How is the Consumer interface in Java implemented and how does it function for message processing?

In C#, the Consumer interface as such does not exist, but the concept of message processing is often implemented through delegates, interfaces with a processing method, or through built-in types such as Action<T>.

When it comes to message processing, a common approach is to create an interface with a method that accepts a message and performs the necessary actions:

public interface IConsumer<T>
{
    void Consume(T message);
}

public class MessageConsumer : IConsumer<string>
{
    public void Consume(string message)
    {
        Console.WriteLine($"Received message: {message}");
        // message processing
    }
}

Functionality:

• An object implementing IConsumer<T> receives a message through the Consume method.
• Inside the method, the processing logic is implemented — for example, writing to a database, calling other services, etc.

In some libraries (for example, for working with message queues), Consumer is a component that subscribes to a message stream and calls the processing method upon receiving new data.