redis用list做訊息佇列的實現範例

2022-02-18 13:03:23

生產訊息服務

@Service
public class RedisService {
    @Autowired
    private RedisTemplate<String, String> redisTemplate;


    public Object publish() {
        OrderDTO dto = new OrderDTO();
        dto.setId(1);
        dto.setCreateTime(new Date());
        dto.setMoney("12.34");
        dto.setOrderNo("orderNo1");
        String s = JSON.toJSONString(dto);

        ListOperations<String, String> listOperations = redisTemplate.opsForList();
        //leftPush和rightPop對應，左邊入隊，右邊出隊
        listOperations.leftPush(RedisConstant.MQ_LIST, s);

        //因為出隊是阻塞讀取的，所以上一步入隊後，資料立刻就被驅走了，下一步size=0
        Long size = listOperations.size(RedisConstant.MQ_LIST);
        List<String> list = new ArrayList<>();
        if (size != null && size > 0) {
             list = listOperations.range(RedisConstant.MQ_LIST, 0, size - 1);
        }
        return list;

    }
}

測試

@RestController
@RequestMapping("redisList")
public class RedisListController {

    @Autowired
    private RedisService redisService;

    @GetMapping("publish")
    public Object publish() {
        return redisService.publish();
    }
}

消費訊息服務，定時任務

@Component
public class RedisConsumeTask {
    @Autowired
    private RedisService redisService;

    @TaskLock(RedisConstant.CONSUME_REDIS_LIST)
    @Scheduled(cron = "0/10 * * * * ?")
    public void consumeMqList() {
        redisService.consumeMqList();
    }
}

@Service
@Slf4j
public class RedisService {

    @Autowired
    private RedisTemplate<String, String> redisTemplate;

    public void consumeMqList() {
        ListOperations<String, String> listOperations = redisTemplate.opsForList();
        //0時間，表示阻塞永久
        //待機一小時後，再次發訊息，消費不了了，阻塞有問題啊。還得輪尋啊
        //String s = listOperations.rightPop(RedisConstant.MQ_LIST, 0L, TimeUnit.SECONDS);
        String s = listOperations.rightPop(RedisConstant.MQ_LIST);
        if (s == null) {
            return;
        }

        log.info("{} = {}", RedisConstant.MQ_LIST, s);

        OrderDTO dto = JSON.parseObject(s, OrderDTO.class);
        log.info("dto = {}", dto);
    }
}

紀錄檔

@Component
@Aspect
public class TaskLockAop {

    @Autowired
    private RedisLockRegistry redisLockRegistry;

    @Around("execution(@TaskLock * * (..))")
    public Object taskAround(ProceedingJoinPoint pjp) throws Throwable {

        TaskLock taskAnnotation = ((MethodSignature)pjp.getSignature()).getMethod().getAnnotation(TaskLock.class);

        String lockKey = taskAnnotation.value();
        Lock lock = redisLockRegistry.obtain(lockKey);
        try {
            lock.tryLock(30L, TimeUnit.SECONDS);
            System.out.println("任務開始, " + lockKey + ", " + new Date());

            return pjp.proceed();

        } finally {
            lock.unlock();
            System.out.println("任務結束, " + lockKey + ", " + new Date());
        }
    }
}