/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common
* Development and Distribution License("CDDL") (collectively, the
* "License"). You may not use this file except in compliance with the
* License. You can obtain a copy of the License at
* http://www.netbeans.org/cddl-gplv2.html
* or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
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* Notice in each file and include the License file at
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* particular file as subject to the "Classpath" exception as provided
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* accompanied this code. If applicable, add the following below the
* License Header, with the fields enclosed by brackets [] replaced by
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* Contributor(s):
*
* The Original Software is NetBeans. The Initial Developer of the Original
* Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
* Microsystems, Inc. All Rights Reserved.
*
* If you wish your version of this file to be governed by only the CDDL
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* "[Contributor] elects to include this software in this distribution
* under the [CDDL or GPL Version 2] license." If you do not indicate a
* single choice of license, a recipient has the option to distribute
* your version of this file under either the CDDL, the GPL Version 2 or
* to extend the choice of license to its licensees as provided above.
* However, if you add GPL Version 2 code and therefore, elected the GPL
* Version 2 license, then the option applies only if the new code is
* made subject to such option by the copyright holder.
*/
/** This class provides Base64 encoding/decoding.
*/
public class Base64
{
private Base64()
{
//Avoid instantiation of this class
}
/** Encodes datas using base64 encoding.
* @param abyte0 data for encoding
* @return encoded string
*/
static String encode(final byte abyte0[])
{
final StringBuffer stringbuffer = new StringBuffer();
for(int i = 0; i < abyte0.length; i += 3)
stringbuffer.append(encodeBlock(abyte0, i));
return stringbuffer.toString();
}
private static char[] encodeBlock(final byte abyte0[], final int i)
{
int j = 0;
final int k = abyte0.length - i - 1;
final int l = k < 2 ? k : 2;
for(int i1 = 0; i1 <= l; i1++)
{
final byte byte0 = abyte0[i + i1];
final int j1 = byte0 >= 0 ? ((int) (byte0)) : byte0 + 256;
j += j1 << 8 * (2 - i1);
}
char ac[] = new char[4];
for(int k1 = 0; k1 < 4; k1++)
{
final int l1 = j >>> 6 * (3 - k1) & 0x3f;
ac[k1] = getChar(l1);
}
if(k < 1)
ac[2] = '=';
if(k < 2)
ac[3] = '=';
return ac;
}
private static char getChar(final int i)
{
if(i >= 0 && i <= 25)
return (char)(65 + i);
if(i >= 26 && i <= 51)
return (char)(97 + (i - 26));
if(i >= 52 && i <= 61)
return (char)(48 + (i - 52));
if(i == 62)
return '+';
return i != 63 ? '?' : '/';
}
/** Decode string using Base64 encoding.
* @param s string for decoding
* @return decoded data
*/
static byte[] decode(final String s)
{
if (s.length() == 0) return new byte[0];
int i = 0;
for(int j = s.length() - 1; j > 0 && s.charAt(j) == '='; j--)
i++;
final int k = (s.length() * 6) / 8 - i;
byte abyte0[] = new byte[k];
int l = 0;
for(int i1 = 0; i1 < s.length(); i1 += 4)
{
final int j1 = (getValue(s.charAt(i1)) << 18) + (getValue(s.charAt(i1 + 1)) << 12) + (getValue(s.charAt(i1 + 2)) << 6) + getValue(s.charAt(i1 + 3));
for(int k1 = 0; k1 < 3 && l + k1 < abyte0.length; k1++)
abyte0[l + k1] = (byte)(j1 >> 8 * (2 - k1) & 0xff);
l += 3;
}
return abyte0;
}
private static int getValue(final char c)
{
if(c >= 'A' && c <= 'Z')
return c - 65;
if(c >= 'a' && c <= 'z')
return (c - 97) + 26;
if(c >= '0' && c <= '9')
return (c - 48) + 52;
if(c == '+')
return 62;
if(c == '/')
return 63;
return c != '=' ? -1 : 0;
}
}