马老师P9亲授技术人员的产品普及课

private void init() {        errorExceptionCache = Caffeine.newBuilder().expireAfterWrite(3, TimeUnit.SECONDS)                .removalListener((RemovalListener<Integer, AtomicInteger>)(key, value, cause) -> {                    System.out.println("in removal listener," + cause + ":" + key + "->" + value);                    if(cause == RemovalCause.EXPIRED) {