如何将具有属性/权限的目录从一个位置复制到另一个位置?

问题描述

我看到很多示例，这些示例使用Files.walkFileTree()将目录及其内容从一个位置复制到另一个位置，但是他们没有考虑目录的文件属性和权限.意思是，他们只是调用Files.createDirectories()而没有任何属性或权限.

I see a lot of examples that use Files.walkFileTree() to copy a directory and its contents from one location to another, but they fail to take the directory's file attributes and permissions into consideration. Meaning, they just invoke Files.createDirectories() without any attributes or permissions.

如何使用Java7核心类将目录(及其内容)从一个位置复制到另一个位置而又不丢失文件属性或权限?

How does one copy a directory (and its contents) from one location to another without losing file attributes or permissions, using the Java7 core classes?

推荐答案

回答我自己的问题:

/**
 * Copies a directory.
 * <p>
 * NOTE: This method is not thread-safe.
 * <p>
 *
 * @param source
 *            the directory to copy from
 * @param target
 *            the directory to copy into
 * @throws IOException
 *             if an I/O error occurs
 */
private static void copyDirectory(final Path source, final Path target)
        throws IOException {
    Files.walkFileTree(source, EnumSet.of(FileVisitOption.FOLLOW_LINKS),
        Integer.MAX_VALUE, new FileVisitor<Path>() {

            @Override
            public FileVisitResult preVisitDirectory(Path dir,
                    BasicFileAttributes sourceBasic) throws IOException {
                Path targetDir = Files.createDirectories(target
                    .resolve(source.relativize(dir)));
                AclFileAttributeView acl = Files.getFileAttributeView(dir,
                    AclFileAttributeView.class);
                if (acl != null)
                    Files.getFileAttributeView(targetDir,
                        AclFileAttributeView.class).setAcl(acl.getAcl());
                DosFileAttributeView dosAttrs = Files.getFileAttributeView(
                    dir, DosFileAttributeView.class);
                if (dosAttrs != null) {
                    DosFileAttributes sourceDosAttrs = dosAttrs
                        .readAttributes();
                    DosFileAttributeView targetDosAttrs = Files
                        .getFileAttributeView(targetDir,
                            DosFileAttributeView.class);
                    targetDosAttrs.setArchive(sourceDosAttrs.isArchive());
                    targetDosAttrs.setHidden(sourceDosAttrs.isHidden());
                    targetDosAttrs.setReadOnly(sourceDosAttrs.isReadOnly());
                    targetDosAttrs.setSystem(sourceDosAttrs.isSystem());
                }
                FileOwnerAttributeView ownerAttrs = Files
                    .getFileAttributeView(dir, FileOwnerAttributeView.class);
                if (ownerAttrs != null) {
                    FileOwnerAttributeView targetOwner = Files
                        .getFileAttributeView(targetDir,
                            FileOwnerAttributeView.class);
                    targetOwner.setOwner(ownerAttrs.getOwner());
                }
                PosixFileAttributeView posixAttrs = Files
                    .getFileAttributeView(dir, PosixFileAttributeView.class);
                if (posixAttrs != null) {
                    PosixFileAttributes sourcePosix = posixAttrs
                        .readAttributes();
                    PosixFileAttributeView targetPosix = Files
                        .getFileAttributeView(targetDir,
                            PosixFileAttributeView.class);
                    targetPosix.setPermissions(sourcePosix.permissions());
                    targetPosix.setGroup(sourcePosix.group());
                }
                UserDefinedFileAttributeView userAttrs = Files
                    .getFileAttributeView(dir,
                        UserDefinedFileAttributeView.class);
                if (userAttrs != null) {
                    UserDefinedFileAttributeView targetUser = Files
                        .getFileAttributeView(targetDir,
                            UserDefinedFileAttributeView.class);
                    for (String key : userAttrs.list()) {
                        ByteBuffer buffer = ByteBuffer.allocate(userAttrs
                            .size(key));
                        userAttrs.read(key, buffer);
                        buffer.flip();
                        targetUser.write(key, buffer);
                    }
                }
                // Must be done last, otherwise last-modified time may be
                // wrong
                BasicFileAttributeView targetBasic = Files
                    .getFileAttributeView(targetDir,
                        BasicFileAttributeView.class);
                targetBasic.setTimes(sourceBasic.lastModifiedTime(),
                    sourceBasic.lastAccessTime(),
                    sourceBasic.creationTime());
                return FileVisitResult.CONTINUE;
            }

            @Override
            public FileVisitResult visitFile(Path file,
                    BasicFileAttributes attrs) throws IOException {
                Files.copy(file, target.resolve(source.relativize(file)),
                    StandardCopyOption.COPY_ATTRIBUTES);
                return FileVisitResult.CONTINUE;
            }

            @Override
            public FileVisitResult
                    visitFileFailed(Path file, IOException e)
                            throws IOException {
                throw e;
            }

            @Override
            public FileVisitResult postVisitDirectory(Path dir,
                    IOException e) throws IOException {
                if (e != null) throw e;
                return FileVisitResult.CONTINUE;
            }
        });
}

此代码尚未经过广泛测试，但对我有用.

This code hasn't been tested extensively, but it works for me.

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