A container for data of a specific primitive type.
A byte buffer.
A typesafe enumeration for byte orders.
A char buffer.
A double buffer.
A float buffer.
An int buffer.
A long buffer.
A direct byte buffer whose content is a memory-mapped region of a file.
A short buffer.
Unchecked exception thrown when a relative put operation reaches the target buffer's limit.
Unchecked exception thrown when a relative get operation reaches the source buffer's limit.
Unchecked exception thrown when an attempt is made to reset a buffer when its mark is not defined.
Unchecked exception thrown when a content-mutation method such as put or compact is invoked upon a read-only buffer.
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;
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
The java.nio package defines the buffer classes, which are used
throughout the NIO APIs. The charset API is defined in the
java.nio.charset package, and the channel and selector APIs are defined in the
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
Position, limit, and capacity;
clear, flip, rewind, and mark/reset
Get/put, compact, views; allocate, wrap
A byte buffer mapped to a file
Get/put, compact; allocate, wrap
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
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
mapping a region of a
file directly into memory, in which case a few additional file-related
operations defined in the
MappedByteBuffer class are
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
NullPointerException to be thrown.
Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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