Here you can find the source of join(String separator, List
public static String join(String separator, List<String> parts)
//package com.java2s; /*/*from w w w.j a v a2s .c o m*/ * Copyright Red Hat Inc. and/or its affiliates and other contributors * as indicated by the authors tag. All rights reserved. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions * of the GNU General Public License version 2. * * This particular file is subject to the "Classpath" exception as provided in the * LICENSE file that accompanied this code. * * This program is distributed in the hope that it will be useful, but WITHOUT A * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A * PARTICULAR PURPOSE. See the GNU General Public License for more details. * You should have received a copy of the GNU General Public License, * along with this distribution; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301, USA. */ import java.util.Iterator; import java.util.List; public class Main { public static String join(String separator, List<String> parts) { StringBuilder stringBuilder = new StringBuilder(); Iterator<String> iterator = parts.iterator(); while (iterator.hasNext()) { stringBuilder.append(iterator.next()); if (iterator.hasNext()) stringBuilder.append(separator); } return stringBuilder.toString(); } }