java.lang.Object java.io.InputStream java.io.FilterInputStream java.io.BufferedInputStream
public class BufferedInputStream
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.
Field Summary | |
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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. |
Fields inherited from class java.io. FilterInputStream |
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in |
Constructor Summary | |
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BufferedInputStream
(
InputStream
in) Creates a BufferedInputStream and saves its argument, the input stream in, for later use. |
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BufferedInputStream
(
InputStream
in, int size) Creates a BufferedInputStream with the specified buffer size, and saves its argument, the input stream in, for later use. |
Method Summary | |
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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. |
Methods inherited from class java.io. FilterInputStream |
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read |
Methods inherited from class java.lang. Object |
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clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
Field Detail |
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protected volatile byte[] buf
protected int count
protected int pos
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
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
Constructor Detail |
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public BufferedInputStream(InputStream in)
public BufferedInputStream(InputStream in, int size)
Method Detail |
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public int read() throws IOException
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:
Subclasses of this class are encouraged, but not required, to attempt to read as many bytes as possible in the same fashion.
public long skip(long n) throws IOException
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().
public void mark(int readlimit)
public void reset() throws IOException
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()
public void close() throws IOException