Here you can find the source of toString(Collection
static <T> String toString(Collection<T> list, String delimeter)
//package com.java2s; /*// ww w .j a va 2s.c om * The MIT License (MIT) * * Copyright (c) 2018 PikeTec GmbH * * 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. */ import java.util.Collection; public class Main { static <T> String toString(Collection<T> list, String delimeter) { StringBuilder sb = new StringBuilder(); for (T obj : list) { if (sb.length() > 0 && delimeter != null) { sb.append(delimeter); } sb.append(obj); } return sb.toString(); } }