See: Description
Class | Description |
---|---|
Buffer | A container for data of a specific primitive type. |
ByteBuffer | A byte buffer. |
ByteOrder | A typesafe enumeration for byte orders. |
CharBuffer | A char buffer. |
DoubleBuffer | A double buffer. |
FloatBuffer | A float buffer. |
IntBuffer | An int buffer. |
LongBuffer | A long buffer. |
MappedByteBuffer | A direct byte buffer whose content is a memory-mapped region of a file. |
ShortBuffer | A short buffer. |
Exception | Description |
---|---|
BufferOverflowException | Unchecked exception thrown when a relativeput operation reaches the target buffer's limit. |
BufferUnderflowException | Unchecked exception thrown when a relativeget operation reaches the source buffer's limit. |
InvalidMarkException | Unchecked exception thrown when an attempt is made to reset a buffer when its mark is not defined. |
ReadOnlyBufferException | Unchecked exception thrown when a content-mutation method such asput orcompact is invoked upon a read-only buffer. |
The central abstractions of the NIO APIs are:
Buffers, which are containers for data;
Charsets and their associateddecoders andencoders,
which translate between bytes and Unicode characters;
Channels of various types, which represent connections
to entities capable of performing I/O operations; and
Selectors andselection keys, which together with
selectable channels define amultiplexed, non-blocking
I/O facility.
Thejava.nio package defines the buffer classes, which are usedthroughout the NIO APIs. The charset API is defined in thejava.nio.charset
package, and the channel and selector APIs are defined in thejava.nio.channels
package. Each of these subpackages has its ownservice-provider (SPI) subpackage, the contents of which can be used to extendthe platform's default implementations or to construct alternativeimplementations.
Buffers
Description
Buffer
Position, limit, and capacity;
clear, flip, rewind, and mark/resetByteBuffer
Get/put, compact, views; allocate, wrap MappedByteBuffer
A byte buffer mapped to a file CharBuffer
Get/put, compact; allocate, wrap DoubleBuffer
' ' FloatBuffer
' ' IntBuffer
' ' LongBuffer
' ' ShortBuffer
' ' ByteOrder
Typesafe enumeration for byte orders
Abuffer is a container for a fixed amount of data of a specificprimitive type. In addition to its content a buffer has aposition,which is the index of the next element to be read or written, and alimit, which is the index of the first element that should not be reador written. The baseBuffer
class defines these properties aswell as methods forclearing,flipping, andrewinding, formarking the current position, and forresetting the position tothe previous mark.
There is a buffer class for each non-boolean primitive type. Each classdefines a family ofget andput methods for moving data out ofand in to a buffer, methods forcompacting,duplicating, andslicing a buffer, and static methods forallocating a new bufferas well as forwrapping an existing array into a buffer.
Byte buffers are distinguished in that they can be used as the sources andtargets of I/O operations. They also support several features not found in theother buffer classes:
A byte buffer can be allocated as adirect 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 bymapping
a region of a file directly into memory, in which case a few additional file-related operations defined in theMappedByteBuffer
class are available.
A byte buffer provides access to its content as either a heterogeneous or homogeneous sequence ofbinary data of any non-boolean primitive type, in either big-endian or little-endianbyte order.
Unless otherwise noted, passing anull argument to a constructoror method in any class or interface in this package will cause aNullPointerException
to be thrown.