--- a/jdk/src/share/classes/java/nio/channels/package.html Sun Aug 31 18:32:59 2008 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,222 +0,0 @@
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-<!doctype html public "-//IETF//DTD HTML//EN">
-<html>
-<body bgcolor="white">
-
-Defines channels, which represent connections to entities that are capable of
-performing I/O operations, such as files and sockets; defines selectors, for
-multiplexed, non-blocking I/O operations.
-
-
-<a name="channels">
-
-<blockquote><table cellspacing=1 cellpadding=0 summary="Lists channels and their descriptions">
- <tr><th><p align="left">Channels</p></th><th><p align="left">Description</p></th></tr>
- <tr><td valign=top><tt><i>{@link java.nio.channels.Channel}</i></tt></td>
- <td>A nexus for I/O operations</td></tr>
- <tr><td valign=top><tt> <i>{@link java.nio.channels.ReadableByteChannel}</i></tt></td>
- <td>Can read into a buffer</td></tr>
- <tr><td valign=top><tt> <i>{@link java.nio.channels.ScatteringByteChannel} </i></tt></td>
- <td>Can read into a sequence of buffers</td></tr>
- <tr><td valign=top><tt> <i>{@link java.nio.channels.WritableByteChannel}</i></tt></td>
- <td>Can write from a buffer</td></tr>
- <tr><td valign=top><tt> <i>{@link java.nio.channels.GatheringByteChannel}</i></tt></td>
- <td>Can write from a sequence of buffers</td></tr>
- <tr><td valign=top><tt> <i>{@link java.nio.channels.ByteChannel}</i></tt></td>
- <td>Can read/write to/from a buffer</td></tr>
- <tr><td valign=top><tt>{@link java.nio.channels.Channels}</tt></td>
- <td>Utility methods for channel/stream interoperation</td></tr>
-</table></blockquote>
-
-<p> A <i>channel</i> represents an open connection to an entity such as a
-hardware device, a file, a network socket, or a program component that is
-capable of performing one or more distinct I/O operations, for example reading
-or writing. As specified in the {@link java.nio.channels.Channel} interface,
-channels are either open or closed, and they are both <i>asynchronously
-closeable</i> and <i>interruptible</i>.
-
-<p> The {@link java.nio.channels.Channel} interface is extended by several
-other interfaces, each of which specifies a new I/O operation.
-
-<p> The {@link java.nio.channels.ReadableByteChannel} interface specifies a
-{@link java.nio.channels.ReadableByteChannel#read read} method that reads bytes
-from the channel into a buffer; similarly, the {@link
-java.nio.channels.WritableByteChannel} interface specifies a {@link
-java.nio.channels.WritableByteChannel#write write} method that writes bytes
-from a buffer to the channel. The {@link java.nio.channels.ByteChannel}
-interface unifies these two interfaces for the common case of channels that can
-both read and write bytes.
-
-<p> The {@link java.nio.channels.ScatteringByteChannel} and {@link
-java.nio.channels.GatheringByteChannel} interfaces extend the {@link
-java.nio.channels.ReadableByteChannel} and {@link
-java.nio.channels.WritableByteChannel} interfaces, respectively, adding {@link
-java.nio.channels.ScatteringByteChannel#read read} and {@link
-java.nio.channels.GatheringByteChannel#write write} methods that take a
-sequence of buffers rather than a single buffer.
-
-<p> The {@link java.nio.channels.Channels} utility class defines static methods
-that support the interoperation of the stream classes of the <tt>{@link
-java.io}</tt> package with the channel classes of this package. An appropriate
-channel can be constructed from an {@link java.io.InputStream} or an {@link
-java.io.OutputStream}, and conversely an {@link java.io.InputStream} or an
-{@link java.io.OutputStream} can be constructed from a channel. A {@link
-java.io.Reader} can be constructed that uses a given charset to decode bytes
-from a given readable byte channel, and conversely a {@link java.io.Writer} can
-be constructed that uses a given charset to encode characters into bytes and
-write them to a given writable byte channel.
-
-
-<blockquote><table cellspacing=1 cellpadding=0 summary="Lists file channels and their descriptions">
-<tr><th><p align="left">File channels</p></th><th><p align="left">Description</p></th></tr>
- <tr><td valign=top><tt>{@link java.nio.channels.FileChannel}</tt></td>
- <td>Reads, writes, maps, and manipulates files</td></tr>
- <tr><td valign=top><tt>{@link java.nio.channels.FileLock}</tt></td>
- <td>A lock on a (region of a) file</td></tr>
- <tr><td valign=top><tt>{@link java.nio.MappedByteBuffer} </tt></td>
- <td>A direct byte buffer mapped to a region of a file</td></tr>
-</table></blockquote>
-
-<p> The {@link java.nio.channels.FileChannel} class supports the usual
-operations of reading bytes from, and writing bytes to, a channel connected to
-a file, as well as those of querying and modifying the current file position
-and truncating the file to a specific size. It defines methods for acquiring
-locks on the whole file or on a specific region of a file; these methods return
-instances of the {@link java.nio.channels.FileLock} class. Finally, it defines
-methods for forcing updates to the file to be written to the storage device that
-contains it, for efficiently transferring bytes between the file and other
-channels, and for mapping a region of the file directly into memory. This last
-operation creates an instance of the {@link java.nio.MappedByteBuffer}
-class, which extends the {@link java.nio.ByteBuffer} class with several
-file-related operations.
-
-<p> A <tt>getChannel</tt> method has been added to each of the {@link
-java.io.FileInputStream#getChannel FileInputStream}, {@link
-java.io.FileOutputStream#getChannel FileOutputStream}, and {@link
-java.io.RandomAccessFile#getChannel RandomAccessFile} classes of the <tt>{@link
-java.io java.io}</tt> package. Invoking this method upon an instance of one of
-these classes will return a file channel connected to the underlying file.
