org.springframework.data.hadoop.util.PermissionUtils.java Source code

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Here is the source code for org.springframework.data.hadoop.util.PermissionUtils.java

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/*
 * Copyright 2011-2013 the original author or authors.
 * 
 * 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.springframework.data.hadoop.util;

import java.lang.reflect.Field;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.mapreduce.JobSubmissionFiles;
import org.springframework.util.ReflectionUtils;

/**
 * Simple utility class that fixes the File permission problem on 
 * Windows. A temporary work-around until Hadoop fixes this issue out of the box.
 * Needs to be called, once per class-loader, before submitting a job to Hadoop.
 * 
 * @author Costin Leau
 * @author Thomas Risberg
 */
public class PermissionUtils {

    private static final Log log = LogFactory.getLog(PermissionUtils.class);

    private static Class<?> trackerDistributedCacheManagerClass;

    static {
        if (System.getProperty("os.name").toLowerCase().startsWith("win")) {
            try {
                trackerDistributedCacheManagerClass = Class
                        .forName("org.apache.hadoop.filecache.TrackerDistributedCacheManager");
            } catch (ClassNotFoundException e) {
                trackerDistributedCacheManagerClass = null;
                log.warn("Unable to provide Windows jar permission fix: " + e.getMessage());
                e.printStackTrace();
            }
        }
    }

    public static void hackHadoopStagingOnWin() {
        // do the assignment only on Windows systems
        if (System.getProperty("os.name").toLowerCase().startsWith("win")) {
            // 0655 = -rwxr-xr-x
            JobSubmissionFiles.JOB_DIR_PERMISSION.fromShort((short) 0650);
            JobSubmissionFiles.JOB_FILE_PERMISSION.fromShort((short) 0650);

            if (trackerDistributedCacheManagerClass != null) {
                // handle jar permissions as well
                Field field = ReflectionUtils.findField(trackerDistributedCacheManagerClass,
                        "PUBLIC_CACHE_OBJECT_PERM");
                ReflectionUtils.makeAccessible(field);
                FsPermission perm = (FsPermission) ReflectionUtils.getField(field, null);
                perm.fromShort((short) 0650);
            }
        }
    }
}