| /* |
| * Copyright 2015 Apache Software Foundation. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.security; |
| |
| import java.util.Collections; |
| import java.util.List; |
| |
| /** |
| * This class provides groups mapping for {@link UserGroupInformation} when the |
| * user group information will not be used. |
| */ |
| public class NullGroupsMapping implements GroupMappingServiceProvider { |
| /** |
| * Nothing is returned, so nothing is cached. |
| * @param groups ignored |
| */ |
| @Override |
| public void cacheGroupsAdd(List<String> groups) { |
| } |
| |
| /** |
| * Returns an empty list. |
| * @param user ignored |
| * @return an empty list |
| */ |
| @Override |
| public List<String> getGroups(String user) { |
| return Collections.emptyList(); |
| } |
| |
| /** |
| * Nothing is returned, so nothing is cached. |
| */ |
| @Override |
| public void cacheGroupsRefresh() { |
| } |
| } |