14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /**
27 * Defines interfaces and classes for the Java virtual machine to access files,
28 * file attributes, and file systems.
29 *
30 * <p> The java.nio.file package defines classes to access files and file
31 * systems. The API to access file and file system attributes is defined in the
32 * {@link java.nio.file.attribute} package. The {@link java.nio.file.spi}
33 * package is used by service provider implementors wishing to extend the
34 * platform default provider, or to construct other provider implementations.
35 *
36 * <a name="links"><h3>Symbolic Links</h3></a>
37 * Many operating systems and file systems support for <em>symbolic links</em>.
38 * A symbolic link is a special file that serves as a reference to another file.
39 * For the most part, symbolic links are transparent to applications and
40 * operations on symbolic links are automatically redirected to the <em>target</em>
41 * of the link. Exceptions to this are when a symbolic link is deleted or
42 * renamed/moved in which case the link is deleted or removed rather than the
43 * target of the link. This package includes support for symbolic links where
44 * implementations provide these semantics. File systems may support other types
45 * that are semantically close but support for these other types of links is
46 * not included in this package.
47 *
48 * <a name="interop"><h3>Interoperability</h3></a>
49 * The {@link java.io.File} class defines the {@link java.io.File#toPath
50 * toPath} method to construct a {@link java.nio.file.Path} by converting
51 * the abstract path represented by the {@code java.io.File} object. The resulting
52 * {@code Path} can be used to operate on the same file as the {@code File}
53 * object. The {@code Path} specification provides further information
54 * on the <a href="Path.html#interop">interoperability</a> between {@code Path}
55 * and {@code java.io.File} objects.
56 *
57 * <h3>Visibility</h3>
58 * The view of the files and file system provided by classes in this package are
59 * guaranteed to be consistent with other views provided by other instances in the
60 * same Java virtual machine. The view may or may not, however, be consistent with
61 * the view of the file system as seen by other concurrently running programs due
62 * to caching performed by the underlying operating system and delays induced by
63 * network-filesystem protocols. This is true regardless of the language in which
64 * these other programs are written, and whether they are running on the same machine
65 * or on some other machine. The exact nature of any such inconsistencies are
66 * system-dependent and are therefore unspecified.
67 *
68 * <a name="integrity"><h3>Synchronized I/O File Integrity</h3></a>
69 * The {@link java.nio.file.StandardOpenOption#SYNC SYNC} and {@link
70 * java.nio.file.StandardOpenOption#DSYNC DSYNC} options are used when opening a file
71 * to require that updates to the file are written synchronously to the underlying
72 * storage device. In the case of the default provider, and the file resides on
73 * a local storage device, and the {@link java.nio.channels.SeekableByteChannel
74 * seekable} channel is connected to a file that was opened with one of these
75 * options, then an invocation of the {@link
76 * java.nio.channels.WritableByteChannel#write(java.nio.ByteBuffer) write}
77 * method is only guaranteed to return when all changes made to the file
78 * by that invocation have been written to the device. These options are useful
79 * for ensuring that critical information is not lost in the event of a system
80 * crash. If the file does not reside on a local device then no such guarantee
81 * is made. Whether this guarantee is possible with other {@link
82 * java.nio.file.spi.FileSystemProvider provider} implementations is provider
83 * specific.
84 *
85 * <h3>General Exceptions</h3>
86 * Unless otherwise noted, passing a {@code null} argument to a constructor
87 * or method of any class or interface in this package will cause a {@link
88 * java.lang.NullPointerException NullPointerException} to be thrown. Additionally,
89 * invoking a method with a collection containing a {@code null} element will
90 * cause a {@code NullPointerException}, unless otherwise specified.
91 *
92 * <p> Unless otherwise noted, methods that attempt to access the file system
93 * will throw {@link java.nio.file.ClosedFileSystemException} when invoked on
94 * objects associated with a {@link java.nio.file.FileSystem} that has been
95 * {@link java.nio.file.FileSystem#close closed}. Additionally, any methods
96 * that attempt write access to a file system will throw {@link
97 * java.nio.file.ReadOnlyFileSystemException} when invoked on an object associated
98 * with a {@link java.nio.file.FileSystem} that only provides read-only access.
99 *
100 * <p> Unless otherwise noted, invoking a method of any class or interface in
101 * this package created by one {@link java.nio.file.spi.FileSystemProvider
102 * provider} with a parameter that is an object created by another provider,
103 * will throw {@link java.nio.file.ProviderMismatchException}.
104 *
105 * <h3>Optional Specific Exceptions</h3>
106 * Most of the methods defined by classes in this package that access the
107 * file system specify that {@link java.io.IOException} be thrown when an I/O
108 * error occurs. In some cases, these methods define specific I/O exceptions
109 * for common cases. These exceptions, noted as <i>optional specific exceptions</i>,
110 * are thrown by the implementation where it can detect the specific error.
111 * Where the specific error cannot be detected then the more general {@code
112 * IOException} is thrown.
113 *
114 * @since 1.7
115 */
116 package java.nio.file;
|
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /**
27 * Defines interfaces and classes for the Java virtual machine to access files,
28 * file attributes, and file systems.
