public V remove(K key) {
		writeLock.lock();
		try {
			return cache.remove(key);
		} finally {
			writeLock.unlock();
		}
	}
public V remove ( K key ) { writeLock . lock ( ) ; try { return cache . remove ( key ) ; } finally { writeLock . unlock ( ) ; } }
移除缓存

@param key 键
@return 移除的值