/* AbstractPreferences -- Partial implementation of a Preference node
Copyright (C) 2001, 2003, 2004, 2006 Free Software Foundation, Inc.
This file is part of GNU Classpath.
GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU Classpath 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.
Linking this library statically or dynamically with other modules is
making a combined work based on this library. Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.
As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module. An independent module is a module which is not derived from
or based on this library. If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so. If you do not wish to do so, delete this
exception statement from your version. */
package freemind.main;
import java.io.ByteArrayOutputStream;
/**
* Partial implementation of a Preference node.
*
* @since 1.4
* @author Mark Wielaard (mark@klomp.org)
*
* 22.3.2008: FC: Changed name from AbstractPreferences to the current,
* Removed all but base64 coding.
*/
public class Base64Coding {
private static java.util.logging.Logger logger = null;
static {
logger = freemind.main.Resources.getInstance()
.getLogger("Base64Coding");
}
/**
* Helper method for decoding a Base64 string as an byte array. Returns null
* on encoding error. This method does not allow any other characters
* present in the string then the 65 special base64 chars.
*/
public static byte[] decode64(String s) {
ByteArrayOutputStream bs = new ByteArrayOutputStream(
(s.length() / 4) * 3);
char[] c = new char[s.length()];
s.getChars(0, s.length(), c, 0);
// Convert from base64 chars
int endchar = -1;
for (int j = 0; j < c.length && endchar == -1; j++) {
if (c[j] >= 'A' && c[j] <= 'Z') {
c[j] -= 'A';
} else if (c[j] >= 'a' && c[j] <= 'z') {
c[j] = (char) (c[j] + 26 - 'a');
} else if (c[j] >= '0' && c[j] <= '9') {
c[j] = (char) (c[j] + 52 - '0');
} else if (c[j] == '+') {
c[j] = 62;
} else if (c[j] == '/') {
c[j] = 63;
} else if (c[j] == '=') {
endchar = j;
} else {
logger.severe("Found illegal character in base64 coding: '"
+ c[j] + "'");
return null; // encoding exception
}
}
int remaining = endchar == -1 ? c.length : endchar;
int i = 0;
while (remaining > 0) {
// Four input chars (6 bits) are decoded as three bytes as
// 000000 001111 111122 222222
byte b0 = (byte) (c[i] << 2);
if (remaining >= 2) {
b0 += (c[i + 1] & 0x30) >> 4;
}
bs.write(b0);
if (remaining >= 3) {
byte b1 = (byte) ((c[i + 1] & 0x0F) << 4);
b1 += (byte) ((c[i + 2] & 0x3C) >> 2);
bs.write(b1);
}
if (remaining >= 4) {
byte b2 = (byte) ((c[i + 2] & 0x03) << 6);
b2 += c[i + 3];
bs.write(b2);
}
i += 4;
remaining -= 4;
}
return bs.toByteArray();
}
/**
* Helper method for encoding an array of bytes as a Base64 String.
*/
public static String encode64(byte[] b) {
StringBuffer sb = new StringBuffer((b.length / 3) * 4);
int i = 0;
int remaining = b.length;
char c[] = new char[4];
while (remaining > 0) {
// Three input bytes are encoded as four chars (6 bits) as
// 00000011 11112222 22333333
c[0] = (char) ((b[i] & 0xFC) >> 2);
c[1] = (char) ((b[i] & 0x03) << 4);
if (remaining >= 2) {
c[1] += (char) ((b[i + 1] & 0xF0) >> 4);
c[2] = (char) ((b[i + 1] & 0x0F) << 2);
if (remaining >= 3) {
c[2] += (char) ((b[i + 2] & 0xC0) >> 6);
c[3] = (char) (b[i + 2] & 0x3F);
} else {
c[3] = 64;
}
} else {
c[2] = 64;
c[3] = 64;
}
// Convert to base64 chars
for (int j = 0; j < 4; j++) {
if (c[j] < 26) {
c[j] += 'A';
} else if (c[j] < 52) {
c[j] = (char) (c[j] - 26 + 'a');
} else if (c[j] < 62) {
c[j] = (char) (c[j] - 52 + '0');
} else if (c[j] == 62) {
c[j] = '+';
} else if (c[j] == 63) {
c[j] = '/';
} else {
c[j] = '=';
}
}
sb.append(c);
i += 3;
remaining -= 3;
}
return sb.toString();
}
}