java.lang.Object | +--java.io.InputStream | +--java.io.FilterInputStream | +--java.io.BufferedInputStream
Untamed: A BufferedInputStream adds
functionality to another input stream-namely,
the ability to buffer the input and to
support the mark and reset
methods. When the BufferedInputStream
is created, an internal buffer array is
created. As bytes from the stream are read
or skipped, the internal buffer is refilled
as necessary from the contained input stream,
many bytes at a time. The mark
operation remembers a point in the input
stream and the reset operation
causes all the bytes read since the most
recent mark operation to be
reread before new bytes are taken from
the contained input stream.
protected int
marklimit
mark method before subsequent calls to the
reset method fail.
BufferedInputStream(InputStream in)
BufferedInputStream
and saves its argument, the input stream
in, for later use.
BufferedInputStream(InputStream in,
int size)
BufferedInputStream
with the specified buffer size,
and saves its argument, the input stream
in, for later use.
int
available()
void
close()
private void
fill()
int
read(byte[] b,
int off,
int len)
private int
read1(byte[] b,
int off,
int len)
private static int defaultBufferSize
protected byte[] buf
protected int count
0 through buf.length;
elements buf[0] through buf[count-1]
contain buffered input data obtained
from the underlying input stream.
protected int pos
buf array.
This value is always in the range 0
through count. If it is less
than count, then buf[pos]
is the next byte to be supplied as input;
if it is equal to count, then
the next read or skip
operation will require more bytes to be
read from the contained input stream.
java.io.BufferedInputStream#bufprotected int markpos
pos field at the time the last
mark method was called.
This value is always
in the range -1 through pos.
If there is no marked position in the input
stream, this field is -1. If
there is a marked position in the input
stream, then buf[markpos]
is the first byte to be supplied as input
after a reset operation. If
markpos is not -1,
then all bytes from positions buf[markpos]
through buf[pos-1] must remain
in the buffer array (though they may be
moved to another place in the buffer array,
with suitable adjustments to the values
of count, pos,
and markpos); they may not
be discarded unless and until the difference
between pos and markpos
exceeds marklimit.
java.io.BufferedInputStream#mark(int),
java.io.BufferedInputStream#posprotected int marklimit
mark method before subsequent calls to the
reset method fail.
Whenever the difference between pos
and markpos exceeds marklimit,
then the mark may be dropped by setting
markpos to -1.
java.io.BufferedInputStream#mark(int),
java.io.BufferedInputStream#reset()public BufferedInputStream(InputStream in)
BufferedInputStream
and saves its argument, the input stream
in, for later use. An internal
buffer array is created and stored in buf.
in - the underlying input stream.public BufferedInputStream(InputStream in, int size)
BufferedInputStream
with the specified buffer size,
and saves its argument, the input stream
in, for later use. An internal
buffer array of length size
is created and stored in buf.
in - the underlying input stream.size - the buffer size.private void ensureOpen() throws IOException
private void fill() throws IOException
public int read() throws IOException
read
method of InputStream.
read in class FilterInputStream-1 if the end of the
stream is reached.
IOExceptionjava.io.FilterInputStream#inprivate int read1(byte[] b, int off, int len) throws IOException
public int read(byte[] b, int off, int len) throws IOException
This method implements the general contract of the corresponding
readInputStreamread method of the underlying stream. This
iterated read continues until one of the following
conditions becomes true:
read method of the underlying stream returns
-1, indicating end-of-file, or
available method of the underlying stream
returns zero, indicating that further input requests would block.
read on the underlying stream returns
-1 to indicate end-of-file then this method returns
-1. Otherwise this method returns the number of bytes
actually read.
Subclasses of this class are encouraged, but not required, to attempt to read as many bytes as possible in the same fashion.
read in class FilterInputStreamb - destination buffer.off - offset at which to start storing bytes.len - maximum number of bytes to read.
-1 if the end of
the stream has been reached.
IOExceptionjava.io.FilterInputStream#inpublic long skip(long n) throws IOException
skip
method of InputStream.
skip in class FilterInputStreamn - the number of bytes to be skipped.
IOExceptionpublic int available() throws IOException
The available method of
BufferedInputStream returns the sum of the the number
of bytes remaining to be read in the buffer
(count - pos)
and the result of calling the available method of the
underlying input stream.
available in class FilterInputStreamIOExceptionjava.io.FilterInputStream#inpublic void mark(int readlimit)
mark
method of InputStream.
mark in class FilterInputStreamreadlimit - the maximum limit of bytes that can be read before
the mark position becomes invalid.java.io.BufferedInputStream#reset()public void reset() throws IOException
reset
method of InputStream.
If markpos is -1
(no mark has been set or the mark has been
invalidated), an IOException
is thrown. Otherwise, pos is
set equal to markpos.
reset in class FilterInputStreamIOExceptionjava.io.BufferedInputStream#mark(int)public boolean markSupported()
mark
and reset methods. The markSupported
method of BufferedInputStream returns
true.
markSupported in class FilterInputStreamboolean indicating if this stream type supports
the mark and reset methods.java.io.InputStream#mark(int),
java.io.InputStream#reset()public void close() throws IOException
close in class FilterInputStreamIOExceptionjava.io.FilterInputStream#in