code: public boolean containsKey(String field) {
  		try {
  			if (isCluster(groupName)) {
  				return getBinaryJedisClusterCommands(groupName).hexists(keyBytes, SafeEncoder.encode(field));
  			} else {
  				return getBinaryJedisCommands(groupName).hexists(keyBytes, SafeEncoder.encode(field));
  			}
  		} finally {
  			getJedisProvider(groupName).release();
  		}
  	}
docs: 查看缓存hash是否包含某个key
  
  @param field
  @return