    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.java 1435550 2013-01-19 14:09:52Z tn $
    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(final 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(final OutputStream out, final 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(final OutputStream out, final boolean doEncode,
    085                                  final int lineLength, final byte[] lineSeparator) {
    086            super(out, new Base64(lineLength, lineSeparator), doEncode);
    087        }
    088    }