Here you can find the source of length(String buffer)
public static int length(String buffer)
//package com.java2s; /**//from ww w .j a va 2s . c o m * $RCSfile: StringUtils.java,v $ * $Revision: 1.1.1.1 $ * $Date: 2007/03/01 00:17:45 $ * * Copyright (C) 2000 CoolServlets.com. All rights reserved. * * =================================================================== * The Apache Software License, Version 1.1 * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by * CoolServlets.com (http://www.Yasna.com)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Jive" and "CoolServlets.com" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please * contact webmaster@Yasna.com. * * 5. Products derived from this software may not be called "Jive", * nor may "Jive" appear in their name, without prior written * permission of CoolServlets.com. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL COOLSERVLETS.COM OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of CoolServlets.com. For more information * on CoolServlets.com, please see <http://www.Yasna.com>. */ public class Main { public static int length(String buffer) { if (buffer == null || buffer.equals("")) { return 0; } return buffer.getBytes().length; } }