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 */ 018 package org.apache.oozie.service; 019 020 import java.io.IOException; 021 import java.util.concurrent.ConcurrentHashMap; 022 import java.util.concurrent.ConcurrentMap; 023 024 import org.apache.hadoop.security.UserGroupInformation; 025 026 public 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 }