@Override
    public HttpCacheEntry getEntry(final String url) throws ResourceIOException {
        lock.lock();
        try {
            return entries.get(url);
        } finally {
            lock.unlock();
        }
    }
Gets an entry from the cache, if it exists

@param url
           Url that is the cache key
@return HttpCacheEntry if one exists, or null for cache miss
httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/BasicHttpCacheStorage.java