public class BufferedInputStream
extends java.io.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 and 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.
|
| Constructor and Description |
|---|
BufferedInputStream(java.io.InputStream in)
Creates a
BufferedInputStream and saves its argument, the input stream in, for later
use. |
BufferedInputStream(java.io.InputStream in,
int size)
Creates a
BufferedInputStream with the specified buffer size, and saves its argument, the input
stream in, for later use. |
| Modifier and Type | Method and 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(int readlimit)
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(byte[] b,
int off,
int len)
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(long n)
See the general contract of the
skip method of InputStream. |
@Nullable 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.
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.
public BufferedInputStream(java.io.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(java.io.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.java.lang.IllegalArgumentException - if size <= 0.public int read()
throws java.io.IOException
read method of InputStream.read in class java.io.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.FilterInputStream.inpublic int read(byte[] b,
int off,
int len)
throws java.io.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 java.io.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.IOException - if this input stream has been closed by invoking its close() method, or an I/O error
occurs.public long skip(long n)
throws java.io.IOException
skip method of InputStream.skip in class java.io.FilterInputStreamIOException - if the stream does not support seek, or if this input stream has been closed by invoking its
close() method, or an I/O error occurs.public int available()
throws java.io.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 java.io.FilterInputStreamIOException - 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 java.io.FilterInputStreamreadlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.reset()public void reset()
throws java.io.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.
public boolean markSupported()
mark and reset methods. The
markSupported method of BufferedInputStream returns true.markSupported in class java.io.FilterInputStreamboolean indicating if this stream type supports the mark and
reset methods.InputStream.mark(int),
InputStream.reset()public void close()
throws java.io.IOException
close in interface java.io.Closeableclose in interface java.lang.AutoCloseableclose in class java.io.FilterInputStreamIOException - if an I/O error occurs.