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Panda Core is the core module of Panda Framework, it contains commonly used utility classes similar to apache-commons.
There is a newer version: 1.8.0
package panda.net.io;

import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/***
 * This class wraps an output 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.
 * 
 * Because of the translation process, a call to flush() will not flush the last byte
 * written if that byte was a carriage return. A call to {@link #close close() }, however, will
 * flush the carriage return.
 ***/

public final class FromNetASCIIOutputStream extends FilterOutputStream {
	private boolean __lastWasCR;

	/***
	 * Creates a FromNetASCIIOutputStream instance that wraps an existing OutputStream.
	 * 
	 * @param output The OutputStream to wrap.
	 ***/
	public FromNetASCIIOutputStream(OutputStream output) {
		super(output);
		__lastWasCR = false;
	}

	private void __write(int ch) throws IOException {
		switch (ch) {
		case '\r':
			__lastWasCR = true;
			// Don't write anything. We need to see if next one is linefeed
			break;
		case '\n':
			if (__lastWasCR) {
				out.write(FromNetASCIIInputStream._lineSeparatorBytes);
				__lastWasCR = false;
				break;
			}
			__lastWasCR = false;
			out.write('\n');
			break;
		default:
			if (__lastWasCR) {
				out.write('\r');
				__lastWasCR = false;
			}
			out.write(ch);
			break;
		}
	}

	/***
	 * Writes a byte to the stream. Note that a call to this method might not actually write a byte
	 * to the underlying stream until a subsequent character is written, from which it can be
	 * determined if a NETASCII line separator was encountered. This is transparent to the
	 * programmer and is only mentioned for completeness.
	 * 
	 * @param ch The byte to write.
	 * @exception IOException If an error occurs while writing to the underlying stream.
	 ***/
	@Override
	public synchronized void write(int ch) throws IOException {
		if (FromNetASCIIInputStream._noConversionRequired) {
			out.write(ch);
			return;
		}

		__write(ch);
	}

	/***
	 * Writes a byte array to the stream.
	 * 
	 * @param buffer The byte array to write.
	 * @exception IOException If an error occurs while writing to the underlying stream.
	 ***/
	@Override
	public synchronized void write(byte buffer[]) throws IOException {
		write(buffer, 0, buffer.length);
	}

	/***
	 * Writes a number of bytes from a byte array to the stream starting from a given offset.
	 * 
	 * @param buffer The byte array to write.
	 * @param offset The offset into the array at which to start copying data.
	 * @param length The number of bytes to write.
	 * @exception IOException If an error occurs while writing to the underlying stream.
	 ***/
	@Override
	public synchronized void write(byte buffer[], int offset, int length) throws IOException {
		if (FromNetASCIIInputStream._noConversionRequired) {
			// FilterOutputStream method is very slow.
			// super.write(buffer, offset, length);
			out.write(buffer, offset, length);
			return;
		}

		while (length-- > 0) {
			__write(buffer[offset++]);
		}
	}

	/***
	 * Closes the stream, writing all pending data.
	 * 
	 * @exception IOException If an error occurs while closing the stream.
	 ***/
	@Override
	public synchronized void close() throws IOException {
		if (FromNetASCIIInputStream._noConversionRequired) {
			super.close();
			return;
		}

		if (__lastWasCR) {
			out.write('\r');
		}
		super.close();
	}
}