/* * 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.attribute; import java.io.IOException; /** * A file attribute view that provides a view of a basic set of file * attributes common to many file systems. The basic set of file attributes * consist of mandatory and optional file attributes as * defined by the {@link BasicFileAttributes} interface. *
The file attributes are retrieved from the file system as a bulk * operation by invoking the {@link #readAttributes() readAttributes} method. * This class also defines the {@link #setTimes setTimes} method to update the * file's time attributes. * *
Where dynamic access to file attributes is required, the attributes * supported by this attribute view have the following names and types: *
** **
** *Name *Type ** *"lastModifiedTime" *{@link FileTime} ** *"lastAccessTime" *{@link FileTime} ** *"creationTime" *{@link FileTime} ** *"size" *{@link Long} ** *"isRegularFile" *{@link Boolean} ** *"isDirectory" *{@link Boolean} ** *"isSymbolicLink" *{@link Boolean} ** *"isOther" *{@link Boolean} ** *"fileKey" *{@link Object} *
The {@link java.nio.file.Files#getAttribute getAttribute} method may be * used to read any of these attributes as if by invoking the {@link * #readAttributes() readAttributes()} method. * *
The {@link java.nio.file.Files#setAttribute setAttribute} method may be * used to update the file's last modified time, last access time or create time * attributes as if by invoking the {@link #setTimes setTimes} method. * * @since 1.7 */ public interface BasicFileAttributeView extends FileAttributeView { /** * Returns the name of the attribute view. Attribute views of this type * have the name {@code "basic"}. */ @Override String name(); /** * Reads the basic file attributes as a bulk operation. * *
It is implementation specific if all file attributes are read as an * atomic operation with respect to other file system operations. * * @return the file attributes * * @throws IOException * if an I/O error occurs * @throws SecurityException * In the case of the default provider, a security manager is * installed, its {@link SecurityManager#checkRead(String) checkRead} * method is invoked to check read access to the file */ BasicFileAttributes readAttributes() throws IOException; /** * Updates any or all of the file's last modified time, last access time, * and create time attributes. * *
This method updates the file's timestamp attributes. The values are * converted to the epoch and precision supported by the file system. * Converting from finer to coarser granularities result in precision loss. * The behavior of this method when attempting to set a timestamp that is * not supported or to a value that is outside the range supported by the * underlying file store is not defined. It may or not fail by throwing an * {@code IOException}. * *
If any of the {@code lastModifiedTime}, {@code lastAccessTime}, * or {@code createTime} parameters has the value {@code null} then the * corresponding timestamp is not changed. An implementation may require to * read the existing values of the file attributes when only some, but not * all, of the timestamp attributes are updated. Consequently, this method * may not be an atomic operation with respect to other file system * operations. Reading and re-writing existing values may also result in * precision loss. If all of the {@code lastModifiedTime}, {@code * lastAccessTime} and {@code createTime} parameters are {@code null} then * this method has no effect. * *
Usage Example: * Suppose we want to change a file's creation time. *
* Path path = ... * FileTime time = ... * Files.getFileAttributeView(path, BasicFileAttributeView.class).setTimes(null, null, time); ** * @param lastModifiedTime * the new last modified time, or {@code null} to not change the * value * @param lastAccessTime * the last access time, or {@code null} to not change the value * @param createTime * the file's create time, or {@code null} to not change the value * * @throws IOException * if an I/O error occurs * @throws SecurityException * In the case of the default provider, a security manager is * installed, its {@link SecurityManager#checkWrite(String) checkWrite} * method is invoked to check write access to the file * * @see java.nio.file.Files#setLastModifiedTime */ void setTimes(FileTime lastModifiedTime, FileTime lastAccessTime, FileTime createTime) throws IOException; }