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.action.hadoop;
019    
020    import java.io.IOException;
021    
022    import org.apache.hadoop.mapred.JobClient;
023    import org.apache.hadoop.mapred.JobConf;
024    import org.apache.hadoop.util.ReflectionUtils;
025    import org.apache.oozie.service.HadoopAccessorService;
026    import org.apache.oozie.service.Services;
027    
028    //TODO this class can go away once we use only 20.100+
029    public class AuthHelper {
030        private static Class<? extends AuthHelper> KLASS = null;
031    
032        @SuppressWarnings("unchecked")
033        public synchronized static AuthHelper get() {
034            if (KLASS == null) {
035                HadoopAccessorService has = Services.get().get(HadoopAccessorService.class);
036                if (has.getClass() ==  HadoopAccessorService.class) {
037                    KLASS = AuthHelper.class;
038                }
039                else {
040                    try {
041                        KLASS = (Class<? extends AuthHelper>) Class
042                                .forName("org.apache.oozie.action.hadoop.KerberosAuthHelper");
043                    }
044                    catch (ClassNotFoundException e) {
045                        throw new RuntimeException(e);
046                    }
047                }
048            }
049            return ReflectionUtils.newInstance(KLASS, null);
050        }
051    
052        public void set(JobClient jobClient, JobConf jobConf) throws IOException, InterruptedException {
053        }
054    
055    }