001/*
002 * Copyright 2002-2016 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.context.request;
018
019import org.springframework.lang.Nullable;
020
021/**
022 * Request-backed {@link org.springframework.beans.factory.config.Scope}
023 * implementation.
024 *
025 * <p>Relies on a thread-bound {@link RequestAttributes} instance, which
026 * can be exported through {@link RequestContextListener},
027 * {@link org.springframework.web.filter.RequestContextFilter} or
028 * {@link org.springframework.web.servlet.DispatcherServlet}.
029 *
030 * @author Rod Johnson
031 * @author Juergen Hoeller
032 * @author Rob Harrop
033 * @since 2.0
034 * @see RequestContextHolder#currