### Minimal ASP.NET Core Setup

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

This example demonstrates registering ArtemisNetClient services and configuring a connection, consumer, and producer within an ASP.NET Core application. Ensure AddActiveMqHostedService is called to automatically start consumers and producers.

```csharp
var builder = WebApplication.CreateBuilder(args);

builder.Services.AddActiveMqHostedService();

var endpoint = Endpoint.Create(
    host: "localhost",
    port: 5672,
    user: "artemis",
    password: "artemis");

var activeMq = builder.Services.AddActiveMq(
    name: "my-artemis",
    endpoints: new[] { endpoint });

activeMq.AddConsumer(
    address: "orders.incoming",
    routingType: RoutingType.Anycast,
    handler: async (message, consumer, serviceProvider, cancellationToken) =>
    {
        var publisher = serviceProvider.GetRequiredService<OrderEventsProducer>();
        var orderId = message.GetBody<string>();

        await publisher.PublishAccepted(orderId, cancellationToken);
        await consumer.AcceptAsync(message);
    });

activeMq.AddProducer<OrderEventsProducer>("orders.events", RoutingType.Multicast);

var app = builder.Build();
app.Run();

public sealed class OrderEventsProducer
{
    private readonly IProducer _producer;

    public OrderEventsProducer(IProducer producer) => _producer = producer;

    public Task PublishAccepted(string orderId, CancellationToken cancellationToken)
    {
        return _producer.SendAsync(new Message($"accepted:{orderId}"), cancellationToken);
    }

}
```

--------------------------------

### Install Hosting Package

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

For ASP.NET Core or generic hosted applications, install the hosting package in addition to the DI package.

```bash
dotnet add package ArtemisNetClient.Extensions.Hosting
```

--------------------------------

### Add ArtemisNetClient.Testing NuGet Package

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/testing

Install the ArtemisNetClient.Testing NuGet package using the dotnet CLI.

```bash
dotnet add package ArtemisNetClient.Testing  
```

--------------------------------

### Complete Example: Multi-Criteria Filtering

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Demonstrates a complete scenario of creating a consumer with a complex filter expression and sending messages, illustrating which messages are received based on the criteria. This example showcases the practical application of combined filtering logic.

```csharp
await using var connection = await connectionFactory.CreateAsync(endpoint);
var address = "orders";

// Create consumer that only receives high-priority, pending orders for the premium tier  
await using var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration
{
    Address = address,
    RoutingType = RoutingType.Anycast,
    FilterExpression = "AMQPriority >= 7 AND status = 'pending' AND tier = 'premium'"
});

// Create producer and send various messages  
await using var producer = await connection.CreateProducerAsync(address, RoutingType.Anycast);

// This message will be received (matches all criteria)  
await producer.SendAsync(new Message("order1")
{
    Priority = 9,
    ApplicationProperties =
    {
        ["status"] = "pending",
        ["tier"] = "premium"
    }
});

// This message will NOT be received (priority too low)  
await producer.SendAsync(new Message("order2")
{
    Priority = 4,
    ApplicationProperties =
    {
        ["status"] = "pending",
        ["tier"] = "premium"
    }
});

// This message will NOT be received (wrong status)  
await producer.SendAsync(new Message("order3")
{
    Priority = 8,
    ApplicationProperties =
    {
        ["status"] = "completed",
        ["tier"] = "premium"
    }
});

var message = await consumer.ReceiveAsync(cancellationToken);
Console.WriteLine(message.GetBody<string>()); // Output: "order1"
```

--------------------------------

### Install ActiveMQ.Artemis.Client NuGet Package

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Use the dotnet CLI to add the ActiveMQ.Artemis.Client NuGet package to your project.

```bash
dotnet add package ArtemisNetClient  
```

--------------------------------

### Install DI-only Package

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Use this command to add the dependency injection extensions package for ArtemisNetClient.

```bash
dotnet add package ArtemisNetClient.Extensions.DependencyInjection
```

--------------------------------

### Enable Topology Declaration for Consumers

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Enable queue and address declaration when the application starts. This is useful for ensuring that messaging infrastructure is set up automatically.

```csharp
activeMq  
    .AddConsumer(  
        address: "orders.incoming",  
        routingType: RoutingType.Anycast,  
        queue: "orders-service",  
        handler: async (message, consumer, serviceProvider, cancellationToken) =>  
        {  
            await consumer.AcceptAsync(message);  
        })  
    .EnableQueueDeclaration()  
    .EnableAddressDeclaration();  
```

--------------------------------

### Configure Linear Backoff Recovery Policy

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Use Linear Backoff for connection recovery with delays that increase linearly. This example sets 5 retries with initial delays of 100, 200, 300, 400, and 500ms.

```csharp
var linearBackoff = RecoveryPolicyFactory.LinearBackoff(
    initialDelay: TimeSpan.FromMilliseconds(100),
    retryCount: 5);

