使用场景
1、下单成功，30分钟未支付。支付超时，自动取消订单
2、订单签收，签收后7天未进行评价。订单超时未评价，系统默认好评
3、下单成功，商家5分钟未接单，订单取消
4、配送超时，推送短信提醒
......
对于延时比较长的场景、实时性不高的场景，我们可以采用任务调度的方式定时轮询处理。如：xxl-job
今天我们采用一种比较简单、轻量级的方式，使用 Redis 的延迟队列来进行处理。当然有更好的解决方案，可根据公司的技术选型和业务体系选择最优方案。如：使用消息中间件Kafka、RabbitMQ 的延迟队列
先不讨论其实现原理，直接实战上代码先实现基于 Redis 的延迟队列
1、引入 Redisson 依赖
-
<dependency>
-
<groupId>org.redisson
</groupId>
-
<artifactId>redisson-spring-boot-starter
</artifactId>
-
<version>3.10.5
</version>
-
</dependency>
2、Nacos 配置 Redis 连接
-
spring:
-
redis:
-
host:
127.0
.0
.1
-
port:
6379
-
password:
123456
-
database:
12
-
timeout:
3000
3、创建 RedissonConfig 配置
-
/**
-
* Created by LPB on 2020/04/20.
-
*/
-
@Configuration
-
public
class RedissonConfig {
-
-
@Value("${spring.redis.host}")
-
private String host;
-
@Value("${spring.redis.port}")
-
private int port;
-
@Value("${spring.redis.database}")
-
private int database;
-
@Value("${spring.redis.password}")
-
private String password;
-
-
@Bean
-
public RedissonClient redissonClient() {
-
Config config = new Config();
-
config.useSingleServer()
-
.setAddress(
"redis://" + host +
":" + port)
-
.setDatabase(database)
-
.setPassword(password);
-
return Redisson.create(config);
-
}
-
-
}
4、封装 Redis 延迟队列工具类
-
/**
-
* redis延迟队列工具
-
* Created by LPB on 2021/04/20.
-
*/
-
@Slf4j
-
@Component
-
public
class RedisDelayQueueUtil {
-
-
@Autowired
-
private RedissonClient redissonClient;
-
-
/**
-
* 添加延迟队列
-
* @param value 队列值
-
* @param delay 延迟时间
-
* @param timeUnit 时间单位
-
* @param queueCode 队列键
-
* @param <T>
-
*/
-
public <T>
void addDelayQueue(T value, long delay, TimeUnit timeUnit,
String queueCode){
-
try {
-
RBlockingDeque<
Object> blockingDeque = redissonClient.getBlockingDeque(queueCode);
-
RDelayedQueue<
Object> delayedQueue = redissonClient.getDelayedQueue(blockingDeque);
-
delayedQueue.offer(value, delay, timeUnit);
-
log.info(
"(添加延时队列成功) 队列键：{}，队列值：{}，延迟时间：{}", queueCode, value, timeUnit.toSeconds(delay) +
"秒");
-
}
catch (
Exception e) {
-
log.
error(
"(添加延时队列失败) {}", e.getMessage());
-
throw
new
RuntimeException(
"(添加延时队列失败)");
-
}
-
}
-
-
/**
-
* 获取延迟队列
-
* @param queueCode
-
* @param <T>
-
* @return
-
* @throws InterruptedException
-
*/
-
public <T> T getDelayQueue(
String queueCode) throws InterruptedException {
-
RBlockingDeque<Map> blockingDeque = redissonClient.getBlockingDeque(queueCode);
-
T value = (T) blockingDeque.take();
-
return value;
-
}
-
}
5、创建延迟队列业务枚举
-
/**
-
* 延迟队列业务枚举
-
* Created by LPB on 2021/04/20.
-
*/
-
@Getter
-
@NoArgsConstructor
-
@AllArgsConstructor
-
public enum RedisDelayQueueEnum {
-
-
ORDER_PAYMENT_TIMEOUT(
"ORDER_PAYMENT_TIMEOUT",
"订单支付超时，自动取消订单",
"orderPaymentTimeout"),
-
ORDER_TIMEOUT_NOT_EVALUATED(
"ORDER_TIMEOUT_NOT_EVALUATED",
"订单超时未评价，系统默认好评",
"orderTimeoutNotEvaluated");
-
-
/**
-
* 延迟队列 Redis Key
-
*/
-
private
String
code;
-
-
/**
-
* 中文描述
-
*/
-
private
String
name;
-
-
/**
-
* 延迟队列具体业务实现的 Bean
-
* 可通过 Spring 的上下文获取
-
*/
-
private
String
beanId;
-
-
}
6、定义延迟队列执行器
-
/**
-
* 延迟队列执行器
-
* Created by LPB on 2021/04/20.
