know the stream name, you might as well supply it and save a trip to the server.
PushSubscribeOptions so = PushSubscribeOptions.Builder()
.WithStream(helper.Stream)
.WithDurable(helper.Durable) // it's okay if this is null, the builder handles it
.Build();
// Subscribe synchronously, then just wait for messages.
IJetStreamPushSyncSubscription sub = js.PushSubscribeSync(helper.Subject, so);
c.Flush(5000);
int red = 0;
while (count > 0)
{
try
{
Msg msg = sub.NextMessage(1000);
Console.WriteLine("\nMessage Received:");
if (msg.HasHeaders)
{
Console.WriteLine(" Headers:");
foreach (string key in msg.Header.Keys)
{
foreach (string value in msg.Header.GetValues(key))
{
Console.WriteLine($" {key}: {value}");
}
}
}
Console.WriteLine(" Subject: {0}\n Data: {1}\n", msg.Subject, Encoding.UTF8.GetString(msg.Data));
Console.WriteLine(" " + msg.MetaData);
// Because this is a synchronous subscriber, there's no auto-ack.
// The default Consumer Configuration AckPolicy is Explicit
// so we need to ack the message or it'll be redelivered.
msg.Ack();
++red;
--count;
}
catch (NATSTimeoutException) // timeout means there are no messages available
{
count = 0; // ran out of messages
}
}
Console.WriteLine("\n" + red + " message(s) were received.\n");
sub.Unsubscribe();
c.Flush(5000);
}
}
catch (Exception ex)
{
helper.ReportException(ex);
}
}
public static void Main(string[] args)
{
ArgumentHelper helper = new ArgumentHelperBuilder("NATS JetStream Push Subscribe Bind Durable", args, Usage)
.DefaultStream("example-stream")
.DefaultSubject("example-subject")
.DefaultDurable("bind-durable")
.DefaultDeliverSubject("bind-deliver")
.DefaultCount(0, true) // true indicated 0 means unlimited
.Build();
int count = helper.Count < 1 ? int.MaxValue : helper.Count;
try
{
using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions()))
{
// The stream (and data) must exist
JsUtils.ExitIfStreamNotExists(c, helper.Stream);
// The durable consumer must already exist. Usually it would be made in configuration
// or via the NATS CLI but we are making it here.
// Important: The consumer must have a deliver subject when made this way or it will be
// understood to be a pull consumer by the server.
// NOTE: If you ran this example already, the consumer will have been created
// This is not a problem if it is exactly the same. Most ConsumerConfiguration
// properties are not modifiable once created.
ConsumerConfiguration cc = ConsumerConfiguration.Builder()
.WithDurable(helper.Durable)
.WithDeliverSubject(helper.DeliverSubject)
.Build();
c.CreateJetStreamManagementContext().AddOrUpdateConsumer(helper.Stream, cc);
// Create our JetStream context.
IJetStream js = c.CreateJetStreamContext();
// bind subscribe to the stream - either variety will work
// V1. Version designed specifically for this purpose.
PushSubscribeOptions so = PushSubscribeOptions.BindTo(helper.Stream, helper.Durable);
// V2. optional long form
// PushSubscribeOptions so = PushSubscribeOptions.Builder()
// .WithBind(true)
// .WithStream(helper.Stream)
// .WithDurable(helper.Durable)
// .Build();
// Subscribe synchronously, then just wait for messages.
IJetStreamPushSyncSubscription sub = js.PushSubscribeSync(helper.Subject, so);
c.Flush(5000);
int red = 0;
while (count > 0)
{
try
{
Msg msg = sub.NextMessage(1000);
Console.WriteLine("\nMessage Received:");
if (msg.HasHeaders)
{
Console.WriteLine(" Headers:");
foreach (string key in msg.Header.Keys)
{
foreach (string value in msg.Header.GetValues(key))
{
Console.WriteLine($" {key}: {value}");
}
}
}
Console.WriteLine(" Subject: {0}\n Data: {1}\n", msg.Subject, Encoding.UTF8.GetString(msg.Data));
Console.WriteLine(" " + msg.MetaData);
// Because this is a synchronous subscriber, there's no auto-ack.
// The default Consumer Configuration AckPolicy is Explicit
// so we need to ack the message or it'll be redelivered.
msg.Ack();
++red;
--count;
}
catch (NATSTimeoutException) // timeout means there are no messages available
{
count = 0; // ran out of messages
}
}
Console.WriteLine("\n" + red + " message(s) were received.\n");
sub.Unsubscribe();
c.Flush(5000);
}
}
catch (Exception ex)
{
helper.ReportException(ex);
}
}