| author | yan |
| Mon, 18 Nov 2013 17:00:23 +0400 | |
| changeset 21801 | b8a5ff5f0c2a |
| parent 5506 | 202f599c92aa |
| child 23010 | 6dadb192ad81 |
| permissions | -rw-r--r-- |
| 2 | 1 |
<!-- |
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Copyright (c) 2000, 2004, Oracle and/or its affiliates. All rights reserved. |
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DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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This code is free software; you can redistribute it and/or modify it |
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under the terms of the GNU General Public License version 2 only, as |
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published by the Free Software Foundation. Oracle designates this |
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particular file as subject to the "Classpath" exception as provided |
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by Oracle in the LICENSE file that accompanied this code. |
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This code is distributed in the hope that it will be useful, but WITHOUT |
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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version 2 for more details (a copy is included in the LICENSE file that |
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accompanied this code). |
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You should have received a copy of the GNU General Public License version |
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2 along with this work; if not, write to the Free Software Foundation, |
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Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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or visit www.oracle.com if you need additional information or have any |
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--> |
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<!doctype html public "-//IETF//DTD HTML//EN"> |
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<html> |
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<body bgcolor="white"> |
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Defines buffers, which are containers for data, and provides an overview of the |
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other NIO packages. |
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<p> The central abstractions of the NIO APIs are: </p> |
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<ul> |
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<li><p> <a href="#buffers"><i>Buffers</i></a>, which are containers for data; |
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</p></li> |
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<li><p> <a href="charset/package-summary.html"><i>Charsets</i></a> and their |
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associated <i>decoders</i> and <i>encoders</i>, <br> which translate between |
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bytes and Unicode characters; </p></li> |
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<li><p> <a href="channels/package-summary.html"><i>Channels</i></a> of |
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various types, which represent connections <br> to entities capable of |
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performing I/O operations; and </p></li> |
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<li><p> <i>Selectors</i> and <i>selection keys</i>, which together with <br> |
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<i>selectable channels</i> define a <a |
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href="channels/package-summary.html#multiplex">multiplexed, non-blocking <br> |
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I/O</a> facility. </p></li> |
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</ul> |
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<p> The <tt>java.nio</tt> package defines the buffer classes, which are used |
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throughout the NIO APIs. The charset API is defined in the {@link
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java.nio.charset} package, and the channel and selector APIs are defined in the |
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{@link java.nio.channels} package. Each of these subpackages has its own
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service-provider (SPI) subpackage, the contents of which can be used to extend |
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the platform's default implementations or to construct alternative |
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implementations. |
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b8a5ff5f0c2a
8028049: Tidy warnings cleanup for packages java.nio/java.io
yan
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changeset
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<a name="buffers"> </a> |
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<blockquote><table cellspacing=1 cellpadding=0 summary="Description of the various buffers"> |
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<tr><th><p align="left">Buffers</p></th><th><p align="left">Description</p></th></tr> |
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<tr><td valign=top><tt>{@link java.nio.Buffer}</tt></td>
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<td>Position, limit, and capacity; |
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<br>clear, flip, rewind, and mark/reset</td></tr> |
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<tr><td valign=top><tt> {@link java.nio.ByteBuffer}</tt></td>
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<td>Get/put, compact, views; allocate, wrap</td></tr> |
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<tr><td valign=top><tt> {@link java.nio.MappedByteBuffer} </tt></td>
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<td>A byte buffer mapped to a file</td></tr> |
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<tr><td valign=top><tt> {@link java.nio.CharBuffer}</tt></td>
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<td>Get/put, compact; allocate, wrap</td></tr> |
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<tr><td valign=top><tt> {@link java.nio.DoubleBuffer}</tt></td>
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<td> ' '</td></tr> |
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<tr><td valign=top><tt> {@link java.nio.FloatBuffer}</tt></td>
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<td> ' '</td></tr> |
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<tr><td valign=top><tt> {@link java.nio.IntBuffer}</tt></td>
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<td> ' '</td></tr> |
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<tr><td valign=top><tt> {@link java.nio.LongBuffer}</tt></td>
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<td> ' '</td></tr> |
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<tr><td valign=top><tt> {@link java.nio.ShortBuffer}</tt></td>
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<td> ' '</td></tr> |
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<tr><td valign=top><tt>{@link java.nio.ByteOrder}</tt></td>
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<td>Typesafe enumeration for byte orders</td></tr> |
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</table></blockquote> |
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<p> A <i>buffer</i> is a container for a fixed amount of data of a specific |
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primitive type. In addition to its content a buffer has a <i>position</i>, |
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which is the index of the next element to be read or written, and a |
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<i>limit</i>, which is the index of the first element that should not be read |
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or written. The base {@link java.nio.Buffer} class defines these properties as
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well as methods for <i>clearing</i>, <i>flipping</i>, and <i>rewinding</i>, for |
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<i>marking</i> the current position, and for <i>resetting</i> the position to |
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the previous mark. |
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<p> There is a buffer class for each non-boolean primitive type. Each class |
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defines a family of <i>get</i> and <i>put</i> methods for moving data out of |
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and in to a buffer, methods for <i>compacting</i>, <i>duplicating</i>, and |
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<i>slicing</i> a buffer, and static methods for <i>allocating</i> a new buffer |
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as well as for <i>wrapping</i> an existing array into a buffer. |
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<p> Byte buffers are distinguished in that they can be used as the sources and |
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targets of I/O operations. They also support several features not found in the |
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other buffer classes: |
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<ul> |
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<li><p> A byte buffer can be allocated as a <a href="ByteBuffer.html#direct"> |
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<i>direct</i></a> buffer, in which case the Java virtual machine will make a |
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best effort to perform native I/O operations directly upon it. </p></li> |
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<li><p> A byte buffer can be created by {@link
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21801
b8a5ff5f0c2a
8028049: Tidy warnings cleanup for packages java.nio/java.io
yan
parents:
5506
diff
changeset
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java.nio.channels.FileChannel#map <i>mapping</i>} a region of a |
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file directly into memory, in which case a few additional file-related |
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operations defined in the {@link java.nio.MappedByteBuffer} class are
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available. </p></li> |
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<li><p> A byte buffer provides access to its content as either a heterogeneous |
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or homogeneous sequence of <a href="ByteBuffer.html#bin">binary data</i></a> |
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of any non-boolean primitive type, in either big-endian or little-endian <a |
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href="ByteOrder.html">byte order</a>. </p></li> |
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</ul> |
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<p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor |
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or method in any class or interface in this package will cause a {@link
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java.lang.NullPointerException NullPointerException} to be thrown. |
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@since 1.4 |
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@author Mark Reinhold |
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@author JSR-51 Expert Group |
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</body> |
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</html> |