com.twelvemonkeys.io.enc.Base64Encoder Maven / Gradle / Ivy
/*
* Copyright (c) 2008, Harald Kuhr
* 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 the copyright holder 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 HOLDER 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.
*/
package com.twelvemonkeys.io.enc;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
/**
* {@code Encoder} implementation for standard base64 encoding.
*
* @see RFC 1421
* @see RFC 2045
*
* @see Base64Decoder
*
* @author Harald Kuhr
* @version $Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/io/enc/Base64Encoder.java#2 $
*/
public class Base64Encoder implements Encoder {
public void encode(final OutputStream stream, final ByteBuffer buffer)
throws IOException
{
// TODO: Implement
// NOTE: This is impossible, given the current spec, as we need to either:
// - buffer all data in the EncoderStream
// - or have flush/end method(s) in the Encoder
// to ensure proper end of stream handling
int length;
// TODO: Temp impl, will only work for single writes
while (buffer.hasRemaining()) {
byte a, b, c;
// if ((buffer.remaining()) > 2) {
// length = 3;
// }
// else {
// length = buffer.remaining();
// }
length = Math.min(3, buffer.remaining());
switch (length) {
case 1:
a = buffer.get();
b = 0;
stream.write(Base64Decoder.PEM_ARRAY[(a >>> 2) & 0x3F]);
stream.write(Base64Decoder.PEM_ARRAY[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]);
stream.write('=');
stream.write('=');
break;
case 2:
a = buffer.get();
b = buffer.get();
c = 0;
stream.write(Base64Decoder.PEM_ARRAY[(a >>> 2) & 0x3F]);
stream.write(Base64Decoder.PEM_ARRAY[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]);
stream.write(Base64Decoder.PEM_ARRAY[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)]);
stream.write('=');
break;
default:
a = buffer.get();
b = buffer.get();
c = buffer.get();
stream.write(Base64Decoder.PEM_ARRAY[(a >>> 2) & 0x3F]);
stream.write(Base64Decoder.PEM_ARRAY[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]);
stream.write(Base64Decoder.PEM_ARRAY[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)]);
stream.write(Base64Decoder.PEM_ARRAY[c & 0x3F]);
break;
}
}
}
}