```

--------------------------------

### Configure Linear Backoff with Custom Factor

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Customize the linear backoff delay by specifying a growth factor. This example uses a factor of 2, resulting in delays of 100, 300, 500, 700, and 900ms.

```csharp
var linearBackoff = RecoveryPolicyFactory.LinearBackoff(
    initialDelay: TimeSpan.FromMilliseconds(100),
    retryCount: 5,
    factor: 2);

```

--------------------------------

### Configure Exponential Backoff with Custom Factor

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Customize the exponential backoff delay by specifying a growth factor. This example uses a factor of 4.0, resulting in delays of 100, 200, 400, 800, and 1600ms.

```csharp
var exponentialBackoff = RecoveryPolicyFactory.ExponentialBackoff(
    initialDelay: TimeSpan.FromMilliseconds(100),
    retryCount: 5,
    factor: 4.0);

```

--------------------------------

### Configure Exponential Backoff Recovery Policy

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Use Exponential Backoff for connection recovery where delays increase exponentially (initialDelay x 2^attempt). This example sets 5 retries with an initial delay of 100ms.

```csharp
var exponentialBackoff = RecoveryPolicyFactory.ExponentialBackoff(
    initialDelay: TimeSpan.FromMilliseconds(100),
    retryCount: 5);

```

--------------------------------

### Configure Constant Backoff Recovery Policy

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Use Constant Backoff to retry connection recovery with a fixed delay between attempts. This example sets 5 retries with a 1-second delay.

```csharp
var constantBackoff = RecoveryPolicyFactory.ConstantBackoff(
    delay: TimeSpan.FromSeconds(1),
    retryCount: 5);

```

--------------------------------

### Demonstrate NoLocal Filter Functionality

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

This example illustrates the NoLocal filter by sending messages from two different connections to the same multicast address. The consumer, configured with NoLocalFilter=true on connection 1, will only receive the message sent from connection 2, effectively filtering out its own connection's message.

```csharp
var address = "news.updates";

// Create first connection with producer and consumer
await using var connection1 = await connectionFactory.CreateAsync(endpoint);
await using var producer1 = await connection1.CreateProducerAsync(address, RoutingType.Multicast);
await using var consumer = await connection1.CreateConsumerAsync(new ConsumerConfiguration

{

    Address = address,

    RoutingType = RoutingType.Multicast,

    NoLocalFilter = true

});

// Create second connection with producer
await using var connection2 = await connectionFactory.CreateAsync(endpoint);
await using var producer2 = await connection2.CreateProducerAsync(address, RoutingType.Multicast);

// Send messages from both connections
await producer1.SendAsync(new Message("from connection 1"));
await producer2.SendAsync(new Message("from connection 2"));

// Consumer will only receive the message from connection 2
var message = await consumer.ReceiveAsync(cancellationToken);
Console.WriteLine(message.GetBody<string>()); // Output: "from connection 2"
```

--------------------------------

### Retrieve Message Payload

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-payload

Get the message body by specifying the expected type `T`. Returns `default(T)` if the type does not match the payload type.

```csharp
var body = message.GetBody<T>();
```

--------------------------------

### Configure Fast First Recovery Policy

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Enable immediate recovery after the first connection failure by setting `fastFirst: true` in the recovery policy factory.

```csharp
var recoveryPolicy = RecoveryPolicyFactory.ExponentialBackoff(

    initialDelay: TimeSpan.FromMilliseconds(100),

    retryCount: 5,

    factor: 4.0,

    fastFirst: true);

```

--------------------------------

### Configure Failover with Multiple Endpoints

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Set up failover by providing a list of endpoints to `ConnectionFactory.CreateAsync`. The client will attempt to reconnect to subsequent endpoints in a round-robin fashion if a connection is lost.

```csharp
var masterEndpoint = Endpoint.Create(

    host: "master",

    port: 5672,

    user: "guest",

    password: "guest",

    scheme: Scheme.Amqp);
var slaveEndpoint = Endpoint.Create(

    host: "slave",

    port: 5672,

    user: "guest",

    password: "guest",

    scheme: Scheme.Amqp);
var connectionFactory = new ConnectionFactory();
var connection = await connectionFactory.CreateAsync(new[]

{

    masterEndpoint,

    slaveEndpoint

});

```

--------------------------------

### Request Side Registration (Dependency Injection)

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/request-reply

Register `IRequestReplyClient` with `AddRequestReplyClient<TClient>()` and `AddActiveMqHostedService()` for automatic startup in hosted applications.

```csharp
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddActiveMqHostedService();
  
var endpoint = Endpoint.Create("localhost", 5672, "guest", "guest");
var activeMq = builder.Services.AddActiveMq("bookstore-cluster", new[] { endpoint });
activeMq.AddRequestReplyClient<BookstoreRequestClient>();
  
public sealed class BookstoreRequestClient  
{
    private readonly IRequestReplyClient _requestReplyClient;

    public BookstoreRequestClient(IRequestReplyClient requestReplyClient)
    {
        _requestReplyClient = requestReplyClient;
    }

    public Task<Message> SendAsync(string payload, CancellationToken cancellationToken)
    {
        return _requestReplyClient.SendAsync(
            "bookstore.requests",
            RoutingType.Anycast,
            new Message(payload),
            cancellationToken);
    }

}

