src/main/java/org/snt/autorex/utils/EscapeUtils.java
/**
* autorex - fsm state eliminator
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Julian Thome <julian.thome.de@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to do
* so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
**/
package org.snt.autorex.utils;
import java.util.Set;
import java.util.stream.Stream;
import static java.util.stream.Collectors.toSet;
/**
* escaping helper class
*/
public final class EscapeUtils {
private static final Set<Character> SPECIAL = Stream.of('+', '{', '}', '(', ')', '[', ']', '&', '^',
'-', '?', '*', '\"', '$', '<', '>', '.', '|', '#').collect(toSet());
private EscapeUtils() {
}
/**
* escape special character in a string with a backslash
*
* @param s string to be escaped
* @return escaped string
*/
public static String escapeSpecialCharacters(String s) {
if (s == null)
return "";
StringBuilder out = new StringBuilder();
for (char c : s.toCharArray()) {
if (SPECIAL.contains(c)) {
out.append("\\").append(c);
} else {
out.append(c);
}
}
return out.toString();
}
/**
* unescape special character in a string
*
* @param s string to be unescaped
* @return unescaped string
*/
public static String unescapeSpecialCharacters(String s) {
if (s == null)
return "";
StringBuilder out = new StringBuilder();
char pred = ' ';
for (char c : s.toCharArray()) {
if (pred == '\\' && SPECIAL.contains(c)) {
out.deleteCharAt(out.length() - 1);
out.append(c);
} else {
out.append(c);
}
pred = c;
}
return out.toString();
}
}