guava 使用（com.google.common.cache）

//初始化緩存 cache = CacheBuilder.newBuilder() .maximumSize(picInfoCacheMaximumSize) .expireAfterAccess(picInfoCacheExpireAfterAccess, TimeUnit.SECONDS) .removalListener(new MyRemovalListener()) .build(); //監聽刪除 private class MyRemovalListener implements RemovalListener<String, String> { [@Override](https://my.oschina.net/u/1162528) public void onRemoval(RemovalNotification<String, String> notification) { String tips = String.format("key=%s,value=%s,reason=%s", notification.getKey(), notification.getValue(), notification.getCause()); log.info(" removalListener " + tips); } }