-
-
-<a name="multiplex">
-
-<blockquote><table cellspacing=1 cellpadding=0 summary="Lists multiplexed, non-blocking channels and their descriptions">
- <tr><th><p align="left">Multiplexed, non-blocking I/O</p></th><th><p align="left">Description</p></th></tr>
- <tr><td valign=top><tt>{@link java.nio.channels.SelectableChannel}</tt></td>
- <td>A channel that can be multiplexed</td></tr>
- <tr><td valign=top><tt> {@link java.nio.channels.DatagramChannel}</tt></td>
- <td>A channel for a {@link java.net.DatagramSocket java.net.DatagramSocket}</td></tr>
- <tr><td valign=top><tt> {@link java.nio.channels.Pipe.SinkChannel}</tt></td>
- <td>The write end of a pipe</td></tr>
- <tr><td valign=top><tt> {@link java.nio.channels.Pipe.SourceChannel}</tt></td>
- <td>The read end of a pipe</td></tr>
- <tr><td valign=top><tt> {@link java.nio.channels.ServerSocketChannel} </tt></td>
- <td>A channel for a {@link java.net.ServerSocket java.net.ServerSocket}</td></tr>
- <tr><td valign=top><tt> {@link java.nio.channels.SocketChannel}</tt></td>
- <td>A channel for a {@link java.net.Socket java.net.Socket}</td></tr>
- <tr><td valign=top><tt>{@link java.nio.channels.Selector}</tt></td>
- <td>A multiplexor of selectable channels</td></tr>
- <tr><td valign=top><tt>{@link java.nio.channels.SelectionKey}</tt></td>
- <td>A token representing the registration <br> of a channel
- with a selector</td></tr>
- <tr><td valign=top><tt>{@link java.nio.channels.Pipe}</tt></td>
- <td>Two channels that form a unidirectional pipe</td></tr>
-</table></blockquote>
-
-<p> Multiplexed, non-blocking I/O, which is much more scalable than
-thread-oriented, blocking I/O, is provided by <i>selectors</i>, <i>selectable
-channels</i>, and <i>selection keys</i>.
-
-<p> A <a href="Selector.html"><i>selector</i></a> is a multiplexor of <a
-href="SelectableChannel.html"><i>selectable channels</i></a>, which in turn are
-a special type of channel that can be put into <a
-href="SelectableChannel.html#bm"><i>non-blocking mode</i></a>. To perform
-multiplexed I/O operations, one or more selectable channels are first created,
-put into non-blocking mode, and {@link
-java.nio.channels.SelectableChannel#register </code><i>registered</i><code>}
-with a selector. Registering a channel specifies the set of I/O operations
-that will be tested for readiness by the selector, and returns a <a
-href="SelectionKey.html"><i>selection key</i></a> that represents the
-registration.
-
-<p> Once some channels have been registered with a selector, a <a
-href="Selector.html#selop"><i>selection operation</i></a> can be performed in
-order to discover which channels, if any, have become ready to perform one or
-more of the operations in which interest was previously declared. If a channel
-is ready then the key returned when it was registered will be added to the
-selector's <i>selected-key set</i>. The key set, and the keys within it, can
-be examined in order to determine the operations for which each channel is
-ready. From each key one can retrieve the corresponding channel in order to
-perform whatever I/O operations are required.
-
-<p> That a selection key indicates that its channel is ready for some operation
-is a hint, but not a guarantee, that such an operation can be performed by a
-thread without causing the thread to block. It is imperative that code that
-performs multiplexed I/O be written so as to ignore these hints when they prove
-to be incorrect.
-
-<p> This package defines selectable-channel classes corresponding to the {@link
-java.net.DatagramSocket}, {@link java.net.ServerSocket}, and {@link
-java.net.Socket} classes defined in the <tt>{@link java.net}</tt> package.
-Minor changes to these classes have been made in order to support sockets that
-are associated with channels. This package also defines a simple class that
-implements unidirectional pipes. In all cases, a new selectable channel is
-created by invoking the static <tt>open</tt> method of the corresponding class.
-If a channel needs an associated socket then a socket will be created as a side
-effect of this operation.
-
-<p> The implementation of selectors, selectable channels, and selection keys
-can be replaced by "plugging in" an alternative definition or instance of the
-{@link java.nio.channels.spi.SelectorProvider} class defined in the <tt>{@link
-java.nio.channels.spi}</tt> package. It is not expected that many developers
-will actually make use of this facility; it is provided primarily so that
-sophisticated users can take advantage of operating-system-specific
-I/O-multiplexing mechanisms when very high performance is required.
-
-<p> Much of the bookkeeping and synchronization required to implement the
-multiplexed-I/O abstractions is performed by the {@link
-java.nio.channels.spi.AbstractInterruptibleChannel}, {@link
-java.nio.channels.spi.AbstractSelectableChannel}, {@link
-java.nio.channels.spi.AbstractSelectionKey}, and {@link
-java.nio.channels.spi.AbstractSelector} classes in the <tt>{@link
-java.nio.channels.spi}</tt> package. When defining a custom selector provider,
-only the {@link java.nio.channels.spi.AbstractSelector} and {@link
-java.nio.channels.spi.AbstractSelectionKey} classes should be subclassed
-directly; custom channel classes should extend the appropriate {@link
-java.nio.channels.SelectableChannel} subclasses defined in this package.
-
-<p> Unless otherwise noted, passing a <tt>null</tt> 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 1.4
-@author Mark Reinhold
-@author JSR-51 Expert Group
-
-</body>
-</html>