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  25 
  26 /**
  27  * Interfaces and classes providing access to file and file system attributes.
  28  *
  29  * <blockquote><table class="borderless">
  30  *     <caption style="display:none">Attribute views</caption>
  31  * <tr><th style="text-align:left">Attribute views</th>
  32  *     <th style="text-align:left">Description</th></tr>
  33  * <tr><td><i>{@link java.nio.file.attribute.AttributeView}</i></td>
  34  *     <td>Can read or update non-opaque values associated with objects in a file system</td></tr>
  35  * <tr><td style="vertical-align:top">
  36  *     &nbsp;&nbsp;<i>{@link java.nio.file.attribute.FileAttributeView}</i></td>
  37  *     <td>Can read or update file attributes</td></tr>
  38  * <tr><td style="vertical-align:top">
  39  *     &nbsp;&nbsp;&nbsp;&nbsp;
  40  *     <i>{@link java.nio.file.attribute.BasicFileAttributeView}&nbsp;&nbsp;</i></td>
  41  *     <td>Can read or update a basic set of file attributes</td></tr>
  42  * <tr><td style="vertical-align:top">
  43  *     &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
  44  *     <i>{@link java.nio.file.attribute.PosixFileAttributeView}&nbsp;&nbsp;</i></td>
  45  *     <td>Can read or update POSIX defined file attributes</td></tr>
  46  * <tr><td style="vertical-align:top">
  47  *     &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
  48  *     <i>{@link java.nio.file.attribute.DosFileAttributeView}&nbsp;&nbsp;</i></td>
  49  *     <td>Can read or update FAT file attributes</td></tr>
  50  * <tr><td style="vertical-align:top">
  51  *     &nbsp;&nbsp;&nbsp;&nbsp;
  52  *     <i>{@link java.nio.file.attribute.FileOwnerAttributeView}&nbsp;&nbsp;</i></td>
  53  *     <td>Can read or update the owner of a file</td></tr>
  54  * <tr><td style="vertical-align:top">
  55  *     &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
  56  *     <i>{@link java.nio.file.attribute.AclFileAttributeView}&nbsp;&nbsp;</i></td>
  57  *     <td>Can read or update Access Control Lists</td></tr>
  58  * <tr><td style="vertical-align:top">
  59  *     &nbsp;&nbsp;&nbsp;&nbsp;
  60  *     <i>{@link java.nio.file.attribute.UserDefinedFileAttributeView}&nbsp;&nbsp;</i></td>
  61  *     <td>Can read or update user-defined file attributes</td></tr>
  62  * <tr><td style="vertical-align:top">
  63  *     &nbsp;&nbsp;<i>{@link java.nio.file.attribute.FileStoreAttributeView}</i></td>
  64  *     <td>Can read or update file system attributes</td></tr>
  65  * </table></blockquote>
  66  *
  67  * <p> An attribute view provides a read-only or updatable view of the non-opaque
  68  * values, or <em>metadata</em>, associated with objects in a file system.
  69  * The {@link java.nio.file.attribute.FileAttributeView} interface is
  70  * extended by several other interfaces that provide views to specific sets of file
  71  * attributes. {@code FileAttributeViews} are selected by invoking the {@link
  72  * java.nio.file.Files#getFileAttributeView} method with a
  73  * <em>type-token</em> to identify the required view. Views can also be identified
  74  * by name. The {@link java.nio.file.attribute.FileStoreAttributeView} interface
  75  * provides access to file store attributes. A {@code FileStoreAttributeView} of
  76  * a given type is obtained by invoking the {@link
  77  * java.nio.file.FileStore#getFileStoreAttributeView} method.
  78  *
  79  * <p> The {@link java.nio.file.attribute.BasicFileAttributeView}
  80  * class defines methods to read and update a <em>basic</em> set of file
  81  * attributes that are common to many file systems.
  82  *
  83  * <p> The {@link java.nio.file.attribute.PosixFileAttributeView}
  84  * interface extends {@code BasicFileAttributeView} by defining methods
  85  * to access the file attributes commonly used by file systems and operating systems
  86  * that implement the Portable Operating System Interface (POSIX) family of
  87  * standards.
  88  *
  89  * <p> The {@link java.nio.file.attribute.DosFileAttributeView}
  90  * class extends {@code BasicFileAttributeView} by defining methods to
  91  * access the legacy "DOS" file attributes supported on file systems such as File
  92  * Allocation Tabl (FAT), commonly used in consumer devices.
  93  *
  94  * <p> The {@link java.nio.file.attribute.AclFileAttributeView}
  95  * class defines methods to read and write the Access Control List (ACL)
  96  * file attribute. The ACL model used by this file attribute view is based
  97  * on the model defined by <a href="http://www.ietf.org/rfc/rfc3530.txt">
  98  * <i>RFC&nbsp;3530: Network File System (NFS) version 4 Protocol</i></a>.
  99  *
 100  * <p> In addition to attribute views, this package also defines classes and
 101  * interfaces that are used when accessing attributes:
 102  *
 103  * <ul>
 104  *
 105  *   <li> The {@link java.nio.file.attribute.UserPrincipal} and
 106  *   {@link java.nio.file.attribute.GroupPrincipal} interfaces represent an
 107  *   identity or group identity. </li>
 108  *
 109  *   <li> The {@link java.nio.file.attribute.UserPrincipalLookupService}
 110  *   interface defines methods to lookup user or group principals. </li>
 111  *
 112  *   <li> The {@link java.nio.file.attribute.FileAttribute} interface
 113  *   represents the value of an attribute for cases where the attribute value is
 114  *   required to be set atomically when creating an object in the file system. </li>
 115  *
 116  * </ul>
 117  *
 118  *
 119  * <p> Unless otherwise noted, passing a {@code null} argument to a constructor
 120  * or method in any class or interface in this package will cause a {@link
 121  * java.lang.NullPointerException NullPointerException} to be thrown.
 122  *
 123  * @since 1.7
 124  */
 125 
 126 package java.nio.file.attribute;