Redis自动过期机制

「爱情、让人受尽委屈。」 2023-06-15 09:50 13阅读 0赞

实现需求：处理订单过期自动取消，比如下单30分钟未支付自动更改订单状态

实现方案：

1.  使用Redis Key自动过期触发事件通知
2.  使用定时任务30分钟后检查
3.  按照每分钟轮训检查

CREATE TABLE `order_number` (
      `id` int(11) NOT NULL AUTO_INCREMENT,
      `order_name` varchar(255) DEFAULT NULL,
      `order_status` int(11) DEFAULT NULL,
      `order_token` varchar(255) DEFAULT NULL,
      `order_id` varchar(255) DEFAULT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB AUTO_INCREMENT=20 DEFAULT CHARSET=utf8;

#### 一、使用Redis Key自动过期机制 ####

当我们的key失效时，可以执行我们的客户端回调监听的方法。

需要在Redis中配置：notify-keyspace-events Ex

#### 二、SpringBoot整合key失效监听 ####

@Configuration
    public class RedisListenerConfig { 
        @Bean
        RedisMessageListenerContainer container(RedisConnectionFactory connectionFactory) { 
            RedisMessageListenerContainer container = new RedisMessageListenerContainer();
            container.setConnectionFactory(connectionFactory);
            return container;
        }
    }

@Component
    public class RedisKeyExpirationListener extends KeyExpirationEventMessageListener { 
        public RedisKeyExpirationListener(RedisMessageListenerContainer listenerContainer) { 
            super(listenerContainer);
        }
    
        /** * 待支付 */
        private static final Integer ORDER_STAYPAY = 0;
        /** * 失效 */
        private static final Integer ORDER_INVALID = 2;
        @Autowired
        private OrderMapper orderMapper;
    
        /** * Redis失效事件 key * * @param message * @param pattern */
        @Override
        public void onMessage(Message message, byte[] pattern) { 
            String expiraKey = message.toString();
            // 根据key查询 value 如果还还是为待支付状态 将订单改为已经超时~~
            OrderEntity orderNumber = orderMapper.getOrderNumber(expiraKey);
            System.out.println(expiraKey);
            if (orderNumber == null) { 
                return;
            }
            if (orderNumber.getOrderStatus().equals(ORDER_STAYPAY)) { 
                // 将订单状态改为已经失效
                orderMapper.updateOrderStatus(expiraKey, ORDER_INVALID);
            }
        }
    }

@RestController
    public class OrderController { 
        @Autowired
        private OrderMapper orderMapper;
        @Autowired
        private RedisUtils redisUtils;
    
        @RequestMapping("/saveOrder")
        public String saveOrder() { 
            // 1.生成token
            String orderToken = UUID.randomUUID().toString();
            String orderId = System.currentTimeMillis() + "";
            //2. 将该token存放到redis中
            redisUtils.setString(orderToken, orderId, 5L);
            OrderEntity orderEntity = new OrderEntity(null, "会员", orderId, orderToken);
            int result = orderMapper.insertOrder(orderEntity);
            return result > 0 ? "success" : "fail";
        }
    }

@Data
    public class OrderEntity { 
        private Long id;
        private String orderName;
        /** * 0 待支付 1 已经支付 */
        private Integer orderStatus;
    
        private String orderToken;
        private String orderId;
    
        public OrderEntity(Long id, String orderName, String orderId, String orderToken) { 
            this.id = id;
            this.orderName = orderName;
            this.orderId = orderId;
            this.orderToken = orderToken;
        }
    }

public interface OrderMapper { 
    
        @Insert("insert into order_number values (null,#{orderName},0,#{orderToken},#{orderId})")
        int insertOrder(OrderEntity OrderEntity);
    
    
        @Select("SELECT ID AS ID ,order_name AS ORDERNAME ,order_status AS orderstatus,order_token as ordertoken,order_id as orderid FROM order_number\n" +
                "where order_token=#{orderToken};")
        OrderEntity getOrderNumber(String orderToken);
    
        @Update("\n" +
                "\n" +
                "update order_number set order_status=#{orderStatus} where order_token=#{orderToken};")
        int updateOrderStatus(String orderToken, Integer orderStatus);
    }