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Interfaces and classes providing access to file and file system attributes.

    
Attribute views

Attribute views
    
Description


AttributeView
    
Can read or update non-opaque values associated with objects in a file system

    FileAttributeView
    
Can read or update file attributes

    
    BasicFileAttributeView
    
Can read or update a basic set of file attributes

    
    PosixFileAttributeView
    
Can read or update POSIX defined file attributes

    
    DosFileAttributeView
    
Can read or update FAT file attributes

    
    FileOwnerAttributeView
    
Can read or update the owner of a file

    
    AclFileAttributeView
    
Can read or update Access Control Lists

    
    UserDefinedFileAttributeView
    
Can read or update user-defined file attributes

    FileStoreAttributeView
    
Can read or update file system attributes


 An attribute view provides a read-only or updatable view of the non-opaque
values, or metadata, associated with objects in a file system. The FileAttributeView interface is extended by several other interfaces that provide views to specific sets of file attributes. FileAttributeViews are selected by invoking the Files.getFileAttributeView method with a type-token to identify the required view. Views can also be identified by name. The FileStoreAttributeView interface provides access to file store attributes. A FileStoreAttributeView of a given type is obtained by invoking the FileStore.getFileStoreAttributeView method. 
 The BasicFileAttributeView class defines methods to read and update a basic set of file
attributes that are common to many file systems.
 The PosixFileAttributeView interface extends BasicFileAttributeView by defining methods to access the file attributes commonly used by file systems and operating systems that implement the Portable Operating System Interface (POSIX) family of standards. 
 The DosFileAttributeView class extends BasicFileAttributeView by defining methods to access the legacy "DOS" file attributes supported on file systems such as File Allocation Tabl (FAT), commonly used in consumer devices. 
 The AclFileAttributeView class defines methods to read and write the Access Control List (ACL) file attribute. The ACL model used by this file attribute view is based on the model defined by 
RFC 3530: Network File System (NFS) version 4 Protocol.
 In addition to attribute views, this package also defines classes and
interfaces that are used when accessing attributes:

  
 The UserPrincipal and GroupPrincipal interfaces represent an identity or group identity. 
  
 The UserPrincipalLookupService interface defines methods to lookup user or group principals. 
  
 The FileAttribute interface represents the value of an attribute for cases where the attribute value is required to be set atomically when creating an object in the file system. 

