001/*
002 * Copyright 2002-2017 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.util;
018
019import java.io.File;
020import java.io.IOException;
021
022/**
023 * Utility methods for working with the file system.
024 *
025 * @author Rob Harrop
026 * @author Juergen Hoeller
027 * @since 2.5.3
028 */
029public abstract class FileSystemUtils {
030
031        /**
032         * Delete the supplied {@link File} - for directories,
033         * recursively delete any nested directories or files as well.
034         * @param root the root {@code File} to delete
035         * @return {@code true} if the {@code File} was deleted,
036         * otherwise {@code false}
037         */
038        public static boolean deleteRecursively(File root) {
039                if (root != null && root.exists()) {
040                        if (root.isDirectory()) {
041                                File[] children = root.listFiles();
042                                if (children != null) {
043                                        for (File child : children) {
044                                                deleteRecursively(child);
045                                        }
046                                }
047                        }
048                        return root.delete();
049                }
050                return false;
051        }
052
053        /**
054         * Recursively copy the contents of the {@code src} file/directory
055         * to the {@code dest} file/directory.
056         * @param src the source directory
057         * @param dest the destination directory
058         * @throws IOException in the case of I/O errors
059         */
060        public static void copyRecursively(File src, File dest) throws IOException {
061                Assert.isTrue(src != null && (src.isDirectory() || src.isFile()),
062                                "Source File must denote a directory or file");
063                Assert.notNull(dest, "Destination File must not be null");
064                doCopyRecursively(src, dest);
065        }
066
067        /**
068         * Actually copy the contents of the {@code src} file/directory
069         * to the {@code dest} file/directory.
070         * @param src the source directory
071         * @param dest the destination directory
072         * @throws IOException in the case of I/O errors
073         */
074        private static void doCopyRecursively(File src, File dest) throws IOException {
075                if (src.isDirectory()) {
076                        dest.mkdir();
077                        File[] entries = src.listFiles();
078                        if (entries == null) {
079                                throw new IOException("Could not list files in directory: " + src);
080                        }
081                        for (File entry : entries) {
082                                doCopyRecursively(entry, new File(dest, entry.getName()));
083                        }
084                }
085                else if (src.isFile()) {
086                        try {
087                                dest.createNewFile();
088                        }
089                        catch (IOException ex) {
090                                throw new IOException("Failed to create file: " + dest, ex);
091                        }
092                        FileCopyUtils.copy(src, dest);
093                }
094                else {
095                        // Special File handle: neither a file not a directory.
096                        // Simply skip it when contained in nested directory...
097                }
098        }
099
100}