001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *      http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.oozie.service;
019
020import java.io.IOException;
021import java.util.concurrent.ConcurrentHashMap;
022import java.util.concurrent.ConcurrentMap;
023
024import org.apache.hadoop.security.UserGroupInformation;
025
026public class UserGroupInformationService implements Service {
027
028    private ConcurrentMap<String, UserGroupInformation> cache = new ConcurrentHashMap<String, UserGroupInformation>();
029
030    @Override
031    public void init(Services services) throws ServiceException {
032    }
033
034    @Override
035    public void destroy() {
036        cache.clear();
037    }
038
039    @Override
040    public Class<? extends Service> getInterface() {
041        return UserGroupInformationService.class;
042    }
043
044    public UserGroupInformation getProxyUser(String user) throws IOException {
045        if (!cache.containsKey(user)) {
046            cache.putIfAbsent(user, UserGroupInformation.createProxyUser(user, UserGroupInformation.getLoginUser()));
047        }
048        return cache.get(user);
049    }
050
051}