Source code
Description: source: package: org.apache.commons.codec.binary, class: Base58OutputStream, class: Builder

    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
    022/**
    023 * Provides Base58 encoding in a streaming fashion (unlimited size). When encoding the default lineLength is 76 characters and the default lineEnding is CRLF,
    024 * but these can be overridden by using the appropriate constructor.
    025 * <p>
    026 * The default behavior of the Base58OutputStream is to ENCODE, whereas the default behavior of the Base58InputStream is to DECODE. But this behavior can be
    027 * overridden by using a different constructor.
    028 * </p>
    029 * <p>
    030 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode character encodings which are
    031 * compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
    032 * </p>
    033 * <p>
    034 * <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
    035 * resulting data will be incomplete/inconsistent.
    036 * </p>
    037 * <p>
    038 * 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
    039 * unused from the final character or entire characters. The default mode is lenient decoding.
    040 * </p>
    041 * <ul>
    042 * <li>Lenient: Any trailing bits are composed into 8-bit bytes where possible. The remainder are discarded.</li>
    043 * <li>Strict: The decoding will throw an {@link IllegalArgumentException} if trailing bits are not part of a valid encoding. Any unused bits from the final
    044 * character must be zero. Impossible counts of entire final characters are not allowed.</li>
    045 * </ul>
    046 * <p>
    047 * 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
    048 * the final character. This requires that the input bytes use the same padding and alphabet as the encoder.
    049 * </p>
    050 *
    051 * @see Base58
    052 * @see <a href="https://datatracker.ietf.org/doc/html/draft-msporny-base58-03">The Base58 Encoding Scheme draft-msporny-base58-03</a>
    053 * @since 1.22.0
    054 */
    055public class Base58OutputStream extends BaseNCodecOutputStream<Base58, Base58OutputStream, Base58OutputStream.Builder> {
    056
    057    /**
    058     * Builds instances of Base58OutputStream.
    059     */
    060    public static class Builder extends BaseNCodecOutputStream.AbstractBuilder<Base58OutputStream, Base58, Builder> {
    061
    062        /**
    063         * Constructs a new instance.
    064         */
    065        public Builder() {
    066            setEncode(true);
    067        }
    068
    069        /**
    070         * Builds a new Base58OutputStream instance with the configured settings.
    071         *
    072         * @return A new Base58OutputStream.
    073         */
    074        @Override
    075        public Base58OutputStream get() {
    076            return new Base58OutputStream(this);
    077        }
    078
    079        /**
    080         * Creates a new Base58 codec instance.
    081         *
    082         * @return A new Base58 codec.
    083         */
    084        @Override
    085        protected Base58 newBaseNCodec() {
    086            return new Base58();
    087        }
    088    }
    089
    090    /**
    091     * Constructs a new Builder.
    092     *
    093     * @return A new Builder.
    094     */
    095    public static Builder builder() {
    096        return new Builder();
    097    }
    098
    099    private Base58OutputStream(final Builder builder) {
    100        super(builder);
    101    }
    102
    103    /**
    104     * Constructs a Base58OutputStream such that all data written is Base58-encoded to the original provided OutputStream.
    105     *
    106     * @param outputStream OutputStream to wrap.
    107     */
    108    public Base58OutputStream(final OutputStream outputStream) {
    109        this(builder().setOutputStream(outputStream));
    110    }
    111
    112}