基于 Spring Aop 环绕通知实现 Redis 缓存双删功能(示例代码)

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基于 spring aop 常规应用场景多是用于日志记录以及实现 redis 分布式锁，在 github 中也有项目是把它拿来当作缓存的异常捕捉。从而避免影响实际业务的开发；在某天，笔者有个业务开发是给某个服务模块增加 redis 缓存。增加缓存就会涉及 redis 删除。所以笔者就在思考是不是可以用环绕通知的方式来进行实现

代码实现

结构示意图：

自定义注解 RedisDelByDbUpdate

@Repeatable 表示允许在同一个地方上使用相同的注解，没有该注解时贴相同注解会报错

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Repeatable(RedisDelByDbUpdateList.class)
public @interface RedisDelByDbUpdate {
    /**
     * 具体操作得缓存前缀
     */
    String redisPrefix() default "";
 
    /**
     * 具体的缓存名称，为空则删除 redisPrefix 下的所有缓存
     */
    String fieldName() default "";
}

自定义注解 RedisDelByUpdateList

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RedisDelByDbUpdateList {
    
    RedisDelByDbUpdate[] value();
}

具体实现 redis 双删逻辑

@Aspect
@Component
@Slf4j
public class RedisDelAspect_bak {
    //环绕增强
    @Autowired
    private RedisUtil redis;
 
    @Pointcut("@annotation(com.cili.baseserver.aop.annotation.RedisDelByDbUpdate) " +
            "|| @annotation(com.cili.baseserver.aop.annotation.RedisDelByDbUpdateList)")
    public void pointCut() {
 
    }
 
    // 线程池定长设置：最佳线程数目 = ((线程等待时间+线程CPU时间)/线程CPU时间 )* CPU数目
    ScheduledExecutorService threadPool = Executors.newScheduledThreadPool(26);
 
    /**
     * 环绕增强
     *
     * @param point
     * @return
     * @throws Throwable
     */
    @Around("pointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Method method = signature.getMethod();
 
        RedisDelByDbUpdate redisDelByDbUpdate = method.getAnnotation(RedisDelByDbUpdate.class);
        if (redisDelByDbUpdate != null) {
            return singleRedisDel(redisDelByDbUpdate, point);
        }
 
        RedisDelByDbUpdateList updateList = method.getAnnotation(RedisDelByDbUpdateList.class);
        return arraysRedisDel(updateList, point);
    }
 
    private Object singleRedisDel(RedisDelByDbUpdate redisDelByDbUpdate, ProceedingJoinPoint point) throws Throwable {
        return handle(redisDelByDbUpdate, point, new IObjectCallback() {
            public 
    
      T callback() throws Throwable { return (T) point.proceed(); } }); } private Object arraysRedisDel(RedisDelByDbUpdateList updateList, ProceedingJoinPoint point) throws Throwable { RedisDelByDbUpdate[] redisDelByDbUpdates = updateList.value(); for (int i = 0; i () { public 
     
       T callback() throws Throwable { return flag ? (T) point.proceed() : null; } }); if (flag) return obj; } return null; } private Object handle(RedisDelByDbUpdate redisDelByDbUpdate, ProceedingJoinPoint point, IObjectCallback
       object) throws Throwable { String prefix = redisDelByDbUpdate.redisPrefix(); String fieldName = redisDelByDbUpdate.fieldName(); if (ValueUtil.isEmpty(prefix)) { log.info("redis缓存前缀不能为空"); throw new BizException(BaseResponseCode.SYSTEM_BUSY); } Object arg = point.getArgs()[0]; String key = ""; String[] redisKeys = null; if (ValueUtil.isNotEmpty(fieldName)) { if (arg instanceof ArrayList) { redisKeys = ((ArrayList>) arg).stream().map(item -> prefix + item).toArray(String[]::new); } else { Map
       
         map = (Map
        
         ) JsonUtil.toMap(JsonUtil.toJSON(point.getArgs()[0])); key = map.get(fieldName).toString(); } } else { // 获取所有该前缀下缓存 Set
         
           keys = redis.keys(prefix + "*"); redisKeys = keys.stream().toArray(String[]::new); } // 删除缓存 String redisKey = prefix + key; delete(redisKey, redisKeys); Object result = object.callback(); // 延时删除 try { String[] finalRedisKeys = redisKeys; threadPool.schedule(new Runnable() { @Override public void run() { delete(redisKey, finalRedisKeys); } }, 500, TimeUnit.MILLISECONDS); } catch (Exception e) { log.error("线程池延时删除缓存失败:{}", redisKey); } return result; } private void delete(String redisKey, String[] redisKeys) { if (ValueUtil.isEmpty(redisKeys)) { redis.delete(redisKey); return; } redis.del(redisKeys); } }
         
        
       
     
    

注解使用示例

public class Test {
    @Override
    @RedisDelByDbUpdate(redisPrefix = RedisConstant.BANNER, fieldName = "ids")
    @RedisDelByDbUpdate(redisPrefix = RedisConstant.BANNER_LIST)
    public void batchDeleted(List
   
     ids) throws BizException {
        if (CollectionUtils.isEmpty(ids)) {
            log.info("banner ID 不能为空");
            throw new BizException(BaseResponseCode.PARAM_IS_NOT_NULL);
        }
        try {
            bannerMapper.batchDeleted(ids);
        } catch (Exception e) {
            log.error("==>批量删除Banner错误:{}