Human: I have a question about the Apache Hadoop Access Control Lists. How do I know if a user has access to a particular file? Assistant: 
You can use the acl_get() method of the HadoopACL class to check if a user has access to a particular file. The acl_get() method takes a path to the file and a user name as arguments. If the user has access to the file, the method returns true, otherwise it returns false.