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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* 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).
*
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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>
*
* </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;