मैसेज स्वीकृतियाँ और टिकाऊपन

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.DeliverCallback;

public class ConsumerAck {
    private final static String QUEUE_NAME = "ack_queue";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        // Declare a non-durable queue
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");

        // Set prefetch count to 1 for fair dispatch (covered in Work Queues)
        channel.basicQos(1);

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" + message + "'");
            try {
                Thread.sleep(1000); // Simulate work
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
            channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
            System.out.println(" [x] Done and Acknowledged");
        };
        
        // false means manual acknowledgement
        channel.basicConsume(QUEUE_NAME, false, deliverCallback, consumerTag -> {});

        // Producer to send a message (for testing)
        Channel producerChannel = connection.createChannel();
        producerChannel.queueDeclare(QUEUE_NAME, false, false, false, null);
        producerChannel.basicPublish("", QUEUE_NAME, null, "Hello Ack!".getBytes("UTF-8"));
        System.out.println(" [x] Sent 'Hello Ack!'");
    }
}

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.MessageProperties;

public class ProducerPersistent {
    private final static String QUEUE_NAME = "persistent_queue";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        try (Connection connection = factory.newConnection();
             Channel channel = connection.createChannel()) {
            
            // Declare a durable queue first!
            channel.queueDeclare(QUEUE_NAME, true, false, false, null);
            
            String message = "Hello Persistent Message!";
            channel.basicPublish(
                "", 
                QUEUE_NAME, 
                MessageProperties.PERSISTENT_TEXT_PLAIN, // Mark message as persistent
                message.getBytes("UTF-8")
            );
            System.out.println(" [x] Sent '" + message + "'");
        }
    }
}

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.MessageProperties;

public class ProducerDurable {
    private final static String DURABLE_QUEUE = "my_durable_queue";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        try (Connection connection = factory.newConnection();
             Channel channel = connection.createChannel()) {
            
            // Declare a durable queue (durable = true)
            channel.queueDeclare(
                DURABLE_QUEUE, 
                true,  // durable
                false, // exclusive
                false, // autoDelete
                null   // arguments
            );
            
            String message = "Hello from a durable queue!";
            channel.basicPublish(
                "", 
                DURABLE_QUEUE, 
                MessageProperties.PERSISTENT_TEXT_PLAIN, // Persistent message
                message.getBytes("UTF-8")
            );
            System.out.println(" [x] Sent '" + message + "' to durable queue.");
        }
    }
}