| /** |
| * 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 org.apache.hadoop.sqoop.util; |
| |
| import java.util.Arrays; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| |
| /** |
| * Recursive file listing under a specified directory. |
| * |
| * Taken from http://www.javapractices.com/topic/TopicAction.do?Id=68 |
| * Used under the terms of the CC Attribution license: |
| * http://creativecommons.org/licenses/by/3.0/ |
| * |
| * Method by Alex Wong (javapractices.com) |
| */ |
| public final class FileListing { |
| |
| private FileListing() { } |
| |
| /** |
| * Demonstrate use. |
| * |
| * @param aArgs - <tt>aArgs[0]</tt> is the full name of an existing |
| * directory that can be read. |
| */ |
| public static void main(String... aArgs) throws FileNotFoundException { |
| File startingDirectory = new File(aArgs[0]); |
| List<File> files = FileListing.getFileListing(startingDirectory); |
| |
| //print out all file names, in the the order of File.compareTo() |
| for (File file : files) { |
| System.out.println(file); |
| } |
| } |
| |
| /** |
| * Recursively walk a directory tree and return a List of all |
| * Files found; the List is sorted using File.compareTo(). |
| * |
| * @param aStartingDir is a valid directory, which can be read. |
| */ |
| public static List<File> getFileListing(File aStartingDir) throws FileNotFoundException { |
| validateDirectory(aStartingDir); |
| List<File> result = getFileListingNoSort(aStartingDir); |
| Collections.sort(result); |
| return result; |
| } |
| |
| // PRIVATE // |
| private static List<File> getFileListingNoSort(File aStartingDir) throws FileNotFoundException { |
| List<File> result = new ArrayList<File>(); |
| File[] filesAndDirs = aStartingDir.listFiles(); |
| List<File> filesDirs = Arrays.asList(filesAndDirs); |
| for (File file : filesDirs) { |
| result.add(file); //always add, even if directory |
| if (!file.isFile()) { |
| //must be a directory |
| //recursive call! |
| List<File> deeperList = getFileListingNoSort(file); |
| result.addAll(deeperList); |
| } |
| } |
| return result; |
| } |
| |
| /** |
| * Directory is valid if it exists, does not represent a file, and can be read. |
| */ |
| private static void validateDirectory(File aDirectory) throws FileNotFoundException { |
| if (aDirectory == null) { |
| throw new IllegalArgumentException("Directory should not be null."); |
| } |
| if (!aDirectory.exists()) { |
| throw new FileNotFoundException("Directory does not exist: " + aDirectory); |
| } |
| if (!aDirectory.isDirectory()) { |
| throw new IllegalArgumentException("Is not a directory: " + aDirectory); |
| } |
| if (!aDirectory.canRead()) { |
| throw new IllegalArgumentException("Directory cannot be read: " + aDirectory); |
| } |
| } |
| |
| /** |
| * Recursively delete a directory and all its children |
| * @param aStartingDir is a valid directory. |
| */ |
| public static void recursiveDeleteDir(File dir) throws IOException { |
| if (!dir.exists()) { |
| throw new FileNotFoundException(dir.toString() + " does not exist"); |
| } |
| |
| if (dir.isDirectory()) { |
| // recursively descend into all children and delete them. |
| File [] children = dir.listFiles(); |
| for (File child : children) { |
| recursiveDeleteDir(child); |
| } |
| } |
| |
| if (!dir.delete()) { |
| throw new IOException("Could not remove: " + dir); |
| } |
| } |
| } |
| |