```

--------------------------------

### Create an IConsumer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Create an IConsumer instance to receive messages from a specific queue. Ensure the connection is established before creating the consumer.

```csharp
var consumer = await connection.CreateConsumerAsync("a1", RoutingType.Anycast);
```

--------------------------------

### Configure Connection Events

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Set up event handlers for the created IConnection, such as listening for connection closed events. This allows for custom logic when the connection state changes.

```csharp
activeMq.ConfigureConnection((_, connection) =>  
{  
    connection.ConnectionClosed += (_, args) =>  
    {  
        Console.WriteLine($"Connection closed. Error={args.Error}");  
    };  
});  
```

--------------------------------

### Establish a Connection to Artemis Broker

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Instantiate a ConnectionFactory and use it to asynchronously create a connection to the specified Artemis broker endpoint.

```csharp
var connectionFactory = new ConnectionFactory();  
var endpoint = Endpoint.Create("localhost", 5672, "guest", "guest");  
var connection = await connectionFactory.CreateAsync(endpoint);  
```

--------------------------------

### Response Side Implementation (Core Client)

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/request-reply

Create a consumer to receive requests. When sending a reply, ensure the `ReplyTo` address and `CorrelationId` from the incoming message are used.

```csharp
var connectionFactory = new ConnectionFactory();  

var endpoint = Endpoint.Create("localhost", 5672, "guest", "guest");  

var connection = await connectionFactory.CreateAsync(endpoint);  

await using var consumer = await connection.CreateConsumerAsync("my-address", RoutingType.Anycast);  

var request = await consumer.ReceiveAsync();  

await using var producer = await connection1.CreateAnonymousProducerAsync();  

await producer.SendAsync(request.ReplyTo, new Message("bar")  

{  

    CorrelationId = request.CorrelationId  

});  

await consumer.AcceptAsync(request);  

```

--------------------------------

### Import ActiveMQ.Artemis.Client Namespace

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Import the necessary namespace to use the core API interfaces and classes for the .NET Client for Apache Artemis.

```csharp
using ActiveMQ.Artemis.Client;  
```

--------------------------------

### Request Side Implementation (Core Client)

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/request-reply

Use `IRequestReplyClient` to send messages and asynchronously listen for responses. Ensure the connection and client are properly disposed.

```csharp
var connectionFactory = new ConnectionFactory();  

var endpoint = Endpoint.Create("localhost", 5672, "guest", "guest");  

var connection = await connectionFactory.CreateAsync(endpoint);  

await using var requestReplyClient = await connection.CreateRequestReplyClientAsync();  

var response = await requestReplyClient.SendAsync("my-address", RoutingType.Anycast, new Message("foo"), default);  

var test = response.GetBody<string>(); // bar  

```

--------------------------------

### Import Namespaces

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

These are the essential namespaces to import when using ArtemisNetClient's dependency injection and hosting extensions.

```csharp
using ActiveMQ.Artemis.Client;

using ActiveMQ.Artemis.Client.Extensions.DependencyInjection;

using ActiveMQ.Artemis.Client.Extensions.Hosting;
```

--------------------------------

### Create an Endpoint Configuration

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Configure the connection endpoint for an Artemis broker, specifying host, port, user, password, and security scheme.

```csharp
Endpoint.Create(  
    host: "localhost",  
    port: 5672,  
    user: "guest",  
    password: "guest",  
    scheme: Scheme.Amqp);  
```

--------------------------------

### Response Side Registration (Dependency Injection)

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/request-reply

Register a consumer for incoming requests and an anonymous producer for replies. The handler must use `message.ReplyTo` and copy `message.CorrelationId`.

```csharp
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddActiveMqHostedService();
  
var endpoint = Endpoint.Create("localhost", 5672, "guest", "guest");
var activeMq = builder.Services.AddActiveMq("bookstore-cluster", new[] { endpoint });
  
activeMq.AddAnonymousProducer<ReplyProducer>();
activeMq.AddConsumer(
    address: "bookstore.requests",
    routingType: RoutingType.Anycast,
    handler: async (message, consumer, serviceProvider, cancellationToken) =>
    {
        var replyProducer = serviceProvider.GetRequiredService<ReplyProducer>();

        await replyProducer.SendAsync(
            message.ReplyTo,
            new Message("accepted")
            {
                CorrelationId = message.CorrelationId
            },
            cancellationToken);

        await consumer.AcceptAsync(message);
    });
  
public sealed class ReplyProducer  
{
    private readonly IAnonymousProducer _producer;

    public ReplyProducer(IAnonymousProducer producer)
    {
        _producer = producer;
    }

    public Task SendAsync(string address, Message message, CancellationToken cancellationToken)
    {
        return _producer.SendAsync(address, message, cancellationToken);
    }

}

