org.apache.commons.net.io

Class FromNetASCIIInputStream


public final class FromNetASCIIInputStream
extends 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.

Author:
Daniel F. Savarese

Constructor Summary

FromNetASCIIInputStream(InputStream input)
Creates a FromNetASCIIInputStream instance that wraps an existing InputStream.

Method Summary

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(buffer[] )
Reads the next number of bytes from the stream into an array and returns the number of bytes read.
int
read(buffer[] , int offset, int length)
Reads the next number of bytes from the stream into an array and returns the number of bytes read.

Constructor Details

FromNetASCIIInputStream

public FromNetASCIIInputStream(InputStream input)
Creates a FromNetASCIIInputStream instance that wraps an existing InputStream.

Method Details

available

public int available()
            throws 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.

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

public int read()
            throws 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.

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

read

public int read(buffer[] )
            throws 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.

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

read

public int read(buffer[] ,
                int offset,
                int length)
            throws 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.

Parameters:
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.