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 * http://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.InputStream;
21
22 /**
23 * Provides Base64 encoding and decoding in a streaming fashion (unlimited size). When encoding the default lineLength
24 * is 76 characters and the default lineEnding is CRLF, but these can be overridden by using the appropriate
25 * constructor.
26 * <p>
27 * The default behaviour of the Base64InputStream is to DECODE, whereas the default behaviour of the Base64OutputStream
28 * is to ENCODE, but this behaviour can be overridden by using a different constructor.
29 * </p>
30 * <p>
31 * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose
32 * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein.
33 * </p>
34 * <p>
35 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode
36 * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
37 * </p>
38 *
39 * @version $Id: Base64InputStream.java 1634429 2014-10-27 01:08:36Z ggregory $
40 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
41 * @since 1.4
42 */
43 public class Base64InputStream extends BaseNCodecInputStream {
44
45 /**
46 * Creates a Base64InputStream such that all data read is Base64-decoded from the original provided InputStream.
47 *
48 * @param in
49 * InputStream to wrap.
50 */
51 public Base64InputStream(final InputStream in) {
52 this(in, false);
53 }
54
55 /**
56 * Creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original
57 * provided InputStream.
58 *
59 * @param in
60 * InputStream to wrap.
61 * @param doEncode
62 * true if we should encode all data read from us, false if we should decode.
63 */
64 public Base64InputStream(final InputStream in, final boolean doEncode) {
65 super(in, new Base64(false), doEncode);
66 }
67
68 /**
69 * Creates a Base64InputStream such that all data read is either Base64-encoded or Base64-decoded from the original
70 * provided InputStream.
71 *
72 * @param in
73 * InputStream to wrap.
74 * @param doEncode
75 * true if we should encode all data read from us, false if we should decode.
76 * @param lineLength
77 * If doEncode is true, each line of encoded data will contain lineLength characters (rounded down to
78 * nearest multiple of 4). If lineLength <= 0, the encoded data is not divided into lines. If doEncode
79 * is false, lineLength is ignored.
80 * @param lineSeparator
81 * If doEncode is true, each line of encoded data will be terminated with this byte sequence (e.g. \r\n).
82 * If lineLength <= 0, the lineSeparator is not used. If doEncode is false lineSeparator is ignored.
83 */
84 public Base64InputStream(final InputStream in, final boolean doEncode,
85 final int lineLength, final byte[] lineSeparator) {
86 super(in, new Base64(lineLength, lineSeparator), doEncode);
87 }
88 }