1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
/*
* Base64InputStream.java February 2014
*
* Copyright (C) 2014, Niall Gallagher <niallg@users.sf.net>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package org.simpleframework.common.encode;
import java.io.IOException;
import java.io.InputStream;
/**
* The <code>Base64InputStream</code> is used to read base64 text in
* the form of a string through a conventional input stream. This is
* provided for convenience so that it is possible to encode and
* decode binary data as base64 for implementations that would
* normally use a binary format.
*
* @author Niall Gallagher
*
* @see org.simpleframework.common.encode.Base64Encoder
*/
public class Base64InputStream extends InputStream {
/**
* This is that original base64 text that is to be decoded.
*/
private char[] encoded;
/**
* This is used to accumulate the decoded text as an array.
*/
private byte[] decoded;
/**
* This is a temporary buffer used to read one byte at a time.
*/
private byte[] temp;
/**
* This is the total number of bytes that have been read.
*/
private int count;
/**
* Constructor for the <code>Base64InputStream</code> object.
* This takes an encoded string and reads it as binary data.
*
* @param source this string containing the encoded data
*/
public Base64InputStream(String source) {
this.encoded = source.toCharArray();
this.temp = new byte[1];
}
/**
* This is used to read the next byte decoded from the text. If
* the data has been fully consumed then this will return the
* standard -1.
*
* @return this returns the next octet decoded
*/
@Override
public int read() throws IOException {
int count = read(temp);
if (count == -1) {
return -1;
}
return temp[0] & 0xff;
}
/**
* This is used to read the next byte decoded from the text. If
* the data has been fully consumed then this will return the
* standard -1.
*
* @param array this is the array to decode the text to
* @param offset this is the offset to decode in to the array
* @param this is the number of bytes available to decode to
*
* @return this returns the number of octets decoded
*/
@Override
public int read(byte[] array, int offset, int length) throws IOException {
if (decoded == null) {
decoded = Base64Encoder.decode(encoded);
}
if (count >= decoded.length) {
return -1;
}
int size = Math.min(length, decoded.length - count);
if (size > 0) {
System.arraycopy(decoded, count, array, offset, size);
count += size;
}
return size;
}
/**
* This returns the original base64 text that was encoded. This
* is useful for debugging purposes to see the source data.
*
* @return this returns the original base64 text to decode
*/
@Override
public String toString() {
return new String(encoded);
}
}
|
