    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 *      https://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
    018package org.apache.commons.codec.binary;
    019
    020import java.io.OutputStream;
    021
    022import org.apache.commons.codec.CodecPolicy;
    023import org.apache.commons.codec.binary.BaseNCodecOutputStream.AbstractBuilder; // NOPMD: Required by ECJ (Eclipse)
    024
    025/**
    026 * Provides Base32 encoding in a streaming fashion (unlimited size). When encoding the default lineLength is 76 characters and the default lineEnding is CRLF,
    027 * but these can be overridden by using the appropriate constructor.
    028 * <p>
    029 * The default behavior of the Base32OutputStream is to ENCODE, whereas the default behavior of the Base32InputStream is to DECODE. But this behavior can be
    030 * overridden by using a different constructor.
    031 * </p>
    032 * <p>
    033 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode character encodings which are
    034 * compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
    035 * </p>
    036 * <p>
    037 * <strong>Note:</strong> It is mandatory to close the stream after the last byte has been written to it, otherwise the final padding will be omitted and the
    038 * resulting data will be incomplete/inconsistent.
    039 * </p>
    040 * <p>
    041 * You can set the decoding behavior when the input bytes contain leftover trailing bits that cannot be created by a valid encoding. These can be bits that are
    042 * unused from the final character or entire characters. The default mode is lenient decoding.
    043 * </p>
    044 * <ul>
    045 * <li>Lenient: Any trailing bits are composed into 8-bit bytes where possible. The remainder are discarded.
    046 * <li>Strict: The decoding will raise an {@link IllegalArgumentException} if trailing bits are not part of a valid encoding. Any unused bits from the final
    047 * character must be zero. Impossible counts of entire final characters are not allowed.
    048 * </ul>
    049 * <p>
    050 * When strict decoding is enabled it is expected that the decoded bytes will be re-encoded to a byte array that matches the original, i.e. no changes occur on
    051 * the final character. This requires that the input bytes use the same padding and alphabet as the encoder.
    052 * </p>
    053 *
    054 * @see Base32
    055 * @see <a href="https://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a>
    056 * @since 1.5
    057 */
    058public class Base32OutputStream extends BaseNCodecOutputStream<Base32, Base32OutputStream, Base32OutputStream.Builder> {
    059
    060    /**
    061     * Builds instances of Base32InputStream.
    062     *
    063     * @since 1.20.0
    064     */
    065    public static class Builder extends AbstractBuilder<Base32OutputStream, Base32, Builder> {
    066
    067        /**
    068         * Constructs a new instance.
    069         */
    070        public Builder() {
    071            setEncode(true);
    072        }
    073
    074        @Override
    075        public Base32OutputStream get() {
    076            return new Base32OutputStream(this);
    077        }
    078
    079        @Override
    080        protected Base32 newBaseNCodec() {
    081            return new Base32();
    082        }
    083    }
    084
    085    /**
    086     * Constructs a new Builder.
    087     *
    088     * @return a new Builder.
    089     */
    090    public static Builder builder() {
    091        return new Builder();
    092    }
    093
    094    private Base32OutputStream(final Builder builder) {
    095        super(builder);
    096    }
    097
    098    /**
    099     * Constructs a Base32OutputStream such that all data written is Base32-encoded to the original provided OutputStream.
    100     *
    101     * @param outputStream OutputStream to wrap.
    102     */
    103    public Base32OutputStream(final OutputStream outputStream) {
    104        this(builder().setOutputStream(outputStream));
    105    }
    106
    107    /**
    108     * Constructs a Base32OutputStream such that all data written is either Base32-encoded or Base32-decoded to the original provided OutputStream.
    109     *
    110     * @param outputStream OutputStream to wrap.
    111     * @param encode     true if we should encode all data written to us, false if we should decode.
    112     * @deprecated Use {@link #builder()} and {@link Builder}.
    113     */
    114    @Deprecated
    115    public Base32OutputStream(final OutputStream outputStream, final boolean encode) {
    116        super(builder().setOutputStream(outputStream).setEncode(encode));
    117    }
    118
    119    /**
    120     * Constructs a Base32OutputStream such that all data written is either Base32-encoded or Base32-decoded to the original provided OutputStream.
    121     *
    122     * @param outputStream  OutputStream to wrap.
    123     * @param encode      true if we should encode all data written to us, false if we should decode.
    124     * @param lineLength    If doEncode is true, each line of encoded data will contain lineLength characters (rounded down to the nearest multiple of 4). If
    125     *                      lineLength &lt;= 0, the encoded data is not divided into lines. If doEncode is false, lineLength is ignored.
    126     * @param lineSeparator If doEncode is true, each line of encoded data will be terminated with this byte sequence (for example \r\n). If lineLength &lt;= 0,
    127     *                      the lineSeparator is not used. If doEncode is false lineSeparator is ignored.
    128     * @deprecated Use {@link #builder()} and {@link Builder}.
    129     */
    130    @Deprecated
    131    public Base32OutputStream(final OutputStream outputStream, final boolean encode, final int lineLength, final byte[] lineSeparator) {
    132        super(builder().setOutputStream(outputStream).setEncode(encode)
    133                .setBaseNCodec(Base32.builder().setLineLength(lineLength).setLineSeparator(lineSeparator).get()));
    134    }
    135
    136    /**
    137     * Constructs a Base32OutputStream such that all data written is either Base32-encoded or Base32-decoded to the original provided OutputStream.
    138     *
    139     * @param outputStream   OutputStream to wrap.
    140     * @param encode       true if we should encode all data written to us, false if we should decode.
    141     * @param lineLength     If doEncode is true, each line of encoded data will contain lineLength characters (rounded down to the nearest multiple of 4). If
    142     *                       lineLength &lt;= 0, the encoded data is not divided into lines. If doEncode is false, lineLength is ignored.
    143     * @param lineSeparator  If doEncode is true, each line of encoded data will be terminated with this byte sequence (for example \r\n). If lineLength &lt;=
    144     *                       0, the lineSeparator is not used. If doEncode is false lineSeparator is ignored.
    145     * @param decodingPolicy The decoding policy.
    146     * @since 1.15
    147     * @deprecated Use {@link #builder()} and {@link Builder}.
    148     */
    149    @Deprecated
    150    public Base32OutputStream(final OutputStream outputStream, final boolean encode, final int lineLength, final byte[] lineSeparator,
    151            final CodecPolicy decodingPolicy) {
    152        super(builder().setOutputStream(outputStream).setEncode(encode)
    153                .setBaseNCodec(Base32.builder().setLineLength(lineLength).setLineSeparator(lineSeparator).setDecodingPolicy(decodingPolicy).get()));
    154    }
    155}