001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.codec.binary;
019
020 import java.io.OutputStream;
021
022 /**
023 * Provides Base64 encoding and decoding in a streaming fashion (unlimited size). When encoding the default lineLength
024 * is 76 characters and the default lineEnding is CRLF, but these can be overridden by using the appropriate
025 * constructor.
026 * <p>
027 * The default behaviour of the Base64OutputStream is to ENCODE, whereas the default behaviour of the Base64InputStream
028 * is to DECODE. But this behaviour can be overridden by using a different constructor.
029 * </p>
030 * <p>
031 * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose
032 * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein.
033 * </p>
034 * <p>
035 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode
036 * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
037 * </p>
038 *
039 * @version $Id: Base64OutputStream.html 889935 2013-12-11 05:05:13Z ggregory $
040 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
041 * @since 1.4
042 */
043 public class Base64OutputStream extends BaseNCodecOutputStream {
044
045 /**
046 * Creates a Base64OutputStream such that all data written is Base64-encoded to the original provided OutputStream.
047 *
048 * @param out
049 * OutputStream to wrap.
050 */
051 public Base64OutputStream(OutputStream out) {
052 this(out, true);
053 }
054
055 /**
056 * Creates a Base64OutputStream such that all data written is either Base64-encoded or Base64-decoded to the
057 * original provided OutputStream.
058 *
059 * @param out
060 * OutputStream to wrap.
061 * @param doEncode
062 * true if we should encode all data written to us, false if we should decode.
063 */
064 public Base64OutputStream(OutputStream out, boolean doEncode) {
065 super(out,new Base64(false), doEncode);
066 }
067
068 /**
069 * Creates a Base64OutputStream such that all data written is either Base64-encoded or Base64-decoded to the
070 * original provided OutputStream.
071 *
072 * @param out
073 * OutputStream to wrap.
074 * @param doEncode
075 * true if we should encode all data written to us, false if we should decode.
076 * @param lineLength
077 * If doEncode is true, each line of encoded data will contain lineLength characters (rounded down to
078 * nearest multiple of 4). If lineLength <=0, the encoded data is not divided into lines. If doEncode is
079 * false, lineLength is ignored.
080 * @param lineSeparator
081 * If doEncode is true, each line of encoded data will be terminated with this byte sequence (e.g. \r\n).
082 * If lineLength <= 0, the lineSeparator is not used. If doEncode is false lineSeparator is ignored.
083 */
084 public Base64OutputStream(OutputStream out, boolean doEncode, int lineLength, byte[] lineSeparator) {
085 super(out, new Base64(lineLength, lineSeparator), doEncode);
086 }
087 }