Java example source code file (Base64Dialect.java)

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The Base64Dialect.java Java example source code

/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you 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.
 */
/*
 * Written by Robert Harder and released to the public domain, as explained at
 * http://creativecommons.org/licenses/publicdomain
 */
package io.netty.handler.codec.base64;

/**
 * Enumeration of supported Base64 dialects.
 * <p>
 * The internal lookup tables in this class has been derived from
 * <a href="http://iharder.sourceforge.net/current/java/base64/">Robert Harder's Public Domain
 * Base64 Encoder/Decoder</a>.
 */
public enum Base64Dialect {
    /**
     * Standard Base64 encoding as described in the Section 3 of
     * <a href="http://www.faqs.org/rfcs/rfc3548.html">RFC3548.
     */
    STANDARD(new byte[] {
            (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E',
            (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J',
            (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O',
            (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T',
            (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y',
            (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd',
            (byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i',
            (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n',
            (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's',
            (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x',
            (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2',
            (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7',
            (byte) '8', (byte) '9', (byte) '+', (byte) '/' },
            new byte[] {
            -9, -9, -9, -9, -9, -9,
            -9, -9, -9, // Decimal  0 -  8
            -5, -5, // Whitespace: Tab and Linefeed
            -9, -9, // Decimal 11 - 12
            -5, // Whitespace: Carriage Return
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
            -9, -9, -9, -9, -9, // Decimal 27 - 31
            -5, // Whitespace: Space
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
            62, // Plus sign at decimal 43
            -9, -9, -9, // Decimal 44 - 46
            63, // Slash at decimal 47
            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
            -9, -9, -9, // Decimal 58 - 60
            -1, // Equals sign at decimal 61
            -9, -9, -9, // Decimal 62 - 64
             0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N'
            14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z'
            -9, -9, -9, -9, -9, -9, // Decimal 91 - 96
            26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm'
            39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z'
            -9, -9, -9, -9, // Decimal 123 - 126
         /* -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 139
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 140 - 152
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 153 - 165
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 166 - 178
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 179 - 191
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 192 - 204
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 205 - 217
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 218 - 230
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 231 - 243
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9         // Decimal 244 - 255 */
            }, true),
    /**
     * Base64-like encoding that is URL-safe as described in the Section 4 of
     * <a href="http://www.faqs.org/rfcs/rfc3548.html">RFC3548.  It is
     * important to note that data encoded this way is <em>not officially
     * valid Base64, or at the very least should not be called Base64 without
     * also specifying that is was encoded using the URL-safe dialect.
     */
    URL_SAFE(new byte[] {
            (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E',
            (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J',
            (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O',
            (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T',
            (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y',
            (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd',
            (byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i',
            (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n',
            (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's',
            (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x',
            (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2',
            (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7',
            (byte) '8', (byte) '9', (byte) '-', (byte) '_' },
            new byte[] {
            -9, -9, -9, -9, -9, -9,
            -9, -9, -9, // Decimal  0 -  8
            -5, -5, // Whitespace: Tab and Linefeed
            -9, -9, // Decimal 11 - 12
            -5, // Whitespace: Carriage Return
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
            -9, -9, -9, -9, -9, // Decimal 27 - 31
            -5, // Whitespace: Space
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
            -9, // Plus sign at decimal 43
            -9, // Decimal 44
            62, // Minus sign at decimal 45
            -9, // Decimal 46
            -9, // Slash at decimal 47
            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
            -9, -9, -9, // Decimal 58 - 60
            -1, // Equals sign at decimal 61
            -9, -9, -9, // Decimal 62 - 64
             0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N'
            14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z'
            -9, -9, -9, -9, // Decimal 91 - 94
            63, // Underscore at decimal 95
            -9, // Decimal 96
            26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm'
            39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z'
            -9, -9, -9, -9, // Decimal 123 - 126
          /*-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 139
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 140 - 152
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 153 - 165
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 166 - 178
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 179 - 191
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 192 - 204
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 205 - 217
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 218 - 230
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 231 - 243
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9         // Decimal 244 - 255 */
            }, false),
    /**
     * Special "ordered" dialect of Base64 described in
     * <a href="http://www.faqs.org/qa/rfcc-1940.html">RFC1940.
     */
    ORDERED(new byte[] {
            (byte) '-', (byte) '0', (byte) '1', (byte) '2', (byte) '3',
            (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8',
            (byte) '9', (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D',
            (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I',
            (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N',
            (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S',
            (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X',
            (byte) 'Y', (byte) 'Z', (byte) '_', (byte) 'a', (byte) 'b',
            (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g',
            (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l',
            (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q',
            (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v',
            (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z' },
            new byte[] {
            -9, -9, -9, -9, -9, -9,
            -9, -9, -9, // Decimal  0 -  8
            -5, -5, // Whitespace: Tab and Linefeed
            -9, -9, // Decimal 11 - 12
            -5, // Whitespace: Carriage Return
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
            -9, -9, -9, -9, -9, // Decimal 27 - 31
            -5, // Whitespace: Space
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
            -9, // Plus sign at decimal 43
            -9, // Decimal 44
             0, // Minus sign at decimal 45
            -9, // Decimal 46
            -9, // Slash at decimal 47
             1, 2, 3, 4, 5, 6, 7, 8, 9, 10, // Numbers zero through nine
            -9, -9, -9, // Decimal 58 - 60
            -1, // Equals sign at decimal 61
            -9, -9, -9, // Decimal 62 - 64
            11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, // Letters 'A' through 'M'
            24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, // Letters 'N' through 'Z'
            -9, -9, -9, -9, // Decimal 91 - 94
            37, // Underscore at decimal 95
            -9, // Decimal 96
            38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, // Letters 'a' through 'm'
            51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, // Letters 'n' through 'z'
            -9, -9, -9, -9, // Decimal 123 - 126
         /* -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 139
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 140 - 152
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 153 - 165
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 166 - 178
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 179 - 191
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 192 - 204
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 205 - 217
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 218 - 230
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 231 - 243
            -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9         // Decimal 244 - 255 */
            }, true);

    final byte[] alphabet;
    final byte[] decodabet;
    final boolean breakLinesByDefault;

    Base64Dialect(byte[] alphabet, byte[] decodabet, boolean breakLinesByDefault) {
        this.alphabet = alphabet;
        this.decodabet = decodabet;
        this.breakLinesByDefault = breakLinesByDefault;
    }
}