29 *
30 * <p> The java.nio.file package defines classes to access files and file
31 * systems. The API to access file and file system attributes is defined in the
32 * {@link java.nio.file.attribute} package. The {@link java.nio.file.spi}
33 * package is used by service provider implementors wishing to extend the
34 * platform default provider, or to construct other provider implementations. </p>
35 *
36 * <a name="links"><h3>Symbolic Links</h3></a>
37 * Many operating systems and file systems support for <em>symbolic links</em>.
38 * A symbolic link is a special file that serves as a reference to another file.
39 * For the most part, symbolic links are transparent to applications and
40 * operations on symbolic links are automatically redirected to the <em>target</em>
41 * of the link. Exceptions to this are when a symbolic link is deleted or
42 * renamed/moved in which case the link is deleted or removed rather than the
43 * target of the link. This package includes support for symbolic links where
44 * implementations provide these semantics. File systems may support other types
45 * that are semantically close but support for these other types of links is
46 * not included in this package. </p>
47 *
48 * <a name="interop"><h3>Interoperability</h3></a>
49 * The {@link java.io.File} class defines the {@link java.io.File#toPath
50 * toPath} method to construct a {@link java.nio.file.Path} by converting
51 * the abstract path represented by the {@code java.io.File} object. The resulting
52 * {@code Path} can be used to operate on the same file as the {@code File}
53 * object. The {@code Path} specification provides further information
54 * on the <a href="Path.html#interop">interoperability</a> between {@code Path}
55 * and {@code java.io.File} objects. </p>
56 *
57 * <h3>Visibility</h3>
58 * The view of the files and file system provided by classes in this package are
59 * guaranteed to be consistent with other views provided by other instances in the
60 * same Java virtual machine. The view may or may not, however, be consistent with
61 * the view of the file system as seen by other concurrently running programs due
62 * to caching performed by the underlying operating system and delays induced by
63 * network-filesystem protocols. This is true regardless of the language in which
64 * these other programs are written, and whether they are running on the same machine
65 * or on some other machine. The exact nature of any such inconsistencies are
66 * system-dependent and are therefore unspecified. </p>
67 *
68 * <a name="integrity"><h3>Synchronized I/O File Integrity</h3></a>
69 * The {@link java.nio.file.StandardOpenOption#SYNC SYNC} and {@link
70 * java.nio.file.StandardOpenOption#DSYNC DSYNC} options are used when opening a file
71 * to require that updates to the file are written synchronously to the underlying
72 * storage device. In the case of the default provider, and the file resides on
73 * a local storage device, and the {@link java.nio.channels.SeekableByteChannel
74 * seekable} channel is connected to a file that was opened with one of these
75 * options, then an invocation of the {@link
76 * java.nio.channels.WritableByteChannel#write(java.nio.ByteBuffer) write}
77 * method is only guaranteed to return when all changes made to the file
78 * by that invocation have been written to the device. These options are useful
79 * for ensuring that critical information is not lost in the event of a system
80 * crash. If the file does not reside on a local device then no such guarantee
81 * is made. Whether this guarantee is possible with other {@link
82 * java.nio.file.spi.FileSystemProvider provider} implementations is provider
83 * specific. </p>
84 *
85 * <h3>General Exceptions</h3>
86 * Unless otherwise noted, passing a {@code null} argument to a constructor
87 * or method of any class or interface in this package will cause a {@link
88 * java.lang.NullPointerException NullPointerException} to be thrown. Additionally,
89 * invoking a method with a collection containing a {@code null} element will
90 * cause a {@code NullPointerException}, unless otherwise specified. </p>
91 *
92 * <p> Unless otherwise noted, methods that attempt to access the file system
93 * will throw {@link java.nio.file.ClosedFileSystemException} when invoked on
94 * objects associated with a {@link java.nio.file.FileSystem} that has been
95 * {@link java.nio.file.FileSystem#close closed}. Additionally, any methods
96 * that attempt write access to a file system will throw {@link
97 * java.nio.file.ReadOnlyFileSystemException} when invoked on an object associated
98 * with a {@link java.nio.file.FileSystem} that only provides read-only
99 * access. </p>
100 *
101 * <p> Unless otherwise noted, invoking a method of any class or interface in
102 * this package created by one {@link java.nio.file.spi.FileSystemProvider
103 * provider} with a parameter that is an object created by another provider,
104 * will throw {@link java.nio.file.ProviderMismatchException}. </p>
105 *
106 * <h3>Optional Specific Exceptions</h3>
107 * Most of the methods defined by classes in this package that access the
108 * file system specify that {@link java.io.IOException} be thrown when an I/O
109 * error occurs. In some cases, these methods define specific I/O exceptions
110 * for common cases. These exceptions, noted as <i>optional specific exceptions</i>,
111 * are thrown by the implementation where it can detect the specific error.
112 * Where the specific error cannot be detected then the more general {@code
113 * IOException} is thrown.
114 *
115 * @since 1.7
116 */
117 package java.nio.file;
|