Closeable
, AutoCloseable
public class BufferedInputStream extends FilterInputStream
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.Modifier and Type | Field | Description |
---|---|---|
protected byte[] |
buf |
The internal buffer array where the data is stored. |
protected int |
count |
The index one greater than the index of the last valid byte in the buffer. |
protected int |
marklimit |
The maximum read ahead allowed after a call to the mark method before subsequent calls to the reset method fail. |
protected int |
markpos |
The value of the pos field at the time the last mark method was called. |
protected int |
pos |
The current position in the buffer. |
in
Constructor | Description |
---|---|
BufferedInputStream |
Creates a BufferedInputStream and saves its argument, the input stream in , for later use. |
BufferedInputStream |
Creates a BufferedInputStream with the specified buffer size, and saves its argument, the input stream in , for later use. |
Modifier and Type | Method | Description |
---|---|---|
int |
available() |
Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. |
void |
close() |
Closes this input stream and releases any system resources associated with the stream. |
void |
mark |
See the general contract of the mark method of InputStream . |
boolean |
markSupported() |
Tests if this input stream supports the mark and reset methods. |
int |
read() |
See the general contract of the read method of InputStream . |
int |
read |
Reads bytes from this byte-input stream into the specified byte array, starting at the given offset. |
void |
reset() |
See the general contract of the reset method of InputStream . |
long |
skip |
See the general contract of the skip method of InputStream . |
read
nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo
protected volatile 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.
protected 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
.
protected 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
.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.IllegalArgumentException
- if size <= 0
.public int read() throws IOException
read
method of InputStream
.read
in class FilterInputStream
-1
if the end of the stream is reached.IOException
- if this input stream has been closed by invoking its close()
method, or an I/O error occurs.public int read(byte[] b, int off, int len) throws IOException
This method implements the general contract of the corresponding read
method of the InputStream
class. As an additional convenience, it attempts to read as many bytes as possible by repeatedly invoking the read
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 FilterInputStream
b
- 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.IOException
- if this input stream has been closed by invoking its close()
method, or an I/O error occurs.IndexOutOfBoundsException
- If off
is negative, len
is negative, or len
is greater than b.length - off
public long skip(long n) throws IOException
skip
method of InputStream
.skip
in class FilterInputStream
n
- the number of bytes to be skipped.IOException
- if this input stream has been closed by invoking its close()
method, in.skip(n)
throws an IOException, or an I/O error occurs.public int available() throws IOException
This method returns the sum of the number of bytes remaining to be read in the buffer (count - pos
) and the result of calling the in
.available()
.
available
in class FilterInputStream
IOException
- if this input stream has been closed by invoking its close()
method, or an I/O error occurs.public void mark(int readlimit)
mark
method of InputStream
.mark
in class FilterInputStream
readlimit
- the maximum limit of bytes that can be read before the mark position becomes invalid.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 FilterInputStream
IOException
- if this stream has not been marked or, if the mark has been invalidated, or the stream has been closed by invoking its close()
method, or an I/O error occurs.public boolean markSupported()
mark
and reset
methods. The markSupported
method of BufferedInputStream
returns true
.markSupported
in class FilterInputStream
boolean
indicating if this stream type supports the mark
and reset
methods.public void close() throws IOException
close
in interface AutoCloseable
close
in interface Closeable
close
in class FilterInputStream
IOException
- if an I/O error occurs.
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/io/BufferedInputStream.html