1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.codec.binary;
19
20 import java.io.OutputStream;
21
22 import org.apache.commons.codec.CodecPolicy;
23 import org.apache.commons.codec.binary.BaseNCodecOutputStream.AbstractBuilder; // NOPMD: Required by ECJ (Eclipse)
24
25 /**
26 * Provides Base32 encoding in a streaming fashion (unlimited size). When encoding the default lineLength is 76 characters and the default lineEnding is CRLF,
27 * but these can be overridden by using the appropriate constructor.
28 * <p>
29 * The default behavior of the Base32OutputStream is to ENCODE, whereas the default behavior of the Base32InputStream is to DECODE. But this behavior can be
30 * overridden by using a different constructor.
31 * </p>
32 * <p>
33 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode character encodings which are
34 * compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
35 * </p>
36 * <p>
37 * <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
38 * resulting data will be incomplete/inconsistent.
39 * </p>
40 * <p>
41 * 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
42 * unused from the final character or entire characters. The default mode is lenient decoding.
43 * </p>
44 * <ul>
45 * <li>Lenient: Any trailing bits are composed into 8-bit bytes where possible. The remainder are discarded.
46 * <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
47 * character must be zero. Impossible counts of entire final characters are not allowed.
48 * </ul>
49 * <p>
50 * 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
51 * the final character. This requires that the input bytes use the same padding and alphabet as the encoder.
52 * </p>
53 *
54 * @see Base32
55 * @see <a href="https://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a>
56 * @since 1.5
57 */
58 public class Base32OutputStream extends BaseNCodecOutputStream<Base32, Base32OutputStream, Base32OutputStream.Builder> {
59
60 /**
61 * Builds instances of Base32InputStream.
62 *
63 * @since 1.20.0
64 */
65 public static class Builder extends AbstractBuilder<Base32OutputStream, Base32, Builder> {
66
67 /**
68 * Constructs a new instance.
69 */
70 public Builder() {
71 setEncode(true);
72 }
73
74 @Override
75 public Base32OutputStream get() {
76 return new Base32OutputStream(this);
77 }
78
79 @Override
80 protected Base32 newBaseNCodec() {
81 return new Base32();
82 }
83 }
84
85 /**
86 * Constructs a new Builder.
87 *
88 * @return a new Builder.
89 */
90 public static Builder builder() {
91 return new Builder();
92 }
93
94 private Base32OutputStream(final Builder builder) {
95 super(builder);
96 }
97
98 /**
99 * 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 <= 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 <= 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 <= 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 <=
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 }