```

--------------------------------

### Creating a Producer for a Specific Address

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Use IProducer to send messages to a specific address and routing type. Create producers once and reuse them for efficiency.

```csharp
var producer = await connection.CreateProducerAsync("a1", RoutingType.Anycast);
```

--------------------------------

### Configure Linear Backoff with Max Delay

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Set a maximum delay for linear backoff when using an infinite number of retries. This prevents excessively long waits between recovery attempts.

```csharp
var linearBackoff = RecoveryPolicyFactory.LinearBackoff(
    initialDelay: TimeSpan.FromMilliseconds(100),
    maxDelay: TimeSpan.FromSeconds(15));

```

--------------------------------

### Create a New Message

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-payload

Instantiate a new `Message` object with a string payload.

```csharp
var message = new Message("foo");
```

--------------------------------

### Configure Connection Factory Settings

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Customize the connection factory for transport, logging, recovery, or message ID settings. This is done by providing a configuration delegate to ConfigureConnectionFactory.

```csharp
activeMq.ConfigureConnectionFactory((serviceProvider, factory) =>  
{  
    factory.LoggerFactory = serviceProvider.GetRequiredService<ILoggerFactory>();  
    factory.AutomaticRecoveryEnabled = true;  
});  
```

--------------------------------

### Handle Request-Reply Messages and Send Response

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Configure a consumer to handle incoming requests, process them, and send a reply. The reply must include the original message's CorrelationId and be sent to the message.ReplyTo address.

```csharp
activeMq.AddAnonymousProducer<ReplyProducer>();  

activeMq.AddConsumer(  
    address: "bookstore.requests",  
    routingType: RoutingType.Anycast,  
    handler: async (message, consumer, serviceProvider, cancellationToken) =>  
    {  
        var replyProducer = serviceProvider.GetRequiredService<ReplyProducer>();  

        await replyProducer.SendAsync(  
            message.ReplyTo,  
            new Message("ok")  
            {
                CorrelationId = message.CorrelationId  
            },  
            cancellationToken);  

        await consumer.AcceptAsync(message);  
    });  
```

--------------------------------

### Subscribing to Connection Recovery Errors

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Demonstrates how to subscribe to the ConnectionRecoveryError event to react when the client fails to reestablish a connection after a network interruption.

```csharp
var connectionFactory = new ConnectionFactory();  

var connection = await connectionFactory.CreateAsync(endpoint);  

connection.ConnectionRecoveryError += (sender, eventArgs) =>  

{

    // react accordingly  

};

```

--------------------------------

### Configure Message Credit for a Consumer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/consumer-credit

Set the message credit for a new consumer during its creation. The credit value must be at least 1. This configuration limits the number of messages a consumer can receive before acknowledging them.

```csharp
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{

    Address = address,

    RoutingType = RoutingType.Multicast,

    Credit = 2 // Set message credit to 2

});  

```

--------------------------------

### Configure ASP.NET Core Application with ArtemisNetClient

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/testing

This code configures an ASP.NET Core application to use ArtemisNetClient for messaging, including setting up a hosted service, defining endpoints, and configuring a consumer and producer.

```csharp
var builder = WebApplication.CreateBuilder(args);

builder.Services.AddActiveMqHostedService();

  

var endpoint = Endpoint.Create(
  
    host: "localhost",  

    port: 5672,  

    "artemis",  

    "artemis"

);

var activeMqBuilder = builder.Services.AddActiveMq(name: "my-artemis", endpoints: new[] {endpoint});
activeMqBuilder.AddConsumer(address: "foo", routingType: RoutingType.Anycast,  

    handler: async (message, consumer, serviceProvider, cancellationToken) =>  

    {
  
        var body = message.GetBody<string>();
  

        var bar = body + "-" + "bar";
  

        var producer = serviceProvider.GetRequiredService<MyProducer>();

        await producer.Publish(bar, cancellationToken);
  

        await consumer.AcceptAsync(message);

    });
activeMqBuilder.AddProducer<MyProducer>("bar", RoutingType.Multicast);

  

  

var app = builder.Build();
  

app.Run();
  

// this is required so we can use WebApplicationFactory to run the test server
public partial class Program { }
```

--------------------------------

### Sending a Message with a Producer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Send a message using a pre-configured producer. Messages sent this way are automatically routed based on the producer's configuration.

```csharp
await producer.SendAsync(new Message("foo"));
```

