001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.bind.annotation;
018
019/**
020 * Common value constants shared between bind annotations.
021 *
022 * @author Juergen Hoeller
023 * @since 3.0.1
024 */
025public interface ValueConstants {
026
027        /**
028         * Constant defining a value for no default - as a replacement for
029         * {@code null} which we cannot use in annotation attributes.
030         * <p>This is an artificial arrangement of 16 unicode characters,
031         * with its sole purpose being to never match user-declared values.
032         * @see RequestParam#defaultValue()
033         * @see RequestHeader#defaultValue()
034         * @see CookieValue#defaultValue()
035         */
036        String DEFAULT_NONE = "\n\t\t\n\t\t\n\uE000\uE001\uE002\n\t\t\t\t\n";
037
038}