1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.android.collect; 18 19 import java.util.ArrayList; 20 import java.util.Collections; 21 22 /** 23 * Provides static methods for creating {@code List} instances easily, and other 24 * utility methods for working with lists. 25 */ 26 public class Lists { 27 28 /** 29 * Creates an empty {@code ArrayList} instance. 30 * 31 * <p><b>Note:</b> if you only need an <i>immutable</i> empty List, use 32 * {@link Collections#emptyList} instead. 33 * 34 * @return a newly-created, initially-empty {@code ArrayList} 35 */ 36 public static <E> ArrayList<E> newArrayList() { 37 return new ArrayList<E>(); 38 } 39 40 /** 41 * Creates a resizable {@code ArrayList} instance containing the given 42 * elements. 43 * 44 * <p><b>Note:</b> due to a bug in javac 1.5.0_06, we cannot support the 45 * following: 46 * 47 * <p>{@code List<Base> list = Lists.newArrayList(sub1, sub2);} 48 * 49 * <p>where {@code sub1} and {@code sub2} are references to subtypes of 50 * {@code Base}, not of {@code Base} itself. To get around this, you must 51 * use: 52 * 53 * <p>{@code List<Base> list = Lists.<Base>newArrayList(sub1, sub2);} 54 * 55 * @param elements the elements that the list should contain, in order 56 * @return a newly-created {@code ArrayList} containing those elements 57 */ 58 public static <E> ArrayList<E> newArrayList(E... elements) { 59 int capacity = (elements.length * 110) / 100 + 5; 60 ArrayList<E> list = new ArrayList<E>(capacity); 61 Collections.addAll(list, elements); 62 return list; 63 } 64 } 65