--------------------------------

### Register Typed Request-Reply Client

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Register a typed wrapper for IRequestReplyClient to simplify sending requests. Ensure the client class has a constructor accepting IRequestReplyClient.

```csharp
activeMq.AddRequestReplyClient<BookstoreRequestClient>();  

public sealed class BookstoreRequestClient  
{  
    private readonly IRequestReplyClient _client;  

    public BookstoreRequestClient(IRequestReplyClient client) => _client = client;  

    public Task<Message> SendAsync(string address, string payload, CancellationToken cancellationToken)  
    {  
        return _client.SendAsync(  
            address,  
            RoutingType.Anycast,  
            new Message(payload),  
            cancellationToken);  
    }  
}
```

--------------------------------

### Register Typed Producer for Order Events

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Register a typed producer for a specific address and routing type. The wrapper type is transient by default, but can be configured as Singleton or Scoped.

```csharp
activeMq.AddProducer<OrderEventsProducer>("orders.events", RoutingType.Multicast);

public sealed class OrderEventsProducer
{
    private readonly IProducer _producer;

    public OrderEventsProducer(IProducer producer) => _producer = producer;

    public Task PublishAccepted(string orderId, CancellationToken cancellationToken)
    {
        return _producer.SendAsync(new Message($"accepted:{orderId}"), cancellationToken);
    }
}
```

--------------------------------

### Send and Filter by Custom Application Property

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Send messages with custom application properties and then filter consumers based on these properties. This allows for flexible message routing.

```csharp
// Sending a message with custom properties  
await producer.SendAsync(new Message("order data")  

{
  
    ApplicationProperties =  

    {
  
        ["color"] = "red",
  
        ["size"] = "large",
  
        ["quantity"] = 10

    }

});  
  
// Filtering by custom property  
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{
  
    Address = address,
  
    RoutingType = RoutingType.Anycast,
  
    FilterExpression = "color = 'red'"

});  
```

--------------------------------

### Integration Test for ASP.NET Core Application with TestKit

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/testing

This integration test uses TestKit to spin up an in-memory broker and Microsoft.AspNetCore.Mvc.Testing to test an ASP.NET Core application. It sends a message, subscribes to an address, and asserts the received message content.

```csharp
public class MyTests
{
    [Fact]
    public async Task Test()
    {
        // setup the test kit

        var endpoint = Endpoint.Create(

            host: "localhost",

            port: 5672,

            "artemis",

            "artemis"

        );

        using var testKit = new TestKit(endpoint);
          

        // setup the application

        await using var application = new WebApplicationFactory<Program>();
  

        // trigger the app to start

        application.CreateClient();
  

        // subscribe to the bar address

        using var subscription = testKit.Subscribe("bar");
          

        // send a message to the application

        await testKit.SendMessageAsync("foo", new Message("my-payload"));
  

        // wait for a message sent from the application

        var message = await subscription.ReceiveAsync();
          

        Assert.Equal("my-payload-bar", message.GetBody<string>());

    }

}
```

--------------------------------

### Check if Connection is Open

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/connection-lifecycle

Use the IsOpened property to check the current status of the connection to the broker. This helps in determining if the connection is still active.

```csharp
var connectionFactory = new ConnectionFactory();  

var connection = await connectionFactory.CreateAsync(endpoint);  

if (connection.IsOpened)  

{  

    // connection is still opened  

}  

else  

{  

    // connection to the broker has been lost  

}  
```

--------------------------------

### Accept Message

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-acknowledgment

Use AcceptAsync to signal successful message processing to the broker. The broker typically removes the message from the queue for destructive queues.

```csharp
var message = await consumer.ReceiveAsync();

// process message...  

await consumer.AcceptAsync(message);
```

--------------------------------

### Combine Filter Expression and NoLocal Filter

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Use this configuration to create a consumer that receives messages with a 'priority' greater than 5 and originating from a different connection. Ensure the ActiveMQ Artemis client library is imported.

```csharp
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{

    Address = address,

    RoutingType = RoutingType.Multicast,

    FilterExpression = "priority > 5",

    NoLocalFilter = true  

});  

```

--------------------------------

### Pattern Matching with LIKE Operator

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Utilize the LIKE operator with wildcard characters ('%' for any sequence of characters, '_' for a single character) for flexible string matching. This is ideal for partial string comparisons.

```csharp
// Match departments starting with 'sales'  
FilterExpression = "department LIKE 'sales%'"
```

```csharp
// Match emails ending with '@example.com'  
FilterExpression = "email LIKE '%@example.com'"
```

```csharp
// Match code patterns: 'A', any character, then 'B' (e.g., 'AXB', 'A1B')  
FilterExpression = "code LIKE 'A_B'"
```

--------------------------------

### Configuring Producer for Nondurable Messages

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-durability

Configures a producer to send nondurable messages by default. This reduces overhead and prioritizes performance over reliability, offering at-most-once delivery guarantees.

```csharp
var producer = await connection.CreateProducerAsync(new ProducerConfiguration  

{

    Address = "a1",

    RoutingType = RoutingType.Anycast,

    MessageDurabilityMode = DurabilityMode.Nondurable

});
```

