Java tutorial
/* * 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</a>. */ 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, -9 // Decimal 123 - 127 /* -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 128 - 140 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 141 - 153 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 154 - 166 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 167 - 179 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 180 - 192 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 193 - 205 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 206 - 218 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 219 - 231 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 232 - 244 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 245 - 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</a>. It is * important to note that data encoded this way is <em>not</em> 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, -9, // Decimal 123 - 127 /* -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 128 - 140 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 141 - 153 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 154 - 166 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 167 - 179 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 180 - 192 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 193 - 205 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 206 - 218 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 219 - 231 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 232 - 244 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 245 - 255 */ }, false), /** * Special "ordered" dialect of Base64 described in * <a href="http://www.faqs.org/qa/rfcc-1940.html">RFC1940</a>. */ 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, -9 // Decimal 123 - 127 /* -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 128 - 140 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 141 - 153 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 154 - 166 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 167 - 179 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 180 - 192 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 193 - 205 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 206 - 218 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 219 - 231 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 232 - 244 -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 245 - 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; } }