| /* |
| * Copyright (C) 2007 Google Inc. |
| * |
| * 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. |
| */ |
| |
| package com.google.inject.internal; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| /** |
| * Static utility methods pertaining to {@link List} instances. Also see this |
| * class's counterparts {@link Sets} and {@link Maps}. |
| * |
| * @author Kevin Bourrillion |
| * @author Mike Bostock |
| */ |
| public final class Lists { |
| private Lists() {} |
| |
| // ArrayList |
| |
| /** |
| * Creates an empty {@code ArrayList} instance. |
| * |
| * <p><b>Note:</b> if you need an immutable empty list, use {@link |
| * Collections#emptyList} instead. |
| * |
| * @return a new, empty {@code ArrayList} |
| */ |
| public static <E> ArrayList<E> newArrayList() { |
| return new ArrayList<E>(); |
| } |
| |
| /** |
| * Creates an {@code ArrayList} instance containing the given elements. |
| * |
| * <p><b>Note:</b> if you need an immutable List, use {@link ImmutableList} |
| * instead. |
| * |
| * <p><b>Note:</b> due to a bug in javac 1.5.0_06, we cannot support the |
| * following: |
| * |
| * <p>{@code List<Base> list = Lists.newArrayList(sub1, sub2);} |
| * |
| * <p>where {@code sub1} and {@code sub2} are references to subtypes of {@code |
| * Base}, not of {@code Base} itself. To get around this, you must use: |
| * |
| * <p>{@code List<Base> list = Lists.<Base>newArrayList(sub1, sub2);} |
| * |
| * @param elements the elements that the list should contain, in order |
| * @return a new {@code ArrayList} containing those elements |
| */ |
| public static <E> ArrayList<E> newArrayList(E... elements) { |
| // Avoid integer overflow when a large array is passed in |
| int capacity = computeArrayListCapacity(elements.length); |
| ArrayList<E> list = new ArrayList<E>(capacity); |
| Collections.addAll(list, elements); |
| return list; |
| } |
| |
| static int computeArrayListCapacity(int arraySize) { |
| Preconditions.checkArgument(arraySize >= 0); |
| |
| // TODO: Figure out the right behavior, and document it |
| return (int) Math.min(5L + arraySize + (arraySize / 10), Integer.MAX_VALUE); |
| } |
| |
| /** |
| * Creates an {@code ArrayList} instance containing the given elements. |
| * |
| * @param elements the elements that the list should contain, in order |
| * @return a new {@code ArrayList} containing those elements |
| */ |
| public static <E> ArrayList<E> newArrayList(Iterable<? extends E> elements) { |
| // Let ArrayList's sizing logic work, if possible |
| if (elements instanceof Collection) { |
| @SuppressWarnings("unchecked") |
| Collection<? extends E> collection = (Collection<? extends E>) elements; |
| return new ArrayList<E>(collection); |
| } else { |
| return newArrayList(elements.iterator()); |
| } |
| } |
| |
| /** |
| * Creates an {@code ArrayList} instance containing the given elements. |
| * |
| * @param elements the elements that the list should contain, in order |
| * @return a new {@code ArrayList} containing those elements |
| */ |
| public static <E> ArrayList<E> newArrayList(Iterator<? extends E> elements) { |
| ArrayList<E> list = newArrayList(); |
| while (elements.hasNext()) { |
| list.add(elements.next()); |
| } |
| return list; |
| } |
| |
| |
| /** |
| * Returns an unmodifiable list containing the specified first element and |
| * the additional elements. |
| */ |
| public static <E> ArrayList<E> newArrayList(@Nullable E first, E[] rest) { |
| ArrayList<E> result = new ArrayList<E>(rest.length + 1); |
| result.add(first); |
| for (E element : rest) { |
| result.add(element); |
| } |
| return result; |
| } |
| } |