001    /**
002     * Copyright (c) 2010 Yahoo! Inc. All rights reserved.
003     * Licensed under the Apache License, Version 2.0 (the "License");
004     * you may not use this file except in compliance with the License.
005     * You may obtain a copy of the License at
006     *
007     *   http://www.apache.org/licenses/LICENSE-2.0
008     *
009     *  Unless required by applicable law or agreed to in writing, software
010     *  distributed under the License is distributed on an "AS IS" BASIS,
011     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012     *  See the License for the specific language governing permissions and
013     *  limitations under the License. See accompanying LICENSE file.
014     */
015    package org.apache.oozie.action.hadoop;
016    
017    import java.io.IOException;
018    
019    import org.apache.hadoop.mapred.JobClient;
020    import org.apache.hadoop.mapred.JobConf;
021    import org.apache.hadoop.util.ReflectionUtils;
022    import org.apache.oozie.service.HadoopAccessorService;
023    import org.apache.oozie.service.Services;
024    
025    //TODO this class can go away once we use only 20.100+
026    public class AuthHelper {
027        private static Class<? extends AuthHelper> KLASS = null;
028    
029        @SuppressWarnings("unchecked")
030        public synchronized static AuthHelper get() {
031            if (KLASS == null) {
032                HadoopAccessorService has = Services.get().get(HadoopAccessorService.class);
033                if (has.getClass() ==  HadoopAccessorService.class) {
034                    KLASS = AuthHelper.class;
035                }
036                else {
037                    try {
038                        KLASS = (Class<? extends AuthHelper>) Class
039                                .forName("org.apache.oozie.action.hadoop.KerberosAuthHelper");
040                    }
041                    catch (ClassNotFoundException e) {
042                        throw new RuntimeException(e);
043                    }
044                }
045            }
046            return ReflectionUtils.newInstance(KLASS, null);
047        }
048    
049        public void set(JobClient jobClient, JobConf jobConf) throws IOException, InterruptedException {
050        }
051    
052    }