Pertukaran Surat Mati (DLX)

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

public class DLXProducerNack {
    private static final String MAIN_QUEUE_NAME = "main_nack_queue";
    private static final String DLX_EXCHANGE_NAME = "dlx_exchange";
    private static final String DLQ_QUEUE_NAME = "dlq_nack_queue";
    private static final String DLQ_ROUTING_KEY = "dlq_nack_key";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");

        try (Connection connection = factory.newConnection();
             Channel channel = connection.createChannel()) {

            // 1. Declare DLX and DLQ
            channel.exchangeDeclare(DLX_EXCHANGE_NAME, "topic", true); 
            channel.queueDeclare(DLQ_QUEUE_NAME, true, false, false, null);
            channel.queueBind(DLQ_QUEUE_NAME, DLX_EXCHANGE_NAME, DLQ_ROUTING_KEY);

            // 2. Declare main queue with DLX arguments
            Map<String, Object> args = new HashMap<>();
            args.put("x-dead-letter-exchange", DLX_EXCHANGE_NAME);
            args.put("x-dead-letter-routing-key", DLQ_ROUTING_KEY);

            channel.queueDeclare(MAIN_QUEUE_NAME, true, false, false, args);

            String message = "Message to be rejected!";
            channel.basicPublish("", MAIN_QUEUE_NAME, null, message.getBytes(StandardCharsets.UTF_8));
            System.out.println(" [x] Sent '" + message + "' to " + MAIN_QUEUE_NAME);
        }
    }
}

import com.rabbitmq.client.*;
import java.io.IOException;
import java.nio.charset.StandardCharsets;

public class DLXConsumerNack {
    private static final String MAIN_QUEUE_NAME = "main_nack_queue";
    private static final String DLQ_QUEUE_NAME = "dlq_nack_queue";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");

        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        // Consumer for the main queue, will reject messages
        System.out.println(" [*] Waiting for messages in " + MAIN_QUEUE_NAME + ".");

        DeliverCallback mainQueueDeliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), StandardCharsets.UTF_8);
            System.out.println(" [x] Received from " + MAIN_QUEUE_NAME + ": '" + message + "'");
            System.out.println(" [x] Rejecting message. It should go to DLQ.");
            channel.basicReject(delivery.getEnvelope().getDeliveryTag(), false); // Don't requeue
        };
        channel.basicConsume(MAIN_QUEUE_NAME, false, mainQueueDeliverCallback, consumerTag -> {});

        // Consumer for the dead-letter queue
        System.out.println(" [*] Waiting for messages in " + DLQ_QUEUE_NAME + " (DLQ).");

        DeliverCallback dlqDeliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), StandardCharsets.UTF_8);
            System.out.println(" [DLQ] Received dead-lettered message: '" + message + "'");
            channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
        };
        channel.basicConsume(DLQ_QUEUE_NAME, false, dlqDeliverCallback, consumerTag -> {});
    }
}

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.AMQP;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

public class DLXTTLProducer {
    private static final String MAIN_QUEUE_NAME = "main_ttl_queue";
    private static final String DLX_EXCHANGE_NAME = "dlx_exchange"; // Reuse DLX
    private static final String DLQ_QUEUE_NAME = "dlq_ttl_queue"; // Separate DLQ for TTL
    private static final String DLQ_ROUTING_KEY = "dlq_ttl_key";

    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 DLX and DLQ (if not already done)
            channel.exchangeDeclare(DLX_EXCHANGE_NAME, "topic", true);
            channel.queueDeclare(DLQ_QUEUE_NAME, true, false, false, null);
            channel.queueBind(DLQ_QUEUE_NAME, DLX_EXCHANGE_NAME, DLQ_ROUTING_KEY);

            // Declare main queue with DLX arguments and message TTL
            Map<String, Object> args = new HashMap<>();
            args.put("x-dead-letter-exchange", DLX_EXCHANGE_NAME);
            args.put("x-dead-letter-routing-key", DLQ_ROUTING_KEY);
            args.put("x-message-ttl", 5000); // Message TTL of 5 seconds

            channel.queueDeclare(MAIN_QUEUE_NAME, true, false, false, args);

            String message = "This message will expire!";
            channel.basicPublish("", MAIN_QUEUE_NAME, null, message.getBytes(StandardCharsets.UTF_8));
            System.out.println(" [x] Sent '" + message + "' to " + MAIN_QUEUE_NAME);
            System.out.println(" [x] Message has a TTL of 5 seconds. It will dead-letter if not consumed.");
        }
    }
}

import com.rabbitmq.client.*;
import java.io.IOException;
import java.nio.charset.StandardCharsets;

public class DLXTTLConsumer {
    private static final String DLQ_QUEUE_NAME = "dlq_ttl_queue";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");

        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        // Consumer for the dead-letter queue for TTL messages
        channel.queueDeclare(DLQ_QUEUE_NAME, true, false, false, null);
        System.out.println(" [*] Waiting for dead-lettered messages in " + DLQ_QUEUE_NAME + ".");
        System.out.println("     Run DLXTTLProducer first, then wait 5 seconds.");

        DeliverCallback dlqDeliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), StandardCharsets.UTF_8);
            System.out.println(" [DLQ] Received expired dead-lettered message: '" + message + "'");
            channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
        };
        channel.basicConsume(DLQ_QUEUE_NAME, false, dlqDeliverCallback, consumerTag -> {});
    }
}