/*
* SonarQube
* Copyright (C) 2009-2017 SonarSource SA
* mailto:info AT sonarsource DOT com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package org.sonar.core.util;
import java.io.File;
import java.io.IOException;
import java.nio.file.FileVisitOption;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.EnumSet;
import javax.annotation.Nullable;
import static com.google.common.base.Preconditions.checkArgument;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
/**
* This utility class provides Java NIO based replacement for some methods of
* {@link org.apache.commons.io.FileUtils Common IO FileUtils} class.
*/
public final class FileUtils {
private static final String DIRECTORY_CAN_NOT_BE_NULL = "Directory can not be null";
private static final EnumSet<FileVisitOption> FOLLOW_LINKS = EnumSet.of(FileVisitOption.FOLLOW_LINKS);
private FileUtils() {
// prevents instantiation
}
/**
* Deletes a directory recursively.
*
* @param directory directory to delete
* @throws IOException in case deletion is unsuccessful
*/
public static void deleteDirectory(File directory) throws IOException {
requireNonNull(directory, DIRECTORY_CAN_NOT_BE_NULL);
deleteDirectoryImpl(directory.toPath());
}
/**
* Cleans a directory recursively.
*
* @param directory directory to delete
* @throws IOException in case deletion is unsuccessful
*/
public static void cleanDirectory(File directory) throws IOException {
requireNonNull(directory, DIRECTORY_CAN_NOT_BE_NULL);
Path path = directory.toPath();
if (!path.toFile().exists()) {
return;
}
cleanDirectoryImpl(path);
}
/**
* Deletes a file, never throwing an exception. If file is a directory, delete it and all sub-directories.
* <p>
* The difference between File.delete() and this method are:
* <ul>
* <li>A directory to be deleted does not have to be empty.</li>
* <li>No exceptions are thrown when a file or directory cannot be deleted.</li>
* </ul>
*
* @param file file or directory to delete, can be {@code null}
* @return {@code true} if the file or directory was deleted, otherwise {@code false}
*/
public static boolean deleteQuietly(@Nullable File file) {
if (file == null) {
return false;
}
try {
if (file.isDirectory()) {
deleteDirectory(file);
} else {
Files.delete(file.toPath());
}
return true;
} catch (IOException | SecurityException ignored) {
return false;
}
}
private static void checkIO(boolean condition, String pattern, Object... arguments) throws IOException {
if (!condition) {
throw new IOException(format(pattern, arguments));
}
}
private static void cleanDirectoryImpl(Path path) throws IOException {
checkArgument(path.toFile().isDirectory(), "'%s' is not a directory", path);
Files.walkFileTree(path, FOLLOW_LINKS, CleanDirectoryFileVisitor.VISIT_MAX_DEPTH, new CleanDirectoryFileVisitor(path));
}
private static void deleteDirectoryImpl(Path path) throws IOException {
requireNonNull(path, DIRECTORY_CAN_NOT_BE_NULL);
File file = path.toFile();
if (!file.exists()) {
return;
}
checkIO(!Files.isSymbolicLink(path), "Directory '%s' is a symbolic link", path);
checkIO(!file.isFile(), "Directory '%s' is a file", path);
Files.walkFileTree(path, DeleteRecursivelyFileVisitor.INSTANCE);
checkIO(!file.exists(), "Unable to delete directory '%s'", path);
}
/**
* This visitor is intended to be used to visit direct children of directory <strong>or a symLink to a directory</strong>,
* so, with a max depth of {@link #VISIT_MAX_DEPTH 1}. Each direct children will either be directly deleted (if file)
* or recursively deleted (if directory).
*/
private static class CleanDirectoryFileVisitor extends SimpleFileVisitor<Path> {
public static final int VISIT_MAX_DEPTH = 1;
private final Path path;
private final boolean symLink;
public CleanDirectoryFileVisitor(Path path) {
this.path = path;
this.symLink = Files.isSymbolicLink(path);
}
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
if (file.toFile().isDirectory()) {
deleteDirectoryImpl(file);
} else if (!symLink || !file.equals(path)) {
Files.delete(file);
}
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
if (!dir.equals(path)) {
deleteDirectoryImpl(dir);
}
return FileVisitResult.CONTINUE;
}
}
private static final class DeleteRecursivelyFileVisitor extends SimpleFileVisitor<Path> {
public static final DeleteRecursivelyFileVisitor INSTANCE = new DeleteRecursivelyFileVisitor();
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
Files.delete(file);
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
Files.delete(dir);
return FileVisitResult.CONTINUE;
}
}
}