 Unless otherwise noted, passing a null argument to a constructor or method in any class or interface in this package will cause a NullPointerException to be thrown. 
Since:
1.7/**
 * Interfaces and classes providing access to file and file system attributes.
 *
 * <table class="striped" style="padding-left:2em; text-align:left">
 *     <caption style="display:none">Attribute views</caption>
 * <thead>
 * <tr><th scope="col">Attribute views</th>
 *     <th scope="col">Description</th></tr>
 * </thead>
 * <tbody>
 * <tr><th scope="row"><i>{@link java.nio.file.attribute.AttributeView}</i></th>
 *     <td>Can read or update non-opaque values associated with objects in a file system</td></tr>
 * <tr><th scope="row">
 *     <span style="padding-left:1em"><i>{@link java.nio.file.attribute.FileAttributeView}</i></span></th>
 *     <td>Can read or update file attributes</td></tr>
 * <tr><th scope="row">
 *     <span style="padding-left:2em">
 *     <i>{@link java.nio.file.attribute.BasicFileAttributeView}</i></span></th>
 *     <td>Can read or update a basic set of file attributes</td></tr>
 * <tr><th scope="row">
 *     <span style="padding-left:3em">
 *     <i>{@link java.nio.file.attribute.PosixFileAttributeView}</i></span></th>
 *     <td>Can read or update POSIX defined file attributes</td></tr>
 * <tr><th scope="row">
 *     <span style="padding-left:3em">
 *     <i>{@link java.nio.file.attribute.DosFileAttributeView}</i></span></th>
 *     <td>Can read or update FAT file attributes</td></tr>
 * <tr><th scope="row">
 *     <span style="padding-left:2em">
 *     <i>{@link java.nio.file.attribute.FileOwnerAttributeView}</i></span></th>
 *     <td>Can read or update the owner of a file</td></tr>
 * <tr><th scope="row">
 *     <span style="padding-left:3em">
 *     <i>{@link java.nio.file.attribute.AclFileAttributeView}</i></span></th>
 *     <td>Can read or update Access Control Lists</td></tr>
 * <tr><th scope="row">
 *     <span style="padding-left:2em">
 *     <i>{@link java.nio.file.attribute.UserDefinedFileAttributeView}</i></span></th>
 *     <td>Can read or update user-defined file attributes</td></tr>
 * <tr><th scope="row">
 *     <span style="padding-left:1em"><i>{@link java.nio.file.attribute.FileStoreAttributeView}</i></span></th>
 *     <td>Can read or update file system attributes</td></tr>
 * </tbody>
 * </table>
 *
 * <p> An attribute view provides a read-only or updatable view of the non-opaque
 * values, or <em>metadata</em>, associated with objects in a file system.
 * The {@link java.nio.file.attribute.FileAttributeView} interface is
 * extended by several other interfaces that provide views to specific sets of file
 * attributes. {@code FileAttributeViews} are selected by invoking the {@link
 * java.nio.file.Files#getFileAttributeView} method with a
 * <em>type-token</em> to identify the required view. Views can also be identified
 * by name. The {@link java.nio.file.attribute.FileStoreAttributeView} interface
 * provides access to file store attributes. A {@code FileStoreAttributeView} of
 * a given type is obtained by invoking the {@link
 * java.nio.file.FileStore#getFileStoreAttributeView} method.
 *
 * <p> The {@link java.nio.file.attribute.BasicFileAttributeView}
 * class defines methods to read and update a <em>basic</em> set of file
 * attributes that are common to many file systems.
 *
 * <p> The {@link java.nio.file.attribute.PosixFileAttributeView}
 * interface extends {@code BasicFileAttributeView} by defining methods
 * to access the file attributes commonly used by file systems and operating systems
 * that implement the Portable Operating System Interface (POSIX) family of
 * standards.
 *
 * <p> The {@link java.nio.file.attribute.DosFileAttributeView}
 * class extends {@code BasicFileAttributeView} by defining methods to
 * access the legacy "DOS" file attributes supported on file systems such as File
 * Allocation Tabl (FAT), commonly used in consumer devices.
 *
 * <p> The {@link java.nio.file.attribute.AclFileAttributeView}
 * class defines methods to read and write the Access Control List (ACL)
 * file attribute. The ACL model used by this file attribute view is based
 * on the model defined by <a href="http://www.ietf.org/rfc/rfc3530.txt">
 * <i>RFC&nbsp;3530: Network File System (NFS) version 4 Protocol</i></a>.
 *
 * <p> In addition to attribute views, this package also defines classes and
 * interfaces that are used when accessing attributes:
 *
 * <ul>
 *
 *   <li> The {@link java.nio.file.attribute.UserPrincipal} and
 *   {@link java.nio.file.attribute.GroupPrincipal} interfaces represent an
 *   identity or group identity. </li>
 *
 *   <li> The {@link java.nio.file.attribute.UserPrincipalLookupService}
 *   interface defines methods to lookup user or group principals. </li>
 *
 *   <li> The {@link java.nio.file.attribute.FileAttribute} interface
 *   represents the value of an attribute for cases where the attribute value is
 *   required to be set atomically when creating an object in the file system. </li>
 *
 * </ul>
 *
 *
 * <p> Unless otherwise noted, passing a {@code null} argument to a constructor
 * or method in any class or interface in this package will cause a {@link
 * java.lang.NullPointerException NullPointerException} to be thrown.
 *
 * @since 1.7
 */

package java.nio.file.attribute;