/* * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved. * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. * * * * * * * * * * * * * * * * * * * * */ package java.nio.file; import java.nio.file.attribute.*; import java.nio.channels.SeekableByteChannel; import java.util.Set; import java.io.IOException; /** * A {@code DirectoryStream} that defines operations on files that are located * relative to an open directory. A {@code SecureDirectoryStream} is intended * for use by sophisticated or security sensitive applications requiring to * traverse file trees or otherwise operate on directories in a race-free manner. * Race conditions can arise when a sequence of file operations cannot be * carried out in isolation. Each of the file operations defined by this * interface specify a relative path. All access to the file is relative * to the open directory irrespective of if the directory is moved or replaced * by an attacker while the directory is open. A {@code SecureDirectoryStream} * may also be used as a virtual working directory. * *

A {@code SecureDirectoryStream} requires corresponding support from the * underlying operating system. Where an implementation supports this features * then the {@code DirectoryStream} returned by the {@link Files#newDirectoryStream * newDirectoryStream} method will be a {@code SecureDirectoryStream} and must * be cast to that type in order to invoke the methods defined by this interface. * *

In the case of the default {@link java.nio.file.spi.FileSystemProvider * provider}, and a security manager is set, then the permission checks are * performed using the path obtained by resolving the given relative path * against the original path of the directory (irrespective of if the * directory is moved since it was opened). * * @since 1.7 */ public interface SecureDirectoryStream extends DirectoryStream { /** * Opens the directory identified by the given path, returning a {@code * SecureDirectoryStream} to iterate over the entries in the directory. * *

This method works in exactly the manner specified by the {@link * Files#newDirectoryStream(Path) newDirectoryStream} method for the case that * the {@code path} parameter is an {@link Path#isAbsolute absolute} path. * When the parameter is a relative path then the directory to open is * relative to this open directory. The {@link * LinkOption#NOFOLLOW_LINKS NOFOLLOW_LINKS} option may be used to * ensure that this method fails if the file is a symbolic link. * *

The new directory stream, once created, is not dependent upon the * directory stream used to create it. Closing this directory stream has no * effect upon newly created directory stream. * * @param path * the path to the directory to open * @param options * options indicating how symbolic links are handled * * @return a new and open {@code SecureDirectoryStream} object * * @throws ClosedDirectoryStreamException * if the directory stream is closed * @throws NotDirectoryException * if the file could not otherwise be opened because it is not * a directory (optional specific exception) * @throws IOException * if an I/O error occurs * @throws SecurityException * In the case of the default provider, and a security manager is * installed, the {@link SecurityManager#checkRead(String) checkRead} * method is invoked to check read access to the directory. */ SecureDirectoryStream newDirectoryStream(T path, LinkOption... options) throws IOException; /** * Opens or creates a file in this directory, returning a seekable byte * channel to access the file. * *

This method works in exactly the manner specified by the {@link * Files#newByteChannel Files.newByteChannel} method for the * case that the {@code path} parameter is an {@link Path#isAbsolute absolute} * path. When the parameter is a relative path then the file to open or * create is relative to this open directory. In addition to the options * defined by the {@code Files.newByteChannel} method, the {@link * LinkOption#NOFOLLOW_LINKS NOFOLLOW_LINKS} option may be used to * ensure that this method fails if the file is a symbolic link. * *

The channel, once created, is not dependent upon the directory stream * used to create it. Closing this directory stream has no effect upon the * channel. * * @param path * the path of the file to open open or create * @param options * options specifying how the file is opened * @param attrs * an optional list of attributes to set atomically when creating * the file * * @throws ClosedDirectoryStreamException * if the directory stream is closed * @throws IllegalArgumentException * if the set contains an invalid combination of options * @throws UnsupportedOperationException * if an unsupported open option is specified or the array contains * attributes that cannot be set atomically when creating the file * @throws FileAlreadyExistsException * if a file of that name already exists and the {@link * StandardOpenOption#CREATE_NEW CREATE_NEW} option is specified * (optional specific exception) * @throws IOException * if an I/O error occurs * @throws SecurityException * In the case of the default provider, and a security manager is * installed, the {@link SecurityManager#checkRead(String) checkRead} * method is invoked to check read access to the path if the file * is opened for reading. The {@link SecurityManager#checkWrite(String) * checkWrite} method is invoked to check write access to the path * if the file is opened for writing. */ SeekableByteChannel newByteChannel(T path, Set options, FileAttribute... attrs) throws IOException; /** * Deletes a file. * *