-
*/
-
public
interface
RedisDelayQueueHandle<
T> {
-
-
void execute(T t);
-
-
}
7、创建枚举中定义的Bean，并实现延迟队列执行器
- OrderPaymentTimeout：订单支付超时延迟队列处理类
-
/**
-
* 订单支付超时处理类
-
* Created by LPB on 2021/04/20.
-
*/
-
@Component
-
@Slf4j
-
public class OrderPaymentTimeout implements RedisDelayQueueHandle<Map> {
-
@Override
-
public void execute(Map map) {
-
log
.info(
"(收到订单支付超时延迟消息) {}", map);
-
// TODO 订单支付超时，自动取消订单处理业务...
-
-
}
-
}
- OrderTimeoutNotEvaluated：订单超时未评价延迟队列处理类
-
/**
-
* 订单超时未评价处理类
-
* Created by LPB on 2021/04/20.
-
*/
-
@Component
-
@Slf4j
-
public class OrderTimeoutNotEvaluated implements RedisDelayQueueHandle<Map> {
-
@Override
-
public void execute(Map map) {
-
log
.info(
"(收到订单超时未评价延迟消息) {}", map);
-
// TODO 订单超时未评价，系统默认好评处理业务...
-
-
}
-
}
8、创建延迟队列消费线程，项目启动完成后开启
-
/**
-
* 启动延迟队列
-
* Created by LPB on 2021/04/20.
-
*/
-
@Slf4j
-
@Component
-
public
class RedisDelayQueueRunner implements CommandLineRunner {
-
-
@Autowired
-
private RedisDelayQueueUtil redisDelayQueueUtil;
-
-
@Override
-
public
void run(String... args) {
-
new Thread(() -> {
-
while (
true){
-
try {
-
RedisDelayQueueEnum[] queueEnums = RedisDelayQueueEnum.values();
-
for (RedisDelayQueueEnum
queueEnum : queueEnums) {
-
Object value = redisDelayQueueUtil.getDelayQueue(queueEnum.getCode());
-
if (value !=
null) {
-
RedisDelayQueueHandle redisDelayQueueHandle = SpringUtil.getBean(queueEnum.getBeanId());
-
redisDelayQueueHandle.execute(value);
-
}
-
}
-
}
catch (InterruptedException e) {
-
log.error(
"(Redis延迟队列异常中断) {}", e.getMessage());
-
}
-
}
-
}).start();
-
log.info(
"(Redis延迟队列启动成功)");
-
}
-
}
以上步骤，Redis 延迟队列核心代码已经完成，下面我们写一个测试接口，用 PostMan 模拟测试一下
9、创建一个测试接口，模拟添加延迟队列
-
/**
-
* 延迟队列测试
-
* Created by LPB on 2020/04/20.
-
*/
-
@RestController
-
public
class RedisDelayQueueController {
-
-
@Autowired
-
private RedisDelayQueueUtil redisDelayQueueUtil;
-
-
@PostMapping(
"/addQueue")
-
public
void addQueue() {
-
Map<
String,
String> map1 =
new HashMap<>();
-
map1.put(
"orderId",
"100");
-
map1.put(
"remark",
"订单支付超时，自动取消订单");
-
-
Map<
String,
String> map2 =
new HashMap<>();
-
map2.put(
"orderId",
"200");
-
map2.put(
"remark",
"订单超时未评价，系统默认好评");
-
-
// 添加订单支付超时，自动取消订单延迟队列。为了测试效果，延迟10秒钟
-
redisDelayQueueUtil.addDelayQueue(map1,
10, TimeUnit.SECONDS, RedisDelayQueueEnum.ORDER_PAYMENT_TIMEOUT.getCode());
-
-
// 订单超时未评价，系统默认好评。为了测试效果，延迟20秒钟
-
redisDelayQueueUtil.addDelayQueue(map2,
20, TimeUnit.SECONDS, RedisDelayQueueEnum.ORDER_TIMEOUT_NOT_EVALUATED.getCode());
-
}
-
-
}
10、启动 SpringBoot 项目，用 PostMan 调用接口添加延迟队列
- 通过 Redis 客户端可看到两个延迟队列已添加成功
- 查看 IDEA 控制台日志可看到延迟队列已消费成功
转载：https://blog.csdn.net/qq_40087415/article/details/115940092
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