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# Class java.io.InputStream

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

public class InputStream
extends Object

Abstract class representing an input stream of bytes. All InputStreams are based on this class.

See Also:
  OutputStream, FilterInputStream, BufferedInputStream, DataInputStream, InputStreamBuffer, PushbackInputStream
Version:
  1.9, 31 Jan 1995
Author:
  Arthur van Hoff

##

InputStream()

##

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

##

InputStream

      public InputStream()

##

read

      public abstract int read()

  Reads a byte. Will block if no input is available.
  Returns:
    the byte read, or -1 if the end of the stream is reached.
  Throws: IOException
    i/o error occurred

read

      public int read(byte b[])

  Reads into an array of bytes. Blocks until some input is available.
  Parameters:
    b - the buffer into which the data is read
  Returns:
    the actual number of bytes read, -1 is returned when the end of the stream is reached.
  Throws: IOException
    i/o error occurred

read

      public int read(byte b[],
                      int off,
                      int len)

  Reads into an array of bytes. Blocks until some input is available. For efficiency, this method should be overridden in a subclass (the default implementation reads 1 byte at a time).
  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
    i/o error occurred

skip

      public int skip(int n)

  Skips bytes of input.
  Parameters:
    n - bytes to be skipped
  Returns:
    actual number of bytes skipped
  Throws: IOException
    i/o error occurred

available

      public int available()

  Returns the number of bytes that can be read without blocking.
  Returns:
    the number of available bytes

close

      public void close()

  Closes the input stream. Must be called to release any resources associated with the stream.
  Throws: IOException
    i/o error occurred

mark

      public synchronized void mark(int readlimit)

  Marks the current position in the input stream. A subsequent call to reset() 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.

reset

      public synchronized void reset()

  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 parse, it just chugs along happily. If the stream is *not* of that type, the parser should toss an exception when it fails, which, if it happens within readlimit bytes, allows the outer code to reset the stream and try another parser.

markSupported

      public boolean markSupported()

  Returns true if this stream type supports mark/reset

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