--------------------------------

### Creating an Anonymous Producer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Instantiate an IAnonymousProducer to send messages without pre-defining a target address. This is useful for dynamic routing scenarios.

```csharp
var anonymousProducer = await connection.CreateAnonymousProducer();
```

--------------------------------

### Register Anonymous Producer for Dynamic Replies

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Register an anonymous producer when the producer needs to publish to multiple addresses dynamically. The wrapper type is transient by default.

```csharp
activeMq.AddAnonymousProducer<ReplyProducer>();

public sealed class ReplyProducer
{
    private readonly IAnonymousProducer _producer;

    public ReplyProducer(IAnonymousProducer producer) => _producer = producer;

    public Task SendAsync(string address, Message message, CancellationToken cancellationToken)
    {
        return _producer.SendAsync(address, message, cancellationToken);
    }
}
```

--------------------------------

### Configure TCP Keep-Alive Settings

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/connection-lifecycle

Configure TCP Keep-Alive settings on the ConnectionFactory to enhance connection stability. This sends periodic signals to ensure the connection remains active.

```csharp
var factory = new ConnectionFactory();  

// Configure TCP Keep-Alive settings  

factory.TCP.KeepAliveTime = 30000; // 30 seconds  

factory.TCP.KeepAliveInterval = 1000; // 1 second  
```

--------------------------------

### Create Consumer with Filter Expression

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Use this configuration to create a consumer that only receives messages matching a specific property value.

```csharp
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{
  
    Address = address,
  
    RoutingType = RoutingType.Multicast,
  
    FilterExpression = "color = 'red'"

});  
```

--------------------------------

### Sending a Durable Message

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-durability

Demonstrates sending a durable message using the SendAsync method. Durable messages are persisted by the broker before acknowledgment, ensuring at-least-once delivery semantics.

```csharp
await producer.SendAsync(new Message("foo"))
```

--------------------------------

### Sending a Message with an Anonymous Producer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Send a message using an anonymous producer, specifying the address and routing type at the time of sending. This provides flexibility for routing.

```csharp
await anonymousProducer.SendAsync("a2", RoutingType.Multicast, new Message("foo"));
```

--------------------------------

### Add ActiveMQ Consumer with Handler

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/dependency-injection

Registers a message consumer for a specified address and routing type. The handler processes incoming messages and acknowledges them.

```csharp
activeMq.AddConsumer(
    address: "orders.incoming",
    routingType: RoutingType.Anycast,
    handler: async (message, consumer, serviceProvider, cancellationToken) =>
    {
        var logger = serviceProvider.GetRequiredService<ILogger<Program>>();
        logger.LogInformation("Received order {OrderId}", message.GetBody<string>());

        await consumer.AcceptAsync(message);
    });

```

--------------------------------

### Receive a Message

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Retrieve a message from the consumer's buffer. If no messages are available, this method will asynchronously wait until a new message arrives.

```csharp
var message = await consumer.ReceiveAsync();
```

--------------------------------

### Configure NoLocal Filter in Consumer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Set the 'NoLocalFilter' property to 'true' within the ConsumerConfiguration to enable this feature. This configuration is essential for preventing self-consumption of messages in multicast scenarios.

```csharp
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{

    Address = address,

    RoutingType = RoutingType.Multicast,

    NoLocalFilter = true

});
```

--------------------------------

### Set Default Message Priority on Producer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-priority

Configure a message producer to send all messages with a specific priority by default. This is useful for establishing a baseline importance for messages from a particular source.

```csharp
var producer = await connection.CreateProducerAsync(new ProducerConfiguration  

{

    Address = "a1",

    RoutingType = RoutingType.Anycast,

    MessagePriority = 9

});
```

--------------------------------

### Sending Multiple Messages Transactionally

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/transactions

Use this pattern to send a series of messages as a single atomic unit. All messages will be delivered only after `CommitAsync` is called. If any part of the operation fails, no messages will be delivered.

```csharp
var connectionFactory = new ConnectionFactory();  

var endpoint = Endpoint.Create("localhost", 5672, "guest", "guest");  

var connection = await connectionFactory.CreateAsync(endpoint);  

  

await using (var transaction = new Transaction())  
{  
    await producer.SendAsync(  
        address: "credit-queue",  
        message: new Message("credit:500,account:a"),  
        transaction: transaction  
    );  
    await producer.SendAsync(  
        address: "debit-queue",  
        message: new Message("debit:500,account:b"),  
        transaction: transaction);
  
    await transaction.CommitAsync();  
}  

```

--------------------------------

### Handle Connection Closed Event

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/connection-lifecycle

Subscribe to the ConnectionClosed event to be notified when the connection to the broker is lost. This allows your application to react accordingly.

```csharp
var connectionFactory = new ConnectionFactory();  

var connection = await connectionFactory.CreateAsync(endpoint);  

connection.ConnectionClosed += (sender, eventArgs) =>  

{  

    // react accordingly  

};  
```

