rabbitmq(8)事务

rabbitmq

1、概述

rabbitmq的事务机制可以保证生产者发送的消息成功传递到broker。如果在事务提交前由于本地或broker的问题发生异常，则可以回滚事务。

2、代码

2.1、生产者

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private final static String QUEUE_NAME = "hello";

@Test
public void testSend() throws Exception {
	ConnectionFactory factory = new ConnectionFactory();
    factory.setHost("192.168.1.7");
    factory.setUsername("root");
    factory.setPassword("123456");
    
	Connection connection = factory.newConnection();
	Channel channel = connection.createChannel();
	
	channel.queueDeclare(QUEUE_NAME, true, false, false, null);
	
	/**
	 * 事务模式吞吐量低
	 */
	try {
		// 开启事务
		channel.txSelect();
		
		String message = "Hello World!";
		channel.basicPublish("", QUEUE_NAME, null, message.getBytes());
		System.out.println(" [x] Sent '" + message + "'");
		
		/**
		 * 如果在提交事务前发生异常,则通过回滚事务,消费者将不会接收到该消息
		 */
		
		// 提交事务
		channel.txCommit();
	} catch (Exception e) {
		// 回滚事务
		channel.txRollback();
		e.printStackTrace();
	}
	
	channel.close();
	connection.close();
}

2.2、消费者

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private final static String QUEUE_NAME = "hello";

public static void main(String[] args) throws Exception {
	ConnectionFactory factory = new ConnectionFactory();
    factory.setHost("192.168.1.7");
    factory.setUsername("root");
    factory.setPassword("123456");
    
	Connection connection = factory.newConnection();
	Channel channel = connection.createChannel();

	channel.queueDeclare(QUEUE_NAME, true, false, false, null);
	System.out.println(" [*] Waiting for messages.");
	Consumer consumer = new DefaultConsumer(channel) {
		@Override
		public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties,
				byte[] body) throws IOException {
			String message = new String(body, "UTF-8");
			System.out.println(" [x] Received '" + message + "'");
		}
	};
	channel.basicConsume(QUEUE_NAME, true, consumer);
}
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