/*
 * Copyright 2002-2017 the original author or 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 org.springframework.cache.support;

import java.io.Serializable;

import org.springframework.lang.Nullable;

Simple serializable class that serves as a null replacement for cache stores which otherwise do not support null values.
Author:Juergen Hoeller
See Also:
Since:4.2.2
/** * Simple serializable class that serves as a {@code null} replacement * for cache stores which otherwise do not support {@code null} values. * * @author Juergen Hoeller * @since 4.2.2 * @see AbstractValueAdaptingCache */
public final class NullValue implements Serializable {
The canonical representation of a null replacement, as used by the default implementation of AbstractValueAdaptingCache.toStoreValue/ AbstractValueAdaptingCache.fromStoreValue.
Since:4.3.10
/** * The canonical representation of a {@code null} replacement, as used by the * default implementation of {@link AbstractValueAdaptingCache#toStoreValue}/ * {@link AbstractValueAdaptingCache#fromStoreValue}. * @since 4.3.10 */
public static final Object INSTANCE = new NullValue(); private static final long serialVersionUID = 1L; private NullValue() { } private Object readResolve() { return INSTANCE; } @Override public boolean equals(@Nullable Object obj) { return (this == obj || obj == null); } @Override public int hashCode() { return NullValue.class.hashCode(); } @Override public String toString() { return "null"; } }