--------------------------------

### Receive a Message with Cancellation

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Receive a message while allowing for cancellation. This is useful for gracefully shutting down the application by providing a CancellationToken.

```csharp
var cts = new CancellationTokenSource();

var message = await consumer.ReceiveAsync(cts.Token);
```

--------------------------------

### Reject Message

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-acknowledgment

Use Reject to inform the broker that a message cannot be processed. Rejected messages may be routed to the Dead Letter Queue (DLQ) if configured.

```csharp
var message = await consumer.ReceiveAsync();  

consumer.Reject(message);
```

--------------------------------

### Filter with Combined Operators

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Construct sophisticated filters by nesting logical operators like AND and OR within parentheses to control the order of evaluation. This allows for complex filtering logic.

```csharp
FilterExpression = "AMQPriority > 5 AND (color = 'red' OR color = 'blue')"
```

```csharp
FilterExpression = "quantity BETWEEN 10 AND 100 AND status = 'pending'"
```

--------------------------------

### Handle Message Delivery Count

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-acknowledgment

Check the DeliveryCount property to manage message retries. If the count exceeds a threshold, reject the message; otherwise, retry by modifying it.

```csharp
var message = await consumer.ReceiveAsync();  

if (message.DeliveryCount >= 3)  

{

    // too many retries, reject to DLQ  

    consumer.Reject(message);

}

else  

{

    // retry later  

    consumer.Modify(message, deliveryFailed: true, undeliverableHere: false);

}
```

--------------------------------

### IRecoveryPolicy Interface Definition

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Defines the interface for configuring automatic recovery behavior, including the maximum number of retry attempts and the delay between attempts.

```csharp
public interface IRecoveryPolicy  

{

    int RetryCount { get; }

    TimeSpan GetDelay(int attempt);

}

```

--------------------------------

### Filter by AMQDurable

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Filter messages based on their durability mode. Use 'DURABLE' for persistent messages and 'NON_DURABLE' for transient ones.

```csharp
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{
  
    Address = address,
  
    RoutingType = RoutingType.Anycast,
  
    FilterExpression = "AMQDurable = 'DURABLE'"

});  
```

--------------------------------

### Inspect Connection Closed Error

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/connection-lifecycle

When the ConnectionClosed event is raised, you can inspect the ConnectionClosedEventArgs to determine the specific error that caused the connection termination.

```csharp
connection.ConnectionClosed += (sender, eventArgs) =>  

{  

    // reason the connection was closed    

    string reason = eventArgs.Error;  

    _logger.LogWarning(reason);  

};  
```

--------------------------------

### Override Producer Priority on Individual Message

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-priority

Send a message with a priority that overrides the default priority set on the producer. This allows for specific messages to be prioritized differently, even when sent through a producer with a default priority.

```csharp
await producer.SendAsync(new Message("foo")

{

    Priority = 0 // takes precedence over priority specified on producer level

});
```

--------------------------------

### Transactional Message Acknowledgment and Sending

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/transactions

This pattern ensures that a received message is only acknowledged after a new message, generated from its processing, is successfully sent. Both operations are committed together atomically.

```csharp
var endpoint = Endpoint.Create("localhost", 5672, "guest", "guest");  
var connectionFactory = new ConnectionFactory();  
await using var connection = await connectionFactory.CreateAsync(endpoint);  
await using var producer = await connection.CreateProducerAsync("my-address-2", RoutingType.Anycast);  
await using var consumer = await connection.CreateConsumerAsync("my-address-1", RoutingType.Anycast);  
  
var msg1 = await consumer.ReceiveAsync();  
  
await using (var transaction = new Transaction())  
{  
    // transactionally acknowledge message  
    await consumer.AcceptAsync(msg1, transaction);  
  
    var result = DoSomeProcessing(msg1);  
    var msg2 = new Message(result);  
  
    // transactionally send another message  
    await producer.SendAsync(msg2, transaction);  
  
    // commit the two operations  
    await transaction.CommitAsync();  
}  

```

--------------------------------

### Filter with AND Operator

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Use the AND operator to combine multiple conditions, ensuring all conditions must be met for a message to be received. This is useful for precise message selection.

```csharp
FilterExpression = "color = 'red' AND size = 'large'"
```

--------------------------------

### Filter by AMQPriority

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Filter messages based on their priority level (0-9). Use this to ensure only high-priority messages are received.

```csharp
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{
  
    Address = address,
  
    RoutingType = RoutingType.Anycast,
  
    FilterExpression = "AMQPriority = 9"

});  
```

```csharp
FilterExpression = "AMQPriority > 5"  // Only high-priority messages  
```

--------------------------------

### Disconnecting from ActiveMQ Artemis

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/getting-started

Call DisposeAsync on the connection object to asynchronously close the connection. Connections should be long-lived objects.

```csharp
await connection.DisposeAsync();
```

