Here you can find the source of toList(Iterable
public static <T> List<T> toList(Iterable<T> iterable)
//package com.java2s; /*/*w ww .ja v a 2 s .com*/ * Copyright 2016 Jakub Jirutka <jakub@jirutka.cz>. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.ArrayList; import java.util.List; public class Main { /** * Converts the given Iterable into an ArrayList. */ public static <T> List<T> toList(Iterable<T> iterable) { if (iterable instanceof List) { return (List<T>) iterable; } List<T> result = new ArrayList<>(); for (T item : iterable) { result.add(item); } return result; } }