java.io
Class BufferedInputStream

java.lang.Object sample code for java.lang.Object definition code for java.lang.Object 
  extended by java.io.InputStream sample code for java.io.InputStream definition code for java.io.InputStream 
      extended by java.io.FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream 
          extended by java.io.BufferedInputStream
All Implemented Interfaces:
Closeable sample code for java.io.Closeable definition code for java.io.Closeable

public class BufferedInputStream
extends FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream

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.

Since:
JDK1.0

Field Summary
protected  byte[] buf sample code for java.io.BufferedInputStream.buf definition code for java.io.BufferedInputStream.buf
          The internal buffer array where the data is stored.
protected  int count sample code for java.io.BufferedInputStream.count definition code for java.io.BufferedInputStream.count
          The index one greater than the index of the last valid byte in the buffer.
protected  int marklimit sample code for java.io.BufferedInputStream.marklimit definition code for java.io.BufferedInputStream.marklimit
          The maximum read ahead allowed after a call to the mark method before subsequent calls to the reset method fail.
protected  int markpos sample code for java.io.BufferedInputStream.markpos definition code for java.io.BufferedInputStream.markpos
          The value of the pos field at the time the last mark method was called.
protected  int pos sample code for java.io.BufferedInputStream.pos definition code for java.io.BufferedInputStream.pos
          The current position in the buffer.
 
Fields inherited from class java.io.FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
in sample code for java.io.FilterInputStream.in definition code for java.io.FilterInputStream.in
 
Constructor Summary
BufferedInputStream sample code for java.io.BufferedInputStream.BufferedInputStream(java.io.InputStream) definition code for java.io.BufferedInputStream.BufferedInputStream(java.io.InputStream) (InputStream sample code for java.io.InputStream definition code for java.io.InputStream  in)
          Creates a BufferedInputStream and saves its argument, the input stream in, for later use.
BufferedInputStream sample code for java.io.BufferedInputStream.BufferedInputStream(java.io.InputStream, int) definition code for java.io.BufferedInputStream.BufferedInputStream(java.io.InputStream, int) (InputStream sample code for java.io.InputStream definition code for 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.
 
Method Summary
 int available sample code for java.io.BufferedInputStream.available() definition code for java.io.BufferedInputStream.available() ()
          Returns the number of bytes that can be read from this input stream without blocking.
 void close sample code for java.io.BufferedInputStream.close() definition code for java.io.BufferedInputStream.close() ()
          Closes this input stream and releases any system resources associated with the stream.
 void mark sample code for java.io.BufferedInputStream.mark(int) definition code for java.io.BufferedInputStream.mark(int) (int readlimit)
          See the general contract of the mark method of InputStream.
 boolean markSupported sample code for java.io.BufferedInputStream.markSupported() definition code for java.io.BufferedInputStream.markSupported() ()
          Tests if this input stream supports the mark and reset methods.
 int read sample code for java.io.BufferedInputStream.read() definition code for java.io.BufferedInputStream.read() ()
          See the general contract of the read method of InputStream.
 int read sample code for java.io.BufferedInputStream.read(byte[], int, int) definition code for java.io.BufferedInputStream.read(byte[], int, int) (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 sample code for java.io.BufferedInputStream.reset() definition code for java.io.BufferedInputStream.reset() ()
          See the general contract of the reset method of InputStream.
 long skip sample code for java.io.BufferedInputStream.skip(long) definition code for java.io.BufferedInputStream.skip(long) (long n)
          See the general contract of the skip method of InputStream.
 
