rabbitmq(8)事务

男娘i 2022-05-29 14:09 163阅读 0赞

### 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 ####

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 ####

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);
    }