|Known Direct Subclasses|
Known Indirect Subclasses
A container for data of a specific primitive type.
A buffer is a linear, finite sequence of elements of a specific primitive type. Aside from its content, the essential properties of a buffer are its capacity, limit, and position:
A buffer's capacity is the number of elements it contains. The capacity of a buffer is never negative and never changes.
A buffer's limit is the index of the first element that should not be read or written. A buffer's limit is never negative and is never greater than its capacity.
A buffer's position is the index of the next element to be read or written. A buffer's position is never negative and is never greater than its limit.
There is one subclass of this class for each non-boolean primitive type.
Each subclass of this class defines two categories of get and put operations:
Relative operations read or write one or more elements starting at the current position and then increment the position by the number of elements transferred. If the requested transfer exceeds the limit then a relative get operation throws a
BufferUnderflowExceptionand a relative put operation throws a
BufferOverflowException; in either case, no data is transferred.
Absolute operations take an explicit element index and do not affect the position. Absolute get and put operations throw an
IndexOutOfBoundsExceptionif the index argument exceeds the limit.
Data may also, of course, be transferred in to or out of a buffer by the I/O operations of an appropriate channel, which are always relative to the current position.
Marking and resetting
A buffer's mark is the index to which its position will be reset
reset method is invoked. The mark is not always
defined, but when it is defined it is never negative and is never greater
than the position. If the mark is defined then it is discarded when the
position or the limit is adjusted to a value smaller than the mark. If the
mark is not defined then invoking the
reset method causes an
InvalidMarkException to be thrown.
The following invariant holds for the mark, position, limit, and capacity values:
0 <= mark <= position <= limit <= capacity