src-main.org.awakefw.file.api.util.Base64 Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of awake-file Show documentation
Show all versions of awake-file Show documentation
Awake FILE is a secure Open Source framework that allows to program very easily file uploads/downloads and RPC through http. File transfers include
powerful features like file chunking and automatic recovery mechanism.
Security has been taken into account from the design: server side allows
to specify strong security rules in order to protect the files and to secure the RPC calls.
/*
* This file is part of Awake FILE.
* Awake FILE: Easy file upload & download over HTTP with Java.
* Copyright (C) 2014, KawanSoft SAS
* (http://www.kawansoft.com). All rights reserved.
*
* Awake FILE is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Awake FILE is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Any modifications to this file must keep this entire header
* intact.
*/
/*
* @(#)Base64.java 1.3 01/12/03
*
* Copyright 2002 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package org.awakefw.file.api.util;
import java.util.prefs.Preferences;
/**
* Static methods for translating Base64 encoded strings to byte arrays and
* vice-versa.
*
* @author Josh Bloch
* @version 1.3, 12/03/01
* @see Preferences
* @since 1.4
*/
public class Base64 {
/**
* Translates the specified byte array into a Base64 string as per
* Preferences.put(byte[]).
*/
public static String byteArrayToBase64(byte[] a) {
return byteArrayToBase64(a, false);
}
/**
* Translates the specified byte array into an "aternate representation"
* Base64 string. This non-standard variant uses an alphabet that does not
* contain the uppercase alphabetic characters, which makes it suitable for
* use in situations where case-folding occurs.
*/
static String byteArrayToAltBase64(byte[] a) {
return byteArrayToBase64(a, true);
}
private static String byteArrayToBase64(byte[] a, boolean alternate) {
int aLen = a.length;
int numFullGroups = aLen / 3;
int numBytesInPartialGroup = aLen - 3 * numFullGroups;
int resultLen = 4 * ((aLen + 2) / 3);
StringBuffer result = new StringBuffer(resultLen);
char[] intToAlpha = (alternate ? intToAltBase64 : intToBase64);
// Translate all full groups from byte array elements to Base64
int inCursor = 0;
for (int i = 0; i < numFullGroups; i++) {
int byte0 = a[inCursor++] & 0xff;
int byte1 = a[inCursor++] & 0xff;
int byte2 = a[inCursor++] & 0xff;
result.append(intToAlpha[byte0 >> 2]);
result.append(intToAlpha[(byte0 << 4) & 0x3f | (byte1 >> 4)]);
result.append(intToAlpha[(byte1 << 2) & 0x3f | (byte2 >> 6)]);
result.append(intToAlpha[byte2 & 0x3f]);
}
// Translate partial group if present
if (numBytesInPartialGroup != 0) {
int byte0 = a[inCursor++] & 0xff;
result.append(intToAlpha[byte0 >> 2]);
if (numBytesInPartialGroup == 1) {
result.append(intToAlpha[(byte0 << 4) & 0x3f]);
result.append("==");
} else {
// assert numBytesInPartialGroup == 2;
int byte1 = a[inCursor++] & 0xff;
result.append(intToAlpha[(byte0 << 4) & 0x3f | (byte1 >> 4)]);
result.append(intToAlpha[(byte1 << 2) & 0x3f]);
result.append('=');
}
}
// assert inCursor == a.length;
// assert result.length() == resultLen;
return result.toString();
}
/**
* This array is a lookup table that translates 6-bit positive integer index
* values into their "Base64 Alphabet" equivalents as specified in Table 1
* of RFC 2045.
*/
private static final char intToBase64[] = { 'A', 'B', 'C', 'D', 'E', 'F',
'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',
'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', '+', '/' };
/**
* This array is a lookup table that translates 6-bit positive integer index
* values into their "Alternate Base64 Alphabet" equivalents. This is NOT
* the real Base64 Alphabet as per in Table 1 of RFC 2045. This alternate
* alphabet does not use the capital letters. It is designed for use in
* environments where "case folding" occurs.
*/
private static final char intToAltBase64[] = { '!', '"', '#', '$', '%',
'&', '\'', '(', ')', ',', '-', '.', ':', ';', '<', '>', '@', '[',
']', '^', '`', '_', '{', '|', '}', '~', 'a', 'b', 'c', 'd', 'e',
'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r',
's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4',
'5', '6', '7', '8', '9', '+', '?' };
/**
* Translates the specified Base64 string (as per Preferences.get(byte[]))
* into a byte array.