--------------------------------

### Disable Automatic Recovery

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/auto-recovery

Turn off the automatic recovery feature by setting `ConnectionFactory.AutomaticRecoveryEnabled` to `false`.

```csharp
var connectionFactory = new ConnectionFactory();
connectionFactory.AutomaticRecoveryEnabled = false;

// connection that will not recover automatically

var connection = await connectionFactory.CreateAsync(endpoint);
```

--------------------------------

### Sending an Individual Nondurable Message

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-durability

Overrides the producer's default durability setting to send a single message as nondurable. This setting takes precedence over the producer-level configuration.

```csharp
await producer.SendAsync(new Message("foo")  

{

    DurabilityMode = DurabilityMode.Nondurable // takes precedence over durability  

                                               // mode specified on the producer level  

});
```

--------------------------------

### Filter with OR Operator

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Employ the OR operator to receive messages that satisfy at least one of the specified conditions. This broadens the selection criteria.

```csharp
FilterExpression = "color = 'red' OR color = 'blue'"
```

--------------------------------

### Modify Message: Redirect to Different Consumer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-acknowledgment

Signal that the current consumer cannot handle the message but another might by calling Modify with deliveryFailed: true and undeliverableHere: true. The message is requeued, its delivery count increments, and it won't be redelivered to this consumer.

```csharp
var message = await consumer.ReceiveAsync();  

consumer.Modify(message, deliveryFailed: true, undeliverableHere: true);
```

--------------------------------

### Filter by AMQTimestamp

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Filter messages created after a specific timestamp. This is useful for processing messages sent within a certain time frame.

```csharp
var timestamp = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();  
  
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{
  
    Address = address,
  
    RoutingType = RoutingType.Anycast,
  
    FilterExpression = $"AMQTimestamp > {timestamp}"

});  
```

--------------------------------

### Modify Message: Retry on Same Consumer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-acknowledgment

Return a message to the queue for the same consumer to receive again by calling Modify with deliveryFailed: true and undeliverableHere: false. This increments the message's delivery count.

```csharp
var message = await consumer.ReceiveAsync();  

consumer.Modify(message, deliveryFailed: true, undeliverableHere: false);
```

--------------------------------

### Filter for NULL Values

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Handle messages with missing or explicitly null properties using the IS NULL operator. Conversely, use IS NOT NULL to ensure a property exists.

```csharp
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  
{
    Address = address,
    RoutingType = RoutingType.Multicast,
    FilterExpression = "optionalField IS NULL"
});
```

```csharp
FilterExpression = "requiredField IS NOT NULL"
```

--------------------------------

### Unacknowledged Messages on Consumer Close

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-acknowledgment

Messages remain unacknowledged if a consumer is closed or disposed without calling AcceptAsync, Reject, or Modify. These messages become eligible for redelivery to other consumers or will be redelivered upon reconnection for durable consumers.

```csharp
{
    await using var consumer = await connection.CreateConsumerAsync("a1", RoutingType.Anycast);

    var message = await consumer.ReceiveAsync();

    // consumer disposed here without AcceptAsync/Reject/Modify

    // message is not acknowledged and will be redelivered
}
```

--------------------------------

### Check if Connection Closed by Peer

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/connection-lifecycle

Determine if the connection was closed by the remote peer (broker) or by the client itself using the ClosedByPeer property in ConnectionClosedEventArgs.

```csharp
connection.ConnectionClosed += (sender, eventArgs) =>  

{  

    bool closedByPeer = eventArgs.ClosedByPeer;  

    if (closedByPeer)   

    {  

        _logger.LogWarning("connection was closed by the broker");  

    }  

    else  

    {  

        _logger.LogWarning("connection was closed by the client");  

    }  

};  
```

--------------------------------

### Filter by AMQExpiration

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Filter messages that expire after a specified absolute timestamp. This ensures that only non-expired messages are processed.

```csharp
var messageExpiryTime = DateTimeOffset.UtcNow.AddMinutes(10).ToUnixTimeMilliseconds();  
  
var consumer = await connection.CreateConsumerAsync(new ConsumerConfiguration  

{
  
    Address = address,
  
    RoutingType = RoutingType.Anycast,
  
    FilterExpression = $"AMQExpiration > {messageExpiryTime}"

});  
```

--------------------------------

### Modify Message: Requeue Without Incrementing Delivery Count

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-acknowledgment

Requeue a message without incrementing its delivery count by calling Modify with deliveryFailed: false and undeliverableHere: true. This is useful for handing off messages to other consumers without marking them as failed.

```csharp
var message = await consumer.ReceiveAsync();  

consumer.Modify(message, deliveryFailed: false, undeliverableHere: true);
```

--------------------------------

### Filter with IN Operator

Source: https://havret.github.io/dotnet-activemq-artemis-client/docs/message-filtering

Use the IN operator to filter messages where a property matches any value within a specified list. This simplifies filtering for multiple discrete values.

```csharp
FilterExpression = "color IN ('red', 'blue', 'green')"
```

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