@Override public synchronized final String toString() {
        int accesses = hitCount + missCount;
        int hitPercent = accesses != 0 ? (100 * hitCount / accesses) : 0;
        return String.format("LruCache[maxSize=%d,hits=%d,misses=%d,hitRate=%d%%]",
                maxSize, hitCount, missCount, hitPercent);
    }
Returns a copy of the current contents of the cache, ordered from least
recently accessed to most recently accessed.
VideoSqlLite/src/main/java/com/yc/videosqllite/cache/SystemLruCache.java