*
* @throw IllegalArgumentException if s is not a valid Base64
* string.
*/
public static byte[] base64ToByteArray(String s) {
return base64ToByteArray(s, false);
}
/**
* Translates the specified "aternate representation" Base64 string into a
* byte array.
*
* @throw IllegalArgumentException or ArrayOutOfBoundsException if
* s is not a valid alternate representation Base64 string.
*/
static byte[] altBase64ToByteArray(String s) {
return base64ToByteArray(s, true);
}
private static byte[] base64ToByteArray(String s, boolean alternate) {
byte[] alphaToInt = (alternate ? altBase64ToInt : base64ToInt);
int sLen = s.length();
int numGroups = sLen / 4;
if (4 * numGroups != sLen)
throw new IllegalArgumentException(
"String length must be a multiple of four.");
int missingBytesInLastGroup = 0;
int numFullGroups = numGroups;
if (sLen != 0) {
if (s.charAt(sLen - 1) == '=') {
missingBytesInLastGroup++;
numFullGroups--;
}
if (s.charAt(sLen - 2) == '=')
missingBytesInLastGroup++;
}
byte[] result = new byte[3 * numGroups - missingBytesInLastGroup];
// Translate all full groups from base64 to byte array elements
int inCursor = 0, outCursor = 0;
for (int i = 0; i < numFullGroups; i++) {
int ch0 = base64toInt(s.charAt(inCursor++), alphaToInt);
int ch1 = base64toInt(s.charAt(inCursor++), alphaToInt);
int ch2 = base64toInt(s.charAt(inCursor++), alphaToInt);
int ch3 = base64toInt(s.charAt(inCursor++), alphaToInt);
result[outCursor++] = (byte) ((ch0 << 2) | (ch1 >> 4));
result[outCursor++] = (byte) ((ch1 << 4) | (ch2 >> 2));
result[outCursor++] = (byte) ((ch2 << 6) | ch3);
}
// Translate partial group, if present
if (missingBytesInLastGroup != 0) {
int ch0 = base64toInt(s.charAt(inCursor++), alphaToInt);
int ch1 = base64toInt(s.charAt(inCursor++), alphaToInt);
result[outCursor++] = (byte) ((ch0 << 2) | (ch1 >> 4));
if (missingBytesInLastGroup == 1) {
int ch2 = base64toInt(s.charAt(inCursor++), alphaToInt);
result[outCursor++] = (byte) ((ch1 << 4) | (ch2 >> 2));
}
}
// assert inCursor == s.length()-missingBytesInLastGroup;
// assert outCursor == result.length;
return result;
}
/**
* Translates the specified character, which is assumed to be in the
* "Base 64 Alphabet" into its equivalent 6-bit positive integer.
*
* @throw IllegalArgumentException or ArrayOutOfBoundsException if c is not
* in the Base64 Alphabet.
*/
private static int base64toInt(char c, byte[] alphaToInt) {
int result = alphaToInt[c];
if (result < 0)
throw new IllegalArgumentException("Illegal character " + c);
return result;
}
/**
* This array is a lookup table that translates unicode characters drawn
* from the "Base64 Alphabet" (as specified in Table 1 of RFC 2045) into
* their 6-bit positive integer equivalents. Characters that are not in the
* Base64 alphabet but fall within the bounds of the array are translated to
* -1.
*/
private static final byte base64ToInt[] = { -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1,
-1, -1, -1, -1, -1, -1, 0, 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, -1, -1, -1, -1,
-1, -1, 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 };
/**
* This array is the analogue of base64ToInt, but for the nonstandard
* variant that avoids the use of uppercase alphabetic characters.
*/
private static final byte altBase64ToInt[] = { -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, -1,
62, 9, 10, 11, -1, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 12, 13,
14, -1, 15, 63, 16, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 17, -1, 18,
19, 21, 20, 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, 22, 23, 24, 25 };
/*
* public static void main(String args[]) { int numRuns =
* Integer.parseInt(args[0]); int numBytes = Integer.parseInt(args[1]);
* java.util.Random rnd = new java.util.Random(); for (int i=0; i© 2015 - 2024 Weber Informatics LLC | Privacy Policy