java.io
Class PushbackInputStream

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

public class PushbackInputStream

extends FilterInputStream

An input stream that has a 1 byte push back buffer.

Field Summary

protected int

pushBack Push back character.

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

PushbackInputStream(InputStream in)
Creates a PushbackInputStream.

Method Summary

int	available() Returns the number of bytes that can be read.
boolean	markSupported() Returns true if this stream type supports mark/reset.
int	read() Reads a byte of data.
int	read(byte[] bytes, int offset, int length) Reads into an array of bytes.
void	unread(int ch) Pushes back a character.

Methods inherited from class java.io.FilterInputStream

close, mark, read, reset, skip

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

pushBack

protected int pushBack

Push back character.

Constructor Detail

PushbackInputStream

public PushbackInputStream(InputStream in)

Creates a PushbackInputStream.

Parameters:

in - the input stream

Method Detail

read

public int read()
         throws IOException

Reads a byte of data. This method will block if no input is available.

Overrides:

read in class FilterInputStream

Returns:

the byte read, or -1 if the end of the stream is reached.

Throws:

IOException - If an I/O error has occurred.

read

public int read(byte[] bytes,
                int offset,
                int length)
         throws IOException

Reads into an array of bytes. This method blocks until some input is available.

Overrides:

read in class FilterInputStream

Parameters:

bytes - the buffer into which the data is read

offset - the start offset of the data

length - 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.

unread

public void unread(int ch)
            throws IOException

Pushes back a character.

Parameters:

ch - the character to push back.

Throws:

IOException - If an attempt to push back more than one character is made.

available

public int available()
              throws IOException

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

Overrides:

available in class FilterInputStream

Returns:

the number of available bytes

IOException

markSupported

public boolean markSupported()

Returns true if this stream type supports mark/reset.

Overrides:

markSupported in class FilterInputStream

Returns:

true if this stream type supports mark/reset; false otherwise.