Methods inherited from class java.io.FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
read sample code for java.io.FilterInputStream.read(byte[]) definition code for java.io.FilterInputStream.read(byte[])
 
Methods inherited from class java.lang.Object sample code for java.lang.Object definition code for java.lang.Object
clone sample code for java.lang.Object.clone() definition code for java.lang.Object.clone() , equals sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) , finalize sample code for java.lang.Object.finalize() definition code for java.lang.Object.finalize() , getClass sample code for java.lang.Object.getClass() definition code for java.lang.Object.getClass() , hashCode sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , notify sample code for java.lang.Object.notify() definition code for java.lang.Object.notify() , notifyAll sample code for java.lang.Object.notifyAll() definition code for java.lang.Object.notifyAll() , toString sample code for java.lang.Object.toString() definition code for java.lang.Object.toString() , wait sample code for java.lang.Object.wait() definition code for java.lang.Object.wait() , wait sample code for java.lang.Object.wait(long) definition code for java.lang.Object.wait(long) , wait sample code for java.lang.Object.wait(long, int) definition code for java.lang.Object.wait(long, int)
 

Field Detail

buf sample code for java.io.BufferedInputStream.buf

protected volatile byte[] buf
The internal buffer array where the data is stored. When necessary, it may be replaced by another array of a different size.


count sample code for java.io.BufferedInputStream.count

protected int count
The index one greater than the index of the last valid byte in the buffer. This value is always in the range 0 through buf.length; elements buf[0] through buf[count-1] contain buffered input data obtained from the underlying input stream.


pos sample code for java.io.BufferedInputStream.pos

protected int pos
The current position in the buffer. This is the index of the next character to be read from the 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.

See Also:
buf sample code for java.io.BufferedInputStream.buf definition code for java.io.BufferedInputStream.buf

markpos sample code for java.io.BufferedInputStream.markpos

protected int markpos
The value of the 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.

See Also:
mark(int) sample code for java.io.BufferedInputStream.mark(int) definition code for java.io.BufferedInputStream.mark(int) , pos sample code for java.io.BufferedInputStream.pos definition code for java.io.BufferedInputStream.pos

marklimit sample code for java.io.BufferedInputStream.marklimit

protected int marklimit
The maximum read ahead allowed after a call to the 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.

See Also:
mark(int) sample code for java.io.BufferedInputStream.mark(int) definition code for java.io.BufferedInputStream.mark(int) , reset() sample code for java.io.BufferedInputStream.reset() definition code for java.io.BufferedInputStream.reset()
Constructor Detail

BufferedInputStream sample code for java.io.BufferedInputStream(java.io.InputStream) definition code for java.io.BufferedInputStream(java.io.InputStream)

public BufferedInputStream(InputStream sample code for java.io.InputStream definition code for java.io.InputStream  in)
Creates a BufferedInputStream and saves its argument, the input stream in, for later use. An internal buffer array is created and stored in buf.

Parameters:
in - the underlying input stream.

BufferedInputStream sample code for java.io.BufferedInputStream(java.io.InputStream, int) definition code for java.io.BufferedInputStream(java.io.InputStream, int)

public BufferedInputStream(InputStream sample code for java.io.InputStream definition code for 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. An internal buffer array of length size is created and stored in buf.

Parameters:
in - the underlying input stream.
size - the buffer size.
Throws:
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if size <= 0.
Method Detail

read sample code for java.io.BufferedInputStream.read() definition code for java.io.BufferedInputStream.read()

public int read()
         throws IOException sample code for java.io.IOException definition code for java.io.IOException 
See the general contract of the read method of InputStream.

Overrides:
read sample code for java.io.FilterInputStream.read() definition code for java.io.FilterInputStream.read() in class FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
Returns:
the next byte of data, or -1 if the end of the stream is reached.
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in sample code for java.io.FilterInputStream.in definition code for java.io.FilterInputStream.in

read sample code for java.io.BufferedInputStream.read(byte[], int, int) definition code for java.io.BufferedInputStream.read(byte[], int, int)

public int read(byte[] b,
                int off,
                int len)
         throws IOException sample code for java.io.IOException definition code for java.io.IOException 
Reads bytes from this byte-input stream into the specified byte array, starting at the given offset.

This method implements the general contract of the corresponding read sample code for java.io.InputStream.read(byte[], int, int) definition code for java.io.InputStream.read(byte[], int, int) method of the InputStream sample code for java.io.InputStream definition code for java.io.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:

If the first 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.

