Here you can find the source of lastIndexOf(StringBuffer buf, String str)
public static int lastIndexOf(StringBuffer buf, String str)
//package com.java2s; /*//from w w w .j a v a 2 s .c o m StringUtils.java : A stand alone utility class. Copyright (C) 2000 Justin P. McCarthy 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 2.1 of the License, or (at your option) any later version. This library 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 Lesser General Public License along with this library; if not, see <http://www.gnu.org/licenses/>. To further contact the author please email jpmccar@gjt.org Modifications, copyright 2001-2014 Tuma Solutions, LLC; distributed under the LGPL, as described above. */ public class Main { /** Performs the equivalent of buf.toString().lastIndexOf(str), but is * much more memory efficient. */ public static int lastIndexOf(StringBuffer buf, String str) { return lastIndexOf(buf, str, buf.length()); } /** Performs the equivalent of buf.toString().lastIndexOf(str, fromIndex), * but is much more memory efficient. */ public static int lastIndexOf(StringBuffer buf, String str, int fromIndex) { // This method didn't exist in Java 1.3, but does now. return buf.lastIndexOf(str, fromIndex); } }