@Override
        public V get(K key) throws CacheException {
            try {
                LOGGER.trace("Getting object from cache [{}] for key [{}]", cache.getName(), key);
                if (key == null) {
                    return null;
                } else {
                    V element = cache.get(key);
                    if (element == null) {
                        LOGGER.trace("Element for [{}] is null.", key);
                        return null;
                    } else {
                        return element;
                    }
                }
            } catch (Throwable t) {
                throw new CacheException(t);
            }
        }
Gets a value of an element which matches the given key.

@param key the key of the element to return.
@return The value placed into the cache with an earlier put, or null if not found or expired
support/jcache/src/main/java/org/apache/shiro/cache/jcache/JCacheManager.java