Overrides:
read sample code for java.io.FilterInputStream.read(byte[], int, int) definition code for java.io.FilterInputStream.read(byte[], int, int) in class FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
Parameters:
b - destination buffer.
off - offset at which to start storing bytes.
len - maximum number of bytes to read.
Returns:
the number of bytes read, or -1 if the end of the stream has been reached.
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in sample code for java.io.FilterInputStream.in definition code for java.io.FilterInputStream.in

skip sample code for java.io.BufferedInputStream.skip(long) definition code for java.io.BufferedInputStream.skip(long)

public long skip(long n)
          throws IOException sample code for java.io.IOException definition code for java.io.IOException 
See the general contract of the skip method of InputStream.

Overrides:
skip sample code for java.io.FilterInputStream.skip(long) definition code for java.io.FilterInputStream.skip(long) in class FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
Parameters:
n - the number of bytes to be skipped.
Returns:
the actual number of bytes skipped.
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - if an I/O error occurs.

available sample code for java.io.BufferedInputStream.available() definition code for java.io.BufferedInputStream.available()

public int available()
              throws IOException sample code for java.io.IOException definition code for java.io.IOException 
Returns the number of bytes that can be read from this input stream without blocking.

The available method of BufferedInputStream returns the sum of 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.

Overrides:
available sample code for java.io.FilterInputStream.available() definition code for java.io.FilterInputStream.available() in class FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
Returns:
the number of bytes that can be read from this input stream without blocking.
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in sample code for java.io.FilterInputStream.in definition code for java.io.FilterInputStream.in

mark sample code for java.io.BufferedInputStream.mark(int) definition code for java.io.BufferedInputStream.mark(int)

public void mark(int readlimit)
See the general contract of the mark method of InputStream.

Overrides:
mark sample code for java.io.FilterInputStream.mark(int) definition code for java.io.FilterInputStream.mark(int) in class FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
Parameters:
readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.
See Also:
reset() sample code for java.io.BufferedInputStream.reset() definition code for java.io.BufferedInputStream.reset()

reset sample code for java.io.BufferedInputStream.reset() definition code for java.io.BufferedInputStream.reset()

public void reset()
           throws IOException sample code for java.io.IOException definition code for java.io.IOException 
See the general contract of the 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.

Overrides:
reset sample code for java.io.FilterInputStream.reset() definition code for java.io.FilterInputStream.reset() in class FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - if this stream has not been marked or if the mark has been invalidated.
See Also:
mark(int) sample code for java.io.BufferedInputStream.mark(int) definition code for java.io.BufferedInputStream.mark(int)

markSupported sample code for java.io.BufferedInputStream.markSupported() definition code for java.io.BufferedInputStream.markSupported()

public boolean markSupported()
Tests if this input stream supports the mark and reset methods. The markSupported method of BufferedInputStream returns true.

Overrides:
markSupported sample code for java.io.FilterInputStream.markSupported() definition code for java.io.FilterInputStream.markSupported() in class FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
Returns:
a boolean indicating if this stream type supports the mark and reset methods.
See Also:
InputStream.mark(int) sample code for java.io.InputStream.mark(int) definition code for java.io.InputStream.mark(int) , InputStream.reset() sample code for java.io.InputStream.reset() definition code for java.io.InputStream.reset()

close sample code for java.io.BufferedInputStream.close() definition code for java.io.BufferedInputStream.close()

public void close()
           throws IOException sample code for java.io.IOException definition code for java.io.IOException 
Closes this input stream and releases any system resources associated with the stream.

Specified by:
close sample code for java.io.Closeable.close() definition code for java.io.Closeable.close() in interface Closeable sample code for java.io.Closeable definition code for java.io.Closeable
Overrides:
close sample code for java.io.FilterInputStream.close() definition code for java.io.FilterInputStream.close() in class FilterInputStream sample code for java.io.FilterInputStream definition code for java.io.FilterInputStream
Throws:
IOException sample code for java.io.IOException definition code for java.io.IOException - if an I/O error occurs.
See Also:
FilterInputStream.in sample code for java.io.FilterInputStream.in definition code for java.io.FilterInputStream.in