gobblin.util.FileListUtils.java Source code

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Here is the source code for gobblin.util.FileListUtils.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 gobblin.util;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Comparator;
import java.util.List;

import org.apache.commons.lang.ArrayUtils;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathFilter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.Lists;
import com.google.common.primitives.Longs;

/**
 * Utility class for listing files on a {@link FileSystem}.
 *
 * @see FileSystem
 */
public class FileListUtils {
    private static final Logger LOG = LoggerFactory.getLogger(FileListUtils.class);

    public static final Comparator<FileStatus> LATEST_MOD_TIME_ORDER = new Comparator<FileStatus>() {
        @Override
        public int compare(FileStatus file1, FileStatus file2) {
            return Longs.compare(Long.valueOf(file2.getModificationTime()),
                    Long.valueOf(file1.getModificationTime()));
        }
    };

    public static final PathFilter NO_OP_PATH_FILTER = new PathFilter() {
        @Override
        public boolean accept(Path path) {
            return true;
        }
    };

    public static List<FileStatus> listFilesRecursively(FileSystem fs, Path path) throws IOException {
        return listFilesRecursively(fs, path, NO_OP_PATH_FILTER);
    }

    public static List<FileStatus> listFilesRecursively(FileSystem fs, Iterable<Path> paths) throws IOException {
        List<FileStatus> results = Lists.newArrayList();
        for (Path path : paths) {
            results.addAll(listFilesRecursively(fs, path));
        }
        return results;
    }

    /**
     * Helper method to list out all files under a specified path. The specified {@link PathFilter} is treated as a file
     * filter, that is it is only applied to file {@link Path}s.
     */
    public static List<FileStatus> listFilesRecursively(FileSystem fs, Path path, PathFilter fileFilter)
            throws IOException {
        return listFilesRecursivelyHelper(fs, Lists.<FileStatus>newArrayList(), fs.getFileStatus(path), fileFilter,
                false);
    }

    /**
     * Helper method to list out all files under a specified path. If applyFilterToDirectories is false, the supplied
     * {@link PathFilter} will only be applied to files.
     */
    public static List<FileStatus> listFilesRecursively(FileSystem fs, Path path, PathFilter fileFilter,
            boolean applyFilterToDirectories) throws IOException {
        return listFilesRecursivelyHelper(fs, Lists.<FileStatus>newArrayList(), fs.getFileStatus(path), fileFilter,
                applyFilterToDirectories);
    }

    private static List<FileStatus> listFilesRecursivelyHelper(FileSystem fs, List<FileStatus> files,
            FileStatus fileStatus, PathFilter fileFilter, boolean applyFilterToDirectories)
            throws FileNotFoundException, IOException {
        if (fileStatus.isDirectory()) {
            for (FileStatus status : fs.listStatus(fileStatus.getPath(),
                    applyFilterToDirectories ? fileFilter : NO_OP_PATH_FILTER)) {
                if (fileStatus.isDirectory()) {
                    listFilesRecursivelyHelper(fs, files, status, fileFilter, applyFilterToDirectories);
                } else {
                    files.add(fileStatus);
                }
            }
        } else if (fileFilter.accept(fileStatus.getPath())) {
            files.add(fileStatus);
        }
        return files;
    }

    /**
     * Method to list out all files, or directory if no file exists, under a specified path.
     */
    public static List<FileStatus> listMostNestedPathRecursively(FileSystem fs, Path path) throws IOException {
        return listMostNestedPathRecursively(fs, path, NO_OP_PATH_FILTER);
    }

    public static List<FileStatus> listMostNestedPathRecursively(FileSystem fs, Iterable<Path> paths)
            throws IOException {
        List<FileStatus> results = Lists.newArrayList();
        for (Path path : paths) {
            results.addAll(listMostNestedPathRecursively(fs, path));
        }
        return results;
    }

    /**
     * Method to list out all files, or directory if no file exists, under a specified path.
     * The specified {@link PathFilter} is treated as a file filter, that is it is only applied to file {@link Path}s.
     */
    public static List<FileStatus> listMostNestedPathRecursively(FileSystem fs, Path path, PathFilter fileFilter)
            throws IOException {
        return listMostNestedPathRecursivelyHelper(fs, Lists.<FileStatus>newArrayList(), fs.getFileStatus(path),
                fileFilter);
    }

    private static List<FileStatus> listMostNestedPathRecursivelyHelper(FileSystem fs, List<FileStatus> files,
            FileStatus fileStatus, PathFilter fileFilter) throws IOException {
        if (fileStatus.isDirectory()) {
            FileStatus[] curFileStatus = fs.listStatus(fileStatus.getPath());
            if (ArrayUtils.isEmpty(curFileStatus)) {
                files.add(fileStatus);
            } else {
                for (FileStatus status : curFileStatus) {
                    listMostNestedPathRecursivelyHelper(fs, files, status, fileFilter);
                }
            }
        } else if (fileFilter.accept(fileStatus.getPath())) {
            files.add(fileStatus);
        }
        return files;
    }

    /**
     * Helper method to list out all paths under a specified path. If the {@link org.apache.hadoop.fs.FileSystem} is
     * unable to list the contents of a relevant directory, will log an error and skip.
     */
    public static List<FileStatus> listPathsRecursively(FileSystem fs, Path path, PathFilter fileFilter)
            throws IOException {
        return listPathsRecursivelyHelper(fs, Lists.<FileStatus>newArrayList(), fs.getFileStatus(path), fileFilter);
    }

    private static List<FileStatus> listPathsRecursivelyHelper(FileSystem fs, List<FileStatus> files,
            FileStatus fileStatus, PathFilter fileFilter) {
        if (fileFilter.accept(fileStatus.getPath())) {
            files.add(fileStatus);
        }
        if (fileStatus.isDirectory()) {
            try {
                for (FileStatus status : fs.listStatus(fileStatus.getPath())) {
                    listPathsRecursivelyHelper(fs, files, status, fileFilter);
                }
            } catch (IOException ioe) {
                LOG.error("Could not list contents of path " + fileStatus.getPath());
            }
        }
        return files;
    }
}