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/*
 * Copyright (C) 2007 The Guava Authors
 *
 * 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.common.base;

import com.google.common.annotations.GwtCompatible;
import java.util.Arrays;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Helper functions that can operate on any {@code Object}.
 *
 * 

See the Guava User Guide on writing {@code Object} * methods with {@code Objects}. * * @author Laurence Gonsalves * @since 2.0 */ @GwtCompatible public final class Objects extends ExtraObjectsMethodsForWeb { 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. * *

Note for Java 7 and later: This method should be treated as deprecated; use {@link * java.util.Objects#equals} instead. */ 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[])}. Note that array arguments to this method, with the exception of a * single Object array, do not get any special handling; their hash codes are based on identity * and not contents. * *

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: * *

{@code
   * 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. * *

Note for Java 7 and later: This method should be treated as deprecated; use {@link * java.util.Objects#hash} instead. */ public static int hashCode(@Nullable Object @Nullable ... objects) { return Arrays.hashCode(objects); } }





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