The central abstractions of the NIO APIs are:
- -Buffers, which are containers for data; -
Charsets and their
- associated decoders and encoders,
which translate between
- bytes and Unicode characters;
Channels of
- various types, which represent connections
to entities capable of
- performing I/O operations; and
Selectors and selection keys, which together with
- selectable channels define a multiplexed, non-blocking
- I/O facility.
The 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, 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. - - - - -
- --
- Buffers
Description
- {@link java.nio.Buffer} -Position, limit, and capacity; -
clear, flip, rewind, and mark/reset- {@link java.nio.ByteBuffer} -Get/put, compact, views; allocate, wrap - {@link java.nio.MappedByteBuffer} -A byte buffer mapped to a file - {@link java.nio.CharBuffer} -Get/put, compact; allocate, wrap - {@link java.nio.DoubleBuffer} -' ' - {@link java.nio.FloatBuffer} -' ' - {@link java.nio.IntBuffer} -' ' - {@link java.nio.LongBuffer} -' ' - {@link java.nio.ShortBuffer} -' ' - {@link java.nio.ByteOrder} -Typesafe enumeration for byte orders
A buffer is a container for a fixed amount of data of a specific -primitive type. In addition to its content a buffer has a position, -which is the index of the next element to be read or written, and a -limit, 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 clearing, flipping, and rewinding, for -marking the current position, and for resetting the position to -the previous mark. - -
There is a buffer class for each non-boolean primitive type. Each class -defines a family of get and put methods for moving data out of -and in to a buffer, methods for compacting, duplicating, and -slicing a buffer, and static methods for allocating a new buffer -as well as for wrapping an existing array into a buffer. - -
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: - -
A byte buffer can be allocated as a - direct buffer, in which case the Java virtual machine will make a - best effort to perform native I/O operations directly upon it.
A byte buffer can be created by {@link - java.nio.channels.FileChannel#map mapping} 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.
A byte buffer provides access to its content as either a heterogeneous - or homogeneous sequence of binary data - of any non-boolean primitive type, in either big-endian or little-endian byte order.
Unless otherwise noted, passing a 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 - - - --- /dev/null 2015-05-14 15:34:33.463848421 -0700 +++ new/src/java.base/share/classes/java/nio/package-info.java 2015-05-21 15:52:05.366550724 -0700 @@ -0,0 +1,141 @@ +/* + * Copyright (c) 2000, 2013, 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. + * + * + *
The central abstractions of the NIO APIs are:
+ * + *Buffers, which are containers for data; + *
Charsets and their
+ * associated decoders and encoders,
which
+ * translate between bytes and Unicode characters;
Channels of
+ * various types, which represent connections
to entities
+ * capable of performing I/O operations; and
Selectors and selection keys, which
+ * together with
selectable channels define a multiplexed,
+ * non-blocking
I/O facility.
The 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, 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. + * + * + * + *
+ * + *+ *
+ * Buffers Description + * {@link java.nio.Buffer} + *Position, limit, and capacity; + *
clear, flip, rewind, and mark/reset+ * {@link java.nio.ByteBuffer} + *Get/put, compact, views; allocate, wrap + * {@link java.nio.MappedByteBuffer} + *A byte buffer mapped to a file + * {@link java.nio.CharBuffer} + *Get/put, compact; allocate, wrap + * {@link java.nio.DoubleBuffer} + *' ' + * {@link java.nio.FloatBuffer} + *' ' + * {@link java.nio.IntBuffer} + *' ' + * {@link java.nio.LongBuffer} + *' ' + * {@link java.nio.ShortBuffer} + *' ' + * {@link java.nio.ByteOrder} + *Typesafe enumeration for byte orders
A buffer is a container for a fixed amount of data of a + * specific primitive type. In addition to its content a buffer has a + * position, which is the index of the next element to be read + * or written, and a limit, 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 clearing, flipping, and rewinding, for + * marking the current position, and for resetting the + * position to the previous mark. + * + *
There is a buffer class for each non-boolean primitive type. + * Each class defines a family of get and put methods + * for moving data out of and in to a buffer, methods for + * compacting, duplicating, and slicing a buffer, + * and static methods for allocating a new buffer as well as + * for wrapping an existing array into a buffer. + * + *
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: + * + *
A byte buffer can be allocated as a direct buffer, in which + * case the Java virtual machine will make a best effort to perform + * native I/O operations directly upon it.
A byte buffer can be created by {@link + * java.nio.channels.FileChannel#map mapping} 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.
A byte buffer provides access to its content as either a + * heterogeneous or homogeneous sequence of binary data of any + * non-boolean primitive type, in either big-endian or little-endian + * byte order.
Unless otherwise noted, passing a 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; \ No newline at end of file