java.io.ByteArrayInputStream
ByteArrayInputStream
contains an internal buffer that contains bytes that
may be read from the stream. An internal counter keeps track of the next byte to
be supplied by the read
method. See also StringBufferInputStream
(§22.7).
public classByteArrayInputStream
extends InputStream { protected byte[]buf
; protected intpos
; protected intcount
; publicByteArrayInputStream
(byte[] buf); publicByteArrayInputStream
(byte[] buf, int offset, int length); public intread
() throws NullPointerException, IndexOutOfBoundsException; public intread
(byte[] b, int off, int len) throws NullPointerException, IndexOutOfBoundsException; public longskip
(long n); public intavailable
(); public voidreset
(); }
22.6.1 protected byte[]
buf
;
An array of bytes that was provided by the creator of the stream. Elements buf[0]
through buf[count-1]
are the only bytes that can ever be read from the stream;
element buf[pos]
is the next byte to be read.
22.6.2 protected int
pos
;
This value should always be nonnegative and not larger than the value of count
.
The next byte to be read from this stream will be buf[pos]
.
22.6.3 protected int
count
;
This value should always be nonnegative and not larger than the length of buf
. It
is one greater than the position of the last byte within buf
that can ever be read
from this stream.
22.6.4 public
ByteArrayInputStream
(byte[] buf)
This constructor initializes a newly created ByteArrayInputStream
so that it
uses buf
as its buffer array. The initial value of pos
is 0
and the initial value of
count
is the length of buf
.
22.6.5 public
ByteArrayInputStream
(byte[] buf,
int offset, int length)
This constructor initializes a newly created ByteArrayInputStream
so that it
uses buf
as its buffer array. The initial value of pos
is offset
and the initial value
of count
is offset+len
.
Note that if bytes are simply read from the resulting input stream, elements buf[pos]
through buf[pos+len-1]
will be read; however, if a reset
operation (§22.6.10) is performed, then bytes buf[0]
through buf[pos-1]
will then become available for input.
22.6.6 public int
read
()
throws NullPointerException, IndexOutOfBoundsException
If pos
equals count
, then -1
is returned to indicate end of file. Otherwise, the
value buf[pos]&0xff
is returned; just before the return, pos
is incremented by 1
.
Implements the read
method of InputStream
(§22.3.1).
22.6.7 public int
read
(byte[] b, int off, int len)
throws NullPointerException, IndexOutOfBoundsException
If pos
equals count
, then -1
is returned to indicate end of file. Otherwise, the
number k
of bytes read is equal to the smaller of len
and count-pos
. If k
is positive,
then bytes buf[pos]
through buf[pos+k-1]
are copied into b[off]
through b[off+k-1]
in the manner performed by System.arraycopy
(§20.18.16). The value k
is added into pos
and k
is returned.
Overrides the read
method of InputStream
(§22.3.3).
22.6.8 public long
skip
(long n)
The actual number k
of bytes to be skipped is equal to the smaller of n
and
count-pos
. The value k
is added into pos
and k
is returned.
Overrides the skip
method of InputStream
(§22.3.4).
22.6.9 public int
available
()
The quantity count-pos
is returned.
Overrides the available
method of InputStream
(§22.3.5).
22.6.10 public void
reset
()
Overrides the reset
method of InputStream
(§22.3.8).
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Java Language Specification (HTML generated by Suzette Pelouch on February 24, 1998)
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