Files
ma1sd/src/main/java/io/kamax/matrix/MatrixIdCodec.java

94 lines
3.0 KiB
Java

/*
* matrix-java-sdk - Matrix Client SDK for Java
* Copyright (C) 2018 Kamax Sarl
*
* https://www.kamax.io/
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package io.kamax.matrix;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;
import java.nio.charset.StandardCharsets;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import static io.kamax.matrix.MatrixID.ALLOWED_CHARS;
public class MatrixIdCodec {
public static final String DELIMITER = "=";
public static final String ENCODE_REGEX = "[^" + ALLOWED_CHARS + "]+";
public static final Pattern ENCODE_PATTERN = Pattern.compile(ENCODE_REGEX);
public static final Pattern DECODE_PATTERN = Pattern.compile("(=[0-9a-f]{2})+");
private MatrixIdCodec() {
// not for public consumption
}
public static String encode(String decoded) {
decoded = decoded.toLowerCase();
StringBuilder builder = new StringBuilder();
for (Character c : decoded.toCharArray()) {
String s = c.toString();
Matcher lp = ENCODE_PATTERN.matcher(s);
if (!lp.find()) {
builder.append(s);
} else {
for (byte b : c.toString().getBytes(StandardCharsets.UTF_8)) {
builder.append(DELIMITER);
builder.append(Hex.encodeHexString(new byte[] { b }));
}
}
}
return builder.toString();
}
public static String decode(String encoded) {
StringBuilder builder = new StringBuilder();
Matcher m = DECODE_PATTERN.matcher(encoded);
int prevEnd = 0;
while (m.find()) {
try {
int start = m.start();
int end = m.end();
String sub = encoded.substring(start, end).replaceAll(DELIMITER, "");
String decoded = new String(Hex.decodeHex(sub.toCharArray()), StandardCharsets.UTF_8);
builder.append(encoded, prevEnd, start);
builder.append(decoded);
prevEnd = end - 1;
} catch (DecoderException e) {
e.printStackTrace();
}
}
prevEnd++;
if (prevEnd < encoded.length()) {
builder.append(encoded, prevEnd, encoded.length());
}
if (builder.length() == 0) {
return encoded;
} else {
return builder.toString();
}
}
}