Here you can find the source of copyList(Collection
public static <T> List<T> copyList(Collection<T> list)
//package com.java2s; /*//w w w . jav a2 s.com * Copyright 2004-2016 EPAM Systems * * This file is part of JDI project. * * JDI 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. * * JDI 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 JDI. If not, see <http://www.gnu.org/licenses/>. */ import java.util.*; public class Main { public static <T> List<T> copyList(Collection<T> list) { List<T> result = new ArrayList<>(); for (T el : list) result.add(el); return result; } }