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1
38 package com.gargoylesoftware.htmlunit;
39
40 import java.io.UnsupportedEncodingException  ;
41
42
49 public final class Base64 {
50
51 private static final byte[] ENCODING_TABLE;
52
53 private static final byte PADDING_BYTE;
54
55 static {
56 final String table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
57 try {
58 ENCODING_TABLE = table.getBytes( "ISO-8859-1" );
59 PADDING_BYTE = "=".getBytes( "ISO-8859-1" )[0];
60 }
61 catch( final UnsupportedEncodingException e ) {
62 throw new IllegalStateException (
63 "Theoretically impossible: ISO-8859-1 (us-ascii) is not a supported encoding" );
64 }
65
66 if( ENCODING_TABLE.length != 64 ) {
67 throw new IllegalStateException ( "Encoding table doesn't contain 64 values" );
68 }
69 }
70
71
72 private Base64() {
73 }
74
75
76
82 public static String encode( final String input ) {
83 try {
84 return encode( input, "ISO-8859-1" );
85 }
86 catch( final UnsupportedEncodingException e ) {
87 throw new IllegalStateException (
88 "Theoretically impossible: ISO-8859-1 (us-ascii) is not a supported encoding" );
89 }
90 }
91
92
93
101 public static String encode( final String input, final String characterEncoding )
102 throws UnsupportedEncodingException {
103
104 return new String ( encode( input.getBytes( characterEncoding ) ), characterEncoding );
105 }
106
107
108
114 public static byte[] encode( final byte[] array ) {
115 final int paddingCharCount = ( 3 - ( array.length % 3 ) ) % 3;
116
117 final byte[] input;
118
119 if( paddingCharCount == 0 ) {
120 input = array;
121 }
122 else {
123 input = new byte[array.length + paddingCharCount];
124 System.arraycopy( array, 0, input, 0, array.length );
125 }
126
127 final byte output[] = new byte[( input.length * 4 / 3 )];
128 int outputIndex = 0;
129
130 byte byte1;
131 byte byte2;
132 byte byte3;
133
134 for( int i = 0; i < input.length; i += 3 ) {
135 byte1 = input[i];
136 byte2 = input[i + 1];
137 byte3 = input[i + 2];
138
139 output[outputIndex++] = ENCODING_TABLE[( byte1 & 0xFC ) >>> 2];
140 output[outputIndex++] = ENCODING_TABLE[( ( byte1 & 0x03 ) << 4 )
141 | ( ( byte2 & 0xF0 ) >>> 4 )];
142 output[outputIndex++] = ENCODING_TABLE[( ( byte2 & 0x0F ) << 2 )
143 | ( ( byte3 & 0xC0 ) >>> 6 )];
144 output[outputIndex++] = ENCODING_TABLE[byte3 & 0x3F];
145 }
146
147 if( paddingCharCount > 1 ) {
148 output[--outputIndex] = PADDING_BYTE;
149 }
150 if( paddingCharCount > 0 ) {
151 output[--outputIndex] = PADDING_BYTE;
152 }
153
154 return output;
155 }
156 }
157
158 |
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