Class java.io.BufferedInputStream
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Class java.io.BufferedInputStream

java.lang.Object
   |
   +----java.io.InputStream
           |
           +----java.io.FilterInputStream
                   |
                   +----java.io.BufferedInputStream

public class BufferedInputStream
extends FilterInputStream
A buffered input stream. This stream lets you read in characters from a stream without causing a read every time. The data is read into a buffer, subsequent reads result in a fast buffer access.

Variable Index

 o buf
The buffer where data is stored.
 o count
The number of bytes in the buffer.
 o marklimit
The maximum readahead allowed after a mark() before subsequent calls to reset() fail.
 o markpos
The position in the buffer of the current mark.
 o pos
The current position in the buffer.

Constructor Index

 o BufferedInputStream(InputStream)
Creates a new buffered stream with a default buffer size.
 o BufferedInputStream(InputStream, int)
Creates a new buffered stream with the specified buffer size.

Method Index

 o available()
Returns the number of bytes that can be read without blocking.
 o mark(int)
Marks the current position in the input stream.
 o markSupported()
Returns a boolean indicating if this stream type supports mark/reset.
 o read()
Reads a byte of data.
 o read(byte[], int, int)
Reads into an array of bytes.
 o reset()
Repositions the stream to the last marked position.
 o skip(long)
Skips n bytes of input.

Variables

 o buf
  protected byte buf[]
The buffer where data is stored.
 o count
  protected int count
The number of bytes in the buffer.
 o pos
  protected int pos
The current position in the buffer.
 o markpos
  protected int markpos
The position in the buffer of the current mark. This mark is set to -1 if there is no current mark.
 o marklimit
  protected int marklimit
The maximum readahead allowed after a mark() before subsequent calls to reset() fail.

Constructors

 o BufferedInputStream
  public BufferedInputStream(InputStream in)
Creates a new buffered stream with a default buffer size.
Parameters:
in - the input stream
 o BufferedInputStream
  public BufferedInputStream(InputStream in,
                             int size)
Creates a new buffered stream with the specified buffer size.
Parameters:
in - the input stream
size - the buffer size

Methods

 o read
  public synchronized int read() throws IOException
Reads a byte of data. This method will block if no input is available.
Returns:
the byte read, or -1 if the end of the stream is reached.
Throws: IOException
If an I/O error has occurred.
Overrides:
read in class FilterInputStream
 o read
  public synchronized int read(byte b[],
                               int off,
                               int len) throws IOException
Reads into an array of bytes. Blocks until some input is available.
Parameters:
b - the buffer into which the data is read
off - the start offset of the data
len - the maximum number of bytes read
Returns:
the actual number of bytes read, -1 is returned when the end of the stream is reached.
Throws: IOException
If an I/O error has occurred.
Overrides:
read in class FilterInputStream
 o skip
  public synchronized long skip(long n) throws IOException
Skips n bytes of input.
Parameters:
n - the number of bytes to be skipped
Returns:
the actual number of bytes skipped.
Throws: IOException
If an I/O error has occurred.
Overrides:
skip in class FilterInputStream
 o available
  public synchronized int available() throws IOException
Returns the number of bytes that can be read without blocking. This total is the number of bytes in the buffer and the number of bytes available from the input stream.
Returns:
the number of available bytes.
Overrides:
available in class FilterInputStream
 o mark
  public synchronized void mark(int readlimit)
Marks the current position in the input stream. A subsequent call to the reset() method will reposition the stream at the last marked position so that subsequent reads will re-read the same bytes. The stream promises to allow readlimit bytes to be read before the mark position gets invalidated.
Parameters:
readlimit - the maximum limit of bytes allowed to be read before the mark position becomes invalid.
Overrides:
mark in class FilterInputStream
 o reset
  public synchronized void reset() throws IOException
Repositions the stream to the last marked position. If the stream has not been marked, or if the mark has been invalidated, an IOException is thrown. Stream marks are intended to be used in situations where you need to read ahead a little to see what's in the stream. Often this is most easily done by invoking some general parser. If the stream is of the type handled by the parser, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails. If an exception gets tossed within readlimit bytes, the parser will allow the outer code to reset the stream and to try another parser.
Throws: IOException
If the stream has not been marked or if the mark has been invalidated.
Overrides:
reset in class FilterInputStream
 o markSupported
  public boolean markSupported()
Returns a boolean indicating if this stream type supports mark/reset.
Overrides:
markSupported in class FilterInputStream

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