Unlike the {@link Files#delete delete()} method, this method does * not first examine the file to determine if the file is a directory. * Whether a directory is deleted by this method is system dependent and * therefore not specified. If the file is a symbolic link, then the link * itself, not the final target of the link, is deleted. When the * parameter is a relative path then the file to delete is relative to * this open directory. * * @param path * the path of the file to delete * * @throws ClosedDirectoryStreamException * if the directory stream is closed * @throws NoSuchFileException * if the file does not exist (optional specific exception) * @throws IOException * if an I/O error occurs * @throws SecurityException * In the case of the default provider, and a security manager is * installed, the {@link SecurityManager#checkDelete(String) checkDelete} * method is invoked to check delete access to the file */ void deleteFile(T path) throws IOException; /** * Deletes a directory. * *

Unlike the {@link Files#delete delete()} method, this method * does not first examine the file to determine if the file is a directory. * Whether non-directories are deleted by this method is system dependent and * therefore not specified. When the parameter is a relative path then the * directory to delete is relative to this open directory. * * @param path * the path of the directory to delete * * @throws ClosedDirectoryStreamException * if the directory stream is closed * @throws NoSuchFileException * if the directory does not exist (optional specific exception) * @throws DirectoryNotEmptyException * if the directory could not otherwise be deleted because it is * not empty (optional specific exception) * @throws IOException * if an I/O error occurs * @throws SecurityException * In the case of the default provider, and a security manager is * installed, the {@link SecurityManager#checkDelete(String) checkDelete} * method is invoked to check delete access to the directory */ void deleteDirectory(T path) throws IOException; /** * Move a file from this directory to another directory. * *

This method works in a similar manner to {@link Files#move move} * method when the {@link StandardCopyOption#ATOMIC_MOVE ATOMIC_MOVE} option * is specified. That is, this method moves a file as an atomic file system * operation. If the {@code srcpath} parameter is an {@link Path#isAbsolute * absolute} path then it locates the source file. If the parameter is a * relative path then it is located relative to this open directory. If * the {@code targetpath} parameter is absolute then it locates the target * file (the {@code targetdir} parameter is ignored). If the parameter is * a relative path it is located relative to the open directory identified * by the {@code targetdir} parameter. In all cases, if the target file * exists then it is implementation specific if it is replaced or this * method fails. * * @param srcpath * the name of the file to move * @param targetdir * the destination directory * @param targetpath * the name to give the file in the destination directory * * @throws ClosedDirectoryStreamException * if this or the target directory stream is closed * @throws FileAlreadyExistsException * if the file already exists in the target directory and cannot * be replaced (optional specific exception) * @throws AtomicMoveNotSupportedException * if the file cannot be moved as an atomic file system operation * @throws IOException * if an I/O error occurs * @throws SecurityException * In the case of the default provider, and a security manager is * installed, the {@link SecurityManager#checkWrite(String) checkWrite} * method is invoked to check write access to both the source and * target file. */ void move(T srcpath, SecureDirectoryStream targetdir, T targetpath) throws IOException; /** * Returns a new file attribute view to access the file attributes of this * directory. * *

The resulting file attribute view can be used to read or update the * attributes of this (open) directory. The {@code type} parameter specifies * the type of the attribute view and the method returns an instance of that * type if supported. Invoking this method to obtain a {@link * BasicFileAttributeView} always returns an instance of that class that is * bound to this open directory. * *

The state of resulting file attribute view is intimately connected * to this directory stream. Once the directory stream is {@link #close closed}, * then all methods to read or update attributes will throw {@link * ClosedDirectoryStreamException ClosedDirectoryStreamException}. * * @param type * the {@code Class} object corresponding to the file attribute view * * @return a new file attribute view of the specified type bound to * this directory stream, or {@code null} if the attribute view * type is not available */ V getFileAttributeView(Class type); /** * Returns a new file attribute view to access the file attributes of a file * in this directory. * *

The resulting file attribute view can be used to read or update the * attributes of file in this directory. The {@code type} parameter specifies * the type of the attribute view and the method returns an instance of that * type if supported. Invoking this method to obtain a {@link * BasicFileAttributeView} always returns an instance of that class that is * bound to the file in the directory. * *

The state of resulting file attribute view is intimately connected * to this directory stream. Once the directory stream {@link #close closed}, * then all methods to read or update attributes will throw {@link * ClosedDirectoryStreamException ClosedDirectoryStreamException}. The * file is not required to exist at the time that the file attribute view * is created but methods to read or update attributes of the file will * fail when invoked and the file does not exist. * * @param path * the path of the file * @param type * the {@code Class} object corresponding to the file attribute view * @param options * options indicating how symbolic links are handled * * @return a new file attribute view of the specified type bound to a * this directory stream, or {@code null} if the attribute view * type is not available * */ V getFileAttributeView(T path, Class type, LinkOption... options); }