org.apache.commons.net.io

Class FromNetASCIIInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

java.io.PushbackInputStream

org.apache.commons.net.io.FromNetASCIIInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public final class FromNetASCIIInputStream
extends java.io.PushbackInputStream

This class wraps an input stream, replacing all occurrences of <CR><LF> (carriage return followed by a linefeed), which is the NETASCII standard for representing a newline, with the local line separator representation. You would use this class to implement ASCII file transfers requiring conversion from NETASCII.

Field Summary

Fields

Modifier and Type	Field and Description
private int	__length
(package private) static java.lang.String	_lineSeparator
(package private) static byte[]	_lineSeparatorBytes
(package private) static boolean	_noConversionRequired

Fields inherited from class java.io.PushbackInputStream

buf, pos

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor and Description
FromNetASCIIInputStream(java.io.InputStream input) Creates a FromNetASCIIInputStream instance that wraps an existing InputStream.

Method Summary

Modifier and Type	Method and Description
private int	__read()
int	available() Returns the number of bytes that can be read without blocking EXCEPT when newline conversions have to be made somewhere within the available block of bytes.
static boolean	isConversionRequired() Returns true if the NetASCII line separator differs from the system line separator, false if they are the same.
int	read() Reads and returns the next byte in the stream.
int	read(byte[] buffer) Reads the next number of bytes from the stream into an array and returns the number of bytes read.
int	read(byte[] buffer, int offset, int length) Reads the next number of bytes from the stream into an array and returns the number of bytes read.

Methods inherited from class java.io.PushbackInputStream

close, mark, markSupported, reset, skip, unread, unread, unread

Methods inherited from class java.lang.Object

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

Field Detail

_noConversionRequired

static final boolean _noConversionRequired

_lineSeparator

static final java.lang.String _lineSeparator

_lineSeparatorBytes

static final byte[] _lineSeparatorBytes

__length

private int __length

Constructor Detail

FromNetASCIIInputStream

public FromNetASCIIInputStream(java.io.InputStream input)

Creates a FromNetASCIIInputStream instance that wraps an existing InputStream.

Parameters:

input - the stream to wrap

Method Detail

isConversionRequired

public static final boolean isConversionRequired()

Returns true if the NetASCII line separator differs from the system line separator, false if they are the same. This method is useful to determine whether or not you need to instantiate a FromNetASCIIInputStream object.

Returns:

True if the NETASCII line separator differs from the local system line separator, false if they are the same.

__read

private int __read()
            throws java.io.IOException

Throws:

java.io.IOException

read

public int read()
         throws java.io.IOException

Reads and returns the next byte in the stream. If the end of the message has been reached, returns -1. Note that a call to this method may result in multiple reads from the underlying input stream in order to convert NETASCII line separators to the local line separator format. This is transparent to the programmer and is only mentioned for completeness.

Overrides:

read in class java.io.PushbackInputStream

Returns:

The next character in the stream. Returns -1 if the end of the stream has been reached.

Throws:

java.io.IOException - If an error occurs while reading the underlying stream.

read

public int read(byte[] buffer)
         throws java.io.IOException

Reads the next number of bytes from the stream into an array and returns the number of bytes read. Returns -1 if the end of the stream has been reached.

Overrides:

read in class java.io.FilterInputStream

Parameters:

buffer - The byte array in which to store the data.

Returns:

The number of bytes read. Returns -1 if the end of the message has been reached.

Throws:

java.io.IOException - If an error occurs in reading the underlying stream.

read

public int read(byte[] buffer,
                int offset,
                int length)
         throws java.io.IOException

Reads the next number of bytes from the stream into an array and returns the number of bytes read. Returns -1 if the end of the message has been reached. The characters are stored in the array starting from the given offset and up to the length specified.

Overrides:

read in class java.io.PushbackInputStream

Parameters:

buffer - The byte array in which to store the data.

offset - The offset into the array at which to start storing data.

length - The number of bytes to read.

Returns:

The number of bytes read. Returns -1 if the end of the stream has been reached.

Throws:

java.io.IOException - If an error occurs while reading the underlying stream.

available

public int available()
              throws java.io.IOException

Returns the number of bytes that can be read without blocking EXCEPT when newline conversions have to be made somewhere within the available block of bytes. In other words, you really should not rely on the value returned by this method if you are trying to avoid blocking.

Overrides:

available in class java.io.PushbackInputStream

Throws:

java.io.IOException