Package java.nio

Defines buffers, which are containers for data.

See: Description

Class Summary

Class	Description
Buffer	A container for data of a specific primitive type.
ByteBuffer	A byte buffer.
ByteOrder	A typesafe enumeration for byte orders.
FloatBuffer	A float buffer.
IntBuffer	An int buffer.
ShortBuffer	A short buffer.

Exception Summary

Exception	Description
BufferOverflowException	Unchecked exception thrown when a relative put operation reaches the target buffer's limit.
BufferUnderflowException	Unchecked exception thrown when a relative get operation reaches the source buffer's limit.

Package java.nio Description

Defines buffers, which are containers for data.

The NIO Buffer API subset consists of portions of the Buffer, ByteBuffer, ShortBuffer, IntBuffer, and FloatBuffer classes as well as the support classes BufferOverflowException, and BufferUnderflowException.

Only basic buffer functionality is supported, and does not include mapped buffers, charsets, or selectors, read-only buffers, mark, reset, and rewind. Primitive data types are supported only for byte, short, int, and float. No support is provided for data types char, long, or double.

The central abstractions of the NIO APIs are:

• Buffers, which are containers for data.

• Channels of various types, which represent connections
  to entities capable of performing I/O operations

The java.nio package defines the buffer classes, which are used throughout the NIO APIs.

Buffers	Description
Buffer	Position, limit, and capacity; clear, and flip
ByteBuffer	Get/put, views; allocate, wrap
FloatBuffer	Get/put, views; wrap
IntBuffer	Get/put, views; wrap
ShortBuffer	Get/put, views; wrap

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 Buffer class defines these properties as well as methods for clearing, flipping, and rewinding.

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 slicing a buffer, and static methods for wrapping an existing array into a buffer.

Byte buffers 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 provides access to its content as either a heterogeneous or homogeneous sequence of binary data of any non-boolean primitive type, in platform 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 NullPointerException to be thrown.

Note: Unlike their Java SE8 counterparts, the CLDC8 versions of ByteBuffer, ShortBuffer, IntBuffer and FloatBuffer are not abstract but are concrete classes.

Since:

CLDC1.8