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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 BasicFileAttributes interface. The file attributes are retrieved from the file system as a bulk
operation by invoking the readAttributes method. This class also defines the 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:
Supported attributes
Name
Type
"lastModifiedTime"
FileTime
"lastAccessTime"
FileTime
"creationTime"
FileTime
"size"
Long
"isRegularFile"
Boolean
"isDirectory"
Boolean
"isSymbolicLink"
Boolean
"isOther"
Boolean
"fileKey"
Object
The getAttribute method may be used to read any of these attributes as if by invoking the readAttributes() method.
The 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 setTimes method.
Since: 1.7
/**
* A file attribute view that provides a view of a <em>basic set</em> of file
* attributes common to many file systems. The basic set of file attributes
* consist of <em>mandatory</em> and <em>optional</em> file attributes as
* defined by the {@link BasicFileAttributes} interface.
* <p> The file attributes are retrieved from the file system as a <em>bulk
* operation</em> by invoking the {@link #readAttributes() readAttributes} method.
* This class also defines the {@link #setTimes setTimes} method to update the
* file's time attributes.
*
* <p> Where dynamic access to file attributes is required, the attributes
* supported by this attribute view have the following names and types:
* <blockquote>
* <table class="striped">
* <caption style="display:none">Supported attributes</caption>
* <thead>
* <tr>
* <th scope="col"> Name </th>
* <th scope="col"> Type </th>
* </tr>
* </thead>
* <tbody>
* <tr>
* <th scope="row"> "lastModifiedTime" </th>
* <td> {@link FileTime} </td>
* </tr>
* <tr>
* <th scope="row"> "lastAccessTime" </th>
* <td> {@link FileTime} </td>
* </tr>
* <tr>
* <th scope="row"> "creationTime" </th>
* <td> {@link FileTime} </td>
* </tr>
* <tr>
* <th scope="row"> "size" </th>
* <td> {@link Long} </td>
* </tr>
* <tr>
* <th scope="row"> "isRegularFile" </th>
* <td> {@link Boolean} </td>
* </tr>
* <tr>
* <th scope="row"> "isDirectory" </th>
* <td> {@link Boolean} </td>
* </tr>
* <tr>
* <th scope="row"> "isSymbolicLink" </th>
* <td> {@link Boolean} </td>
* </tr>
* <tr>
* <th scope="row"> "isOther" </th>
* <td> {@link Boolean} </td>
* </tr>
* <tr>
* <th scope="row"> "fileKey" </th>
* <td> {@link Object} </td>
* </tr>
* </tbody>
* </table>
* </blockquote>
*
* <p> 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.
*
* <p> 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 "basic". /**
* 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.
Throws: - IOException –
if an I/O error occurs
- SecurityException – In the case of the default provider, a security manager is installed, its
checkRead method is invoked to check read access to the file
Returns: the file attributes
/**
* Reads the basic file attributes as a bulk operation.
*
* <p> 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 IOException.
If any of the lastModifiedTime, lastAccessTime, or createTime parameters has the value 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 lastModifiedTime,
lastAccessTime and createTime parameters are null then this method has no effect.
Usage Example:
Suppose we want to change a file's last access time.
Path path = ...
FileTime time = ...
Files.getFileAttributeView(path, BasicFileAttributeView.class).setTimes(null, time, null);
Params: - lastModifiedTime – the new last modified time, or
null to not change the value - lastAccessTime – the last access time, or
null to not change the value - createTime – the file's create time, or
null to not change the value
Throws: - IOException –
if an I/O error occurs
- SecurityException – In the case of the default provider, a security manager is installed, its
checkWrite method is invoked to check write access to the file
See Also:
/**
* Updates any or all of the file's last modified time, last access time,
* and create time attributes.
*
* <p> 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}.
*
* <p> 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.
*
* <p> <b>Usage Example:</b>
* Suppose we want to change a file's last access time.
* <pre>
* Path path = ...
* FileTime time = ...
* Files.getFileAttributeView(path, BasicFileAttributeView.class).setTimes(null, time, null);
* </pre>
*
* @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;
}