rabbitmq通过订阅接受消息java代码案例

### RabbitMQ Java Example Code for Subscribing and Receiving Messages To subscribe and receive messages from RabbitMQ using Java, one can utilize the `com.rabbitmq.client` library which provides necessary classes such as `Channel`, `Connection`, etc., to interact with RabbitMQ server. Below is an example of how this could be implemented: ```java import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; public class ReceiveMessages { private final static String QUEUE_NAME = "test_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()) { channel.queueDeclare(QUEUE_NAME, false, false, false, null); System.out.println("[*] Waiting for messages. To exit press CTRL+C"); DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println("[x] Received '" + message + "'"); // Acknowledge receipt of the message. channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false); }; boolean autoAck = false; // Manual acknowledgment mode enabled by setting this flag to false channel.basicConsume(QUEUE_NAME, autoAck, deliverCallback, consumerTag -> {}); } } } ``` This program sets up a queue named `"test_queue"` on localhost RabbitMQ instance[^1]. It listens continuously until interrupted externally while printing out any received messages along with acknowledging them after processing has completed successfully.