| /* | |
| * Copyright (c) 2000, 2022, Oracle and/or its affiliates. All rights reserved. | |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| * | |
| * This code is free software; you can redistribute it and/or modify it | |
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| * particular file as subject to the "Classpath" exception as provided | |
| * by Oracle in the LICENSE file that accompanied this code. | |
| * | |
| * This code is distributed in the hope that it will be useful, but WITHOUT | |
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| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| * version 2 for more details (a copy is included in the LICENSE file that | |
| * accompanied this code). | |
| * | |
| * You should have received a copy of the GNU General Public License version | |
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| * | |
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| */ | |
| /** | |
| * Defines buffers, which are containers for data, and provides an | |
| * overview of the other NIO packages. | |
| * | |
| * | |
| * <p> The central abstractions of the NIO APIs are: </p> | |
| * | |
| * <ul> | |
| * | |
| * <li><p> <a href="#buffers"><i>Buffers</i></a>, which are containers for data; | |
| * </p></li> | |
| * | |
| * <li><p> <a | |
| * href="charset/package-summary.html"><i>Charsets</i></a> and their | |
| * associated <i>decoders</i> and <i>encoders</i>, <br> which | |
| * translate between bytes and Unicode characters; </p></li> | |
| * | |
| * <li><p> <a | |
| * href="channels/package-summary.html"><i>Channels</i></a> of | |
| * various types, which represent connections <br> to entities | |
| * capable of performing I/O operations; and </p></li> | |
| * | |
| * <li><p> <i>Selectors</i> and <i>selection keys</i>, which | |
| * together with <br> <i>selectable channels</i> define a <a | |
| * href="channels/package-summary.html#multiplex">multiplexed, | |
| * non-blocking <br> I/O</a> facility. </p></li> | |
| * | |
| * <li><p> <a | |
| * href="file/Path.html"><i>Path</i></a>, | |
| * which together with the <a href="file/Files.html"><i>Files</i></a> | |
| * class provides access to files. </p></li> | |
| * | |
| * </ul> | |
| * | |
| * <p> The {@code java.nio} package defines the buffer classes, which | |
| * are used throughout the NIO APIs. The charset API is defined in | |
| * the {@link java.nio.charset} package, the channel and selector APIs | |
| * in the {@link java.nio.channels} package, and the files and path APIs | |
| * in the {@link java.nio.file} package. Each of these subpackages has | |
| * its own service-provider interface (SPI) subpackage, the contents of | |
| * which can be used to extend the platform's default implementations or | |
| * to construct alternative implementations. | |
| * | |
| * <a id="buffers"> </a> | |
| * | |
| * <table class="striped" style="margin-left:2em; text-align:left"> | |
| * <caption style="display:none">Description of the various buffers</caption> | |
| * <thead> | |
| * <tr><th scope="col">Buffers</th> | |
| * <th scope="col">Description</th></tr> | |
| * </thead> | |
| * <tbody> | |
| * <tr><th scope="row">{@link java.nio.Buffer}</th> | |
| * <td>Position, limit, and capacity; | |
| * clear, flip, rewind, and mark/reset</td></tr> | |
| * <tr><th scope="row"> | |
| * <span style="padding-left:1em">{@link java.nio.ByteBuffer}</span></th> | |
| * <td>Get/put, compact, views; allocate, wrap</td></tr> | |
| * <tr><th scope="row"> | |
| * <span style="padding-left:2em">{@link java.nio.MappedByteBuffer}</span></th> | |
| * <td>A byte buffer mapped to a file</td></tr> | |
| * <tr><th scope="row"> | |
| * <span style="padding-left:1em">{@link java.nio.CharBuffer}</span></th> | |
| * <td>Get/put, compact; allocate, wrap</td></tr> | |
| * <tr><th scope="row"> | |
| * <span style="padding-left:1em">{@link java.nio.DoubleBuffer}</span></th> | |
| * <td>Get/put, compact; allocate, wrap</td></tr> | |
| * <tr><th scope="row"> | |
| * <span style="padding-left:1em">{@link java.nio.FloatBuffer}</span></th> | |
| * <td>Get/put, compact; allocate, wrap</td></tr> | |
| * <tr><th scope="row"> | |
| * <span style="padding-left:1em">{@link java.nio.IntBuffer}</span></th> | |
| * <td>Get/put, compact; allocate, wrap</td></tr> | |
| * <tr><th scope="row"> | |
| * <span style="padding-left:1em">{@link java.nio.LongBuffer}</span></th> | |
| * <td>Get/put, compact; allocate, wrap</td></tr> | |
| * <tr><th scope="row"> | |
| * <span style="padding-left:1em">{@link java.nio.ShortBuffer}</span></th> | |
| * <td>Get/put, compact; allocate, wrap</td></tr> | |
| * <tr><th scope="row">{@link java.nio.ByteOrder}</th> | |
| * <td>Typesafe enumeration for byte orders</td></tr> | |
| * </tbody> | |
| * </table> | |
| * | |
| * <p> A <i>buffer</i> is a container for a fixed amount of data of a | |
| * specific primitive type. In addition to its content a buffer has a | |
| * <i>position</i>, which is the index of the next element to be read | |
| * or written, and a <i>limit</i>, which is the index of the first | |
| * element that should not be read or written. The base {@link | |
| * java.nio.Buffer} class defines these properties as well as methods | |
| * for <i>clearing</i>, <i>flipping</i>, and <i>rewinding</i>, for | |
| * <i>marking</i> the current position, and for <i>resetting</i> the | |
| * position to the previous mark. | |
| * | |
| * <p> There is a buffer class for each non-boolean primitive type. | |
| * Each class defines a family of <i>get</i> and <i>put</i> methods | |
| * for moving data out of and in to a buffer, methods for | |
| * <i>compacting</i>, <i>duplicating</i>, and <i>slicing</i> a buffer, | |
| * and static methods for <i>allocating</i> a new buffer as well as | |
| * for <i>wrapping</i> an existing array into a buffer. | |
| * | |
| * <p> Byte buffers are distinguished in that they can be used as the | |
| * sources and targets of I/O operations. They also support several | |
| * features not found in the other buffer classes: | |
| * | |
| * <ul> | |
| * | |
| * <li><p> A byte buffer can be allocated as a <a | |
| * href="ByteBuffer.html#direct"> <i>direct</i></a> buffer, in which | |
| * case the Java virtual machine will make a best effort to perform | |
| * native I/O operations directly upon it. </p></li> | |
| * | |
| * <li><p> A byte buffer can be created by {@link | |
| * java.nio.channels.FileChannel#map <i>mapping</i>} a region of a | |
| * file directly into memory, in which case a few additional | |
| * file-related operations defined in the {@link | |
| * java.nio.MappedByteBuffer} class are available. </p></li> | |
| * | |
| * <li><p> A byte buffer provides access to its content as either a | |
| * heterogeneous or homogeneous sequence of <a | |
| * href="ByteBuffer.html#bin"><i>binary data</i></a> of any | |
| * non-boolean primitive type, in either big-endian or little-endian | |
| * <a href="ByteOrder.html">byte order</a>. </p></li> | |
| * | |
| * </ul> | |
| * | |
| * <p> Unless otherwise noted, passing a {@code null} 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 | |
| */ | |
| package java.nio; |