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PlantUML is a component that allows to quickly write :
* sequence diagram,
* use case diagram,
* class diagram,
* activity diagram,
* component diagram,
* state diagram
* object diagram
/* ========================================================================
* PlantUML : a free UML diagram generator
* ========================================================================
*
* (C) Copyright 2009-2013, Arnaud Roques
*
* Project Info: http://plantuml.sourceforge.net
*
* This file is part of PlantUML.
*
* PlantUML 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 3 of the License, or
* (at your option) any later version.
*
* PlantUML 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* Original Author: Arnaud Roques
*
* Revision $Revision: 9786 $
*
*/
package net.sourceforge.plantuml.code;
public class AsciiEncoder implements URLEncoder {
final private char encode6bit[] = new char[64];
final private byte decode6bit[] = new byte[128];
public AsciiEncoder() {
for (byte b = 0; b < 64; b++) {
encode6bit[b] = encode6bit(b);
decode6bit[encode6bit[b]] = b;
}
}
public String encode(byte data[]) {
final StringBuilder resu = new StringBuilder((data.length * 4 + 2) / 3);
for (int i = 0; i < data.length; i += 3) {
append3bytes(resu, data[i] & 0xFF, i + 1 < data.length ? data[i + 1] & 0xFF : 0,
i + 2 < data.length ? data[i + 2] & 0xFF : 0);
}
return resu.toString();
}
public byte[] decode(String s) {
if (s.length() % 4 != 0) {
throw new IllegalArgumentException("Cannot decode " + s);
}
final byte data[] = new byte[(s.length() * 3 + 3) / 4];
int pos = 0;
for (int i = 0; i < s.length(); i += 4) {
decode3bytes(data, pos, s.charAt(i), s.charAt(i + 1), s.charAt(i + 2), s.charAt(i + 3));
pos += 3;
}
return data;
}
public int decode6bit(char c) {
return decode6bit[c];
}
public char encode6bit(byte b) {
assert b >= 0 && b < 64;
if (b < 10) {
return (char) ('0' + b);
}
b -= 10;
if (b < 26) {
return (char) ('A' + b);
}
b -= 26;
if (b < 26) {
return (char) ('a' + b);
}
b -= 26;
if (b == 0) {
return '-';
}
if (b == 1) {
return '_';
}
assert false;
return '?';
}
private void append3bytes(StringBuilder sb, int b1, int b2, int b3) {
final int c1 = b1 >> 2;
final int c2 = ((b1 & 0x3) << 4) | (b2 >> 4);
final int c3 = ((b2 & 0xF) << 2) | (b3 >> 6);
final int c4 = b3 & 0x3F;
sb.append(encode6bit[c1 & 0x3F]);
sb.append(encode6bit[c2 & 0x3F]);
sb.append(encode6bit[c3 & 0x3F]);
sb.append(encode6bit[c4 & 0x3F]);
}
private void decode3bytes(byte r[], int pos, char cc1, char cc2, char cc3, char cc4) {
final int c1 = decode6bit[cc1];
final int c2 = decode6bit[cc2];
final int c3 = decode6bit[cc3];
final int c4 = decode6bit[cc4];
r[pos] = (byte) ((c1 << 2) | (c2 >> 4));
r[pos + 1] = (byte) (((c2 & 0x0F) << 4) | (c3 >> 2));
r[pos + 2] = (byte) (((c3 & 0x3) << 6) | c4);
}
}