NewlineOutputStream.java

/*
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import java.io.*;

/**
 * Convert the various newline conventions to the local platform's
 * newline convention. <p>
 *
 * This stream can be used with the Message.writeTo method to
 * generate a message that uses the local plaform's line terminator
 * for the purpose of (e.g.) saving the message to a local file.
 */
public class NewlineOutputStream extends FilterOutputStream {
    private int lastb = -1;
    private static byte[] newline;

    public NewlineOutputStream(OutputStream os) {
	super(os);
	if (newline == null) {
	    String s = System.getProperty("line.separator");
	    if (s == null || s.length() <= 0)
		s = "\n";
	    try {
		newline = s.getBytes("iso-8859-1");	// really us-ascii
	    } catch (UnsupportedEncodingException ex) {
		// should never happen
		newline = new byte[] { (byte)'\n' };
	    }
	}
    }

    public void write(int b) throws IOException {
	if (b == '\r') {
	    out.write(newline);
	} else if (b == '\n') {
	    if (lastb != '\r')
		out.write(newline);
	} else {
	    out.write(b);
	}
	lastb = b;
    }

    public void write(byte b[]) throws IOException {
	write(b, 0, b.length);
    }

    public void write(byte b[], int off, int len) throws IOException {
	for (int i = 0 ; i < len ; i++) {
	    write(b[off + i]);
	}
    }
}