com.google.inject.internal.Objects Maven / Gradle / Ivy
/*
* 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.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:
*
*
* - {@code true} if {@code a} and {@code b} are both null.
*
- {@code true} if {@code a} and {@code b} are both non-null and they are
* equal according to {@link Object#equals(Object)}.
*
- {@code false} in all other situations.
*
*
* 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[])}.
*
*
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:
*
* public int hashCode() {
* return Objects.hashCode(getX(), getY(), getZ());
* }
*
* Warning: 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);
}
}