org.yajul.io
Class AbstractByteFilterInputStream

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          org.yajul.io.AbstractByteFilterInputStream

All Implemented Interfaces:

java.io.Closeable

Direct Known Subclasses:

Base64InputStream, TokenizingInputStream

public abstract class AbstractByteFilterInputStream
extends java.io.FilterInputStream

Implements the array based read method to simplify writing 'byte at a time' FilterInputStream classes. Sub-classes need only implement the read() method.
User: josh Date: Nov 27, 2002 Time: 8:38:44 AM

Author:

josh

Field Summary

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

AbstractByteFilterInputStream(java.io.InputStream in)
Creates a new AbstractByteFilterInputStream.

AbstractByteFilterInputStream(java.io.InputStream in, int pushbackBufferSize)
Creates a new AbstractByteFilterInputStream with a built in 'pushback buffer' which enables the 'unread' methods.

Method Summary

protected int	insert(byte[] bytes) Pushes all of the bytes after the first one into the pushback buffer and returns the first byte, effectively inserting the bytes into the stream.
abstract int	read() Reads the next byte of data from this input stream.
int	read(byte[] b, int off, int len) Reads up to len bytes of data from this input stream into an array of bytes.
protected int	readByte() Reads the next byte of data from this input stream.

Methods inherited from class java.io.FilterInputStream

available, close, mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractByteFilterInputStream

public AbstractByteFilterInputStream(java.io.InputStream in,
                                     int pushbackBufferSize)

Creates a new AbstractByteFilterInputStream with a built in 'pushback buffer' which enables the 'unread' methods.

Parameters:

in - The underlying input stream being filtered.

pushbackBufferSize - The size of the pushback buffer.

AbstractByteFilterInputStream

public AbstractByteFilterInputStream(java.io.InputStream in)

Creates a new AbstractByteFilterInputStream.

Parameters:

in - The underlying input stream being filtered.

Method Detail

readByte

protected final int readByte()
                      throws java.io.IOException

Reads the next byte of data from this input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Returns:

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

Throws:

java.io.IOException - if an I/O error occurs.

See Also:

FilterInputStream.in

read

public abstract int read()
                  throws java.io.IOException

Reads the next byte of data from this input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Overrides:

read in class java.io.FilterInputStream

Returns:

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

Throws:

java.io.IOException - if an I/O error occurs.

See Also:

FilterInputStream.in

read

public final int read(byte[] b,
                      int off,
                      int len)
               throws java.io.IOException

Reads up to len bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

This method simply performs in.read(b, off, len) and returns the result.

Overrides:

read in class java.io.FilterInputStream

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 total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Throws:

java.io.IOException - if an I/O error occurs.

See Also:

FilterInputStream.in

insert

protected int insert(byte[] bytes)
              throws java.io.IOException

Pushes all of the bytes after the first one into the pushback buffer and returns the first byte, effectively inserting the bytes into the stream.

Parameters:

bytes - The bytes to insert into the stream.

Returns:

the first byte

Throws:

java.io.IOException - if something goes wrong.