| /* |
| * |
| * 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.qpid.server.util; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.nio.file.AtomicMoveNotSupportedException; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| import java.nio.file.StandardCopyOption; |
| import java.nio.file.attribute.PosixFileAttributeView; |
| import java.nio.file.attribute.PosixFilePermission; |
| import java.nio.file.attribute.PosixFilePermissions; |
| import java.util.Set; |
| |
| public class FileHelper |
| { |
| |
| public void writeFileSafely(Path targetFile, BaseAction<File, IOException> operation) throws IOException |
| { |
| String name = targetFile.toFile().getName(); |
| writeFileSafely(targetFile, |
| targetFile.resolveSibling(name + ".bak"), |
| targetFile.resolveSibling(name + ".tmp"), |
| operation); |
| } |
| |
| public void writeFileSafely(Path targetFile, Path backupFile, Path tmpFile, BaseAction<File, IOException> write) throws IOException |
| { |
| Files.deleteIfExists(tmpFile); |
| Files.deleteIfExists(backupFile); |
| |
| Set<PosixFilePermission> permissions = null; |
| if (Files.exists(targetFile) && isPosixFileSystem(targetFile)) |
| { |
| permissions = Files.getPosixFilePermissions(targetFile); |
| } |
| |
| tmpFile = createNewFile(tmpFile, permissions); |
| |
| write.performAction(tmpFile.toFile()); |
| |
| atomicFileMoveOrReplace(targetFile, backupFile); |
| |
| if (permissions != null) |
| { |
| Files.setPosixFilePermissions(backupFile, permissions); |
| } |
| |
| atomicFileMoveOrReplace(tmpFile, targetFile); |
| |
| Files.deleteIfExists(tmpFile); |
| Files.deleteIfExists(backupFile); |
| } |
| |
| public Path createNewFile(File newFile, String posixFileAttributes) throws IOException |
| { |
| return createNewFile(newFile.toPath(), posixFileAttributes); |
| } |
| |
| public Path createNewFile(Path newFile, String posixFileAttributes) throws IOException |
| { |
| Set<PosixFilePermission> permissions = posixFileAttributes == null ? null : PosixFilePermissions.fromString(posixFileAttributes); |
| return createNewFile(newFile, permissions ); |
| } |
| |
| public Path createNewFile(Path newFile, Set<PosixFilePermission> permissions) throws IOException |
| { |
| if (!Files.exists(newFile)) |
| { |
| newFile = Files.createFile(newFile); |
| } |
| |
| if (permissions != null && isPosixFileSystem(newFile)) |
| { |
| Files.setPosixFilePermissions(newFile, permissions); |
| } |
| |
| return newFile; |
| } |
| |
| public boolean isPosixFileSystem(Path path) throws IOException |
| { |
| while (!Files.exists(path)) |
| { |
| path = path.getParent(); |
| |
| if (path == null) |
| { |
| return false; |
| } |
| } |
| return Files.getFileAttributeView(path, PosixFileAttributeView.class) != null; |
| } |
| |
| public Path atomicFileMoveOrReplace(Path sourceFile, Path targetFile) throws IOException |
| { |
| try |
| { |
| return Files.move(sourceFile, targetFile, StandardCopyOption.ATOMIC_MOVE, StandardCopyOption.REPLACE_EXISTING); |
| } |
| catch(AtomicMoveNotSupportedException e) |
| { |
| if (sourceFile.toFile().renameTo(targetFile.toFile())) |
| { |
| return targetFile; |
| } |
| else |
| { |
| throw new RuntimeException("Atomic move is unsupported and rename from : '" |
| + sourceFile + "' to: '" + targetFile + "' failed."); |
| } |
| } |
| } |
| |
| public boolean isWritableDirectory(String path) |
| { |
| File storePath = new File(path).getAbsoluteFile(); |
| if (storePath.exists()) |
| { |
| if (!storePath.isDirectory()) |
| { |
| return false; |
| } |
| } |
| else |
| { |
| do |
| { |
| storePath = storePath.getParentFile(); |
| if (storePath == null) |
| { |
| return false; |
| } |
| } |
| while (!storePath.exists()); |
| } |
| return storePath.canWrite(); |
| } |
| |
| } |