Module java.base

Package java.nio.file.attribute

Interface BasicFileAttributeView

All Superinterfaces:

AttributeView, FileAttributeView

All Known Subinterfaces:

DosFileAttributeView, PosixFileAttributeView

public interface BasicFileAttributeView
extends FileAttributeView

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

Method Summary

Modifier and Type	Method	Description
String	name()	Returns the name of the attribute view.
BasicFileAttributes	readAttributes()	Reads the basic file attributes as a bulk operation.
void	setTimes(FileTime lastModifiedTime, FileTime lastAccessTime, FileTime createTime)	Updates any or all of the file's last modified time, last access time, and create time attributes.

Method Detail

name

String name()

Returns the name of the attribute view. Attribute views of this type have the name "basic".

Specified by:

name in interface AttributeView

Returns:

the name of the attribute view

readAttributes

BasicFileAttributes readAttributes()
                            throws IOException

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.

Returns:

the file attributes

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

setTimes

void setTimes(FileTime lastModifiedTime,
              FileTime lastAccessTime,
              FileTime createTime)
       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);
 

Parameters:

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:

Files.setLastModifiedTime(java.nio.file.Path, java.nio.file.attribute.FileTime)