Here you can find the source of replace(final String regex, final String replacement, final StringBuffer source, boolean all)
public void replace(final String regex, final String replacement, final StringBuffer source, boolean all)
//package com.java2s; /*//from www . j av a2s . c o m This library is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details. You should have received a copy of the GNU General Public License along with this library. If not, see <http://www.gnu.org/licenses/>. */ import java.util.regex.Matcher; import java.util.regex.Pattern; public class Main { /** * Replaces all occurrences of <code>oldChar</code> in this string with * <code>newChar</code>. * * @param src * source {@link StringBuilder} to be modified * @param oldChar * the old character. * @param newChar * newChar the new character * @see String#replace(char, char) */ public static void replace(final StringBuilder src, char oldChar, char newChar) { for (int i = 0; i < src.length(); i++) { if (src.charAt(i) == oldChar) { src.setCharAt(i, newChar); } } } public void replace(final String regex, final String replacement, final StringBuffer source, boolean all) { Pattern pattern = Pattern.compile(regex); final Matcher matcher = pattern.matcher(source); if (all) { matcher.replaceAll(replacement); } else { matcher.replaceFirst(replacement); } } }