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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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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>&nbsp;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>&nbsp;&nbsp;{@link java.nio.ByteBuffer}</tt></td>
 *       <td>Get/put, compact, views; allocate,&nbsp;wrap</td></tr>
 *   <tr><td valign=top><tt>&nbsp;&nbsp;&nbsp;&nbsp;{@link java.nio.MappedByteBuffer}&nbsp;&nbsp;</tt></td>
 *       <td>A byte buffer mapped to a file</td></tr>
 *   <tr><td valign=top><tt>&nbsp;&nbsp;{@link java.nio.CharBuffer}</tt></td>
 *       <td>Get/put, compact; allocate,&nbsp;wrap</td></tr>
 *   <tr><td valign=top><tt>&nbsp;&nbsp;{@link java.nio.DoubleBuffer}</tt></td>
 *       <td>&nbsp;&nbsp;&nbsp;&nbsp;'&nbsp;'</td></tr>
 *   <tr><td valign=top><tt>&nbsp;&nbsp;{@link java.nio.FloatBuffer}</tt></td>
 *       <td>&nbsp;&nbsp;&nbsp;&nbsp;'&nbsp;'</td></tr>
 *   <tr><td valign=top><tt>&nbsp;&nbsp;{@link java.nio.IntBuffer}</tt></td>
 *       <td>&nbsp;&nbsp;&nbsp;&nbsp;'&nbsp;'</td></tr>
 *   <tr><td valign=top><tt>&nbsp;&nbsp;{@link java.nio.LongBuffer}</tt></td>
 *       <td>&nbsp;&nbsp;&nbsp;&nbsp;'&nbsp;'</td></tr>
 *   <tr><td valign=top><tt>&nbsp;&nbsp;{@link java.nio.ShortBuffer}</tt></td>
 *       <td>&nbsp;&nbsp;&nbsp;&nbsp;'&nbsp;'</td></tr>
 *   <tr><td valign=top><tt>{@link java.nio.ByteOrder}</tt></td>
 *       <td>Typesafe enumeration for&nbsp;byte&nbsp;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;
