| /* | |
| * Copyright (c) 2000, 2004, 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 | |
| * under the terms of the GNU General Public License version 2 only, as | |
| * published by the Free Software Foundation. Oracle designates this | |
| * 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 | |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| * 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 | |
| * 2 along with this work; if not, write to the Free Software Foundation, | |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| * | |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| * or visit www.oracle.com if you need additional information or have any | |
| * questions. | |
| */ | |
| /** | |
| * 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> | |
| * | |
| * </ul> | |
| * | |
| * <p> The <tt>java.nio</tt> package defines the buffer classes, which are used | |
| * throughout the NIO APIs. The charset API is defined in the {@link | |
| * java.nio.charset} package, and the channel and selector APIs are defined in the | |
| * {@link java.nio.channels} package. Each of these subpackages has its own | |
| * service-provider (SPI) subpackage, the contents of which can be used to extend | |
| * the platform's default implementations or to construct alternative | |
| * implementations. | |
| * | |
| * | |
| * <a name="buffers"> | |
| * | |
| * <blockquote><table cellspacing=1 cellpadding=0 summary="Description of the various buffers"> | |
| * <tr><th><p align="left">Buffers</p></th><th><p align="left">Description</p></th></tr> | |
| * <tr><td valign=top><tt>{@link java.nio.Buffer}</tt></td> | |
| * <td>Position, limit, and capacity; | |
| * <br>clear, flip, rewind, and mark/reset</td></tr> | |
| * <tr><td valign=top><tt> {@link java.nio.ByteBuffer}</tt></td> | |
| * <td>Get/put, compact, views; allocate, wrap</td></tr> | |
| * <tr><td valign=top><tt> {@link java.nio.MappedByteBuffer} </tt></td> | |
| * <td>A byte buffer mapped to a file</td></tr> | |
| * <tr><td valign=top><tt> {@link java.nio.CharBuffer}</tt></td> | |
| * <td>Get/put, compact; allocate, wrap</td></tr> | |
| * <tr><td valign=top><tt> {@link java.nio.DoubleBuffer}</tt></td> | |
| * <td> ' '</td></tr> | |
| * <tr><td valign=top><tt> {@link java.nio.FloatBuffer}</tt></td> | |
| * <td> ' '</td></tr> | |
| * <tr><td valign=top><tt> {@link java.nio.IntBuffer}</tt></td> | |
| * <td> ' '</td></tr> | |
| * <tr><td valign=top><tt> {@link java.nio.LongBuffer}</tt></td> | |
| * <td> ' '</td></tr> | |
| * <tr><td valign=top><tt> {@link java.nio.ShortBuffer}</tt></td> | |
| * <td> ' '</td></tr> | |
| * <tr><td valign=top><tt>{@link java.nio.ByteOrder}</tt></td> | |
| * <td>Typesafe enumeration for byte orders</td></tr> | |
| * </table></blockquote> | |
| * | |
| * <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 </code><i>mapping</i><code>} 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">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 <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 | |
| */ | |
| package java.nio; |