| /* |
| * 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.util; |
| |
| import java.util.Arrays; |
| |
| /** |
| * Helper functions that can operate on any {@code Object}. |
| * |
| * @author Laurence Gonsalves |
| */ |
| public final class Objects { |
| private Objects() {} |
| |
| /** |
| * Determines whether two possibly-null objects are equal. Returns: |
| * |
| * <ul> |
| * <li>{@code true} if {@code a} and {@code b} are both null. |
| * <li>{@code true} if {@code a} and {@code b} are both non-null and they are |
| * equal according to {@link Object#equals(Object)}. |
| * <li>{@code false} in all other situations. |
| * </ul> |
| * |
| * <p>This assumes that any non-null objects passed to this function conform |
| * to the {@code equals()} contract. |
| */ |
| public static boolean equal(@Nullable Object a, @Nullable Object b) { |
| return a == b || (a != null && a.equals(b)); |
| } |
| |
| /** |
| * Generates a hash code for multiple values. The hash code is generated by |
| * calling {@link Arrays#hashCode(Object[])}. |
| * |
| * <p>This is useful for implementing {@link Object#hashCode()}. For example, |
| * in an object that has three properties, {@code x}, {@code y}, and |
| * {@code z}, one could write: |
| * <pre> |
| * public int hashCode() { |
| * return Objects.hashCode(getX(), getY(), getZ()); |
| * }</pre> |
| * |
| * <b>Warning</b>: When a single object is supplied, the returned hash code |
| * does not equal the hash code of that object. |
| */ |
| public static int hashCode(Object... objects) { |
| return Arrays.hashCode(objects); |
| } |
| } |