com.ikanow.aleph2.core.shared.utils.DirUtils.java Source code

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Here is the source code for com.ikanow.aleph2.core.shared.utils.DirUtils.java

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/*******************************************************************************
 * Copyright 2015, The IKANOW Open Source Project.
 *
 * 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 com.ikanow.aleph2.core.shared.utils;

import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.StandardCharsets;
import java.util.EnumSet;
import java.util.List;

import org.apache.hadoop.fs.CreateFlag;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileContext;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

/** 
 * Utility class working on FileContext.
 * @author jfreydank
 *
 */
public class DirUtils {
    private static final Logger logger = LogManager.getLogger(DirUtils.class);

    /** This method returns the path to the first subdirectory matching the subDirectoryName parameter or null if not found.
    * @param fileContext
    * @param start
    * @param subDirectoryName
    * @return
    */
    public static Path findOneSubdirectory(FileContext fileContext, Path start, String subDirectoryName) {
        Path p = null;
        try {
            logger.debug("findOneSubdirectory :" + start.toString());
            FileStatus[] statuss = fileContext.util().listStatus(start);
            for (int i = 0; i < statuss.length; i++) {
                FileStatus dir = statuss[i];
                logger.debug("FileStatus:" + statuss[i].getPath().toString());
                if (dir.isDirectory()) {
                    if (dir.getPath().getName().contains(subDirectoryName)) {
                        logger.debug("findOneSubdirectory match:" + dir.getPath().getName());
                        return dir.getPath();
                    } else {
                        p = findOneSubdirectory(fileContext, dir.getPath(), subDirectoryName);
                        if (p != null) {
                            return p;
                        }
                    }
                }
            }

        } catch (Exception e) {
            logger.error("findOneSubdirectory Caught Exception", e);
        }

        return p;
    }

    public static final FsPermission DEFAULT_DIR_PERMS = FsPermission.valueOf("drwxrwxrwx");

    /** Creates a directory in the storage servce
     * @param fileContext
     * @param pathString
     */
    public static void createDirectory(FileContext fileContext, String pathString) {
        if (fileContext != null && pathString != null) {
            try {
                Path dir = new Path(pathString);
                if (!fileContext.util().exists(dir)) {
                    fileContext.mkdir(dir, DEFAULT_DIR_PERMS, true); //(note perm is & with umask)
                    try {
                        fileContext.setPermission(dir, DEFAULT_DIR_PERMS);
                    } catch (Exception e) {
                    } // (not supported in all FS)
                }
            } catch (Exception e) {
                logger.error("createFolderStructure Caught Exception", e);
            }
        }

    }

    /**
     * @param allPaths
     * @param fileContext
     * @param start
     * @param subDirectoryName
     * @param includeMatched
     */
    public static void findAllSubdirectories(List<Path> allPaths, FileContext fileContext, Path start,
            String subDirectoryName, boolean includeMatched) {
        try {
            logger.debug("findAllSubdirectories :" + start.toString());
            FileStatus[] statuss = fileContext.util().listStatus(start);
            for (int i = 0; i < statuss.length; i++) {
                FileStatus dir = statuss[i];
                logger.debug("FileStatus:" + statuss[i].getPath().toString());
                if (dir.isDirectory()) {
                    if (dir.getPath().getName().contains(subDirectoryName)) {
                        logger.debug("findOneSubdirectory match:" + dir.getPath().getName());
                        if (includeMatched) {
                            allPaths.add(dir.getPath());
                        } else {
                            allPaths.add(dir.getPath().getParent());
                        }
                    } else {
                        findAllSubdirectories(allPaths, fileContext, dir.getPath(), subDirectoryName,
                                includeMatched);
                    }
                }
            }

        } catch (Exception e) {
            logger.error("findAllSubdirectories Caught Exception", e);
        }
    }

    /** Creates a text file  in the storage service 
     * @param fileContext
     * @param fileNameString
     * @param sb
     */
    public static void createUTF8File(FileContext fileContext, String fileNameString, StringBuffer sb) {
        if (fileContext != null && fileNameString != null) {
            try {
                Path f = new Path(fileNameString);
                FSDataOutputStream out = fileContext.create(f, EnumSet.of(CreateFlag.CREATE, CreateFlag.OVERWRITE));
                //Read from input stream and write to output stream until EOF.
                Charset charset = StandardCharsets.UTF_8;
                CharsetEncoder encoder = charset.newEncoder();

                // No allocation performed, just wraps the StringBuilder.
                CharBuffer buffer = CharBuffer.wrap(sb.toString());

                byte[] bytes = encoder.encode(buffer).array();
                out.write(bytes);
                out.close();

            } catch (Exception e) {
                logger.error("createFolderStructure Caught Exception", e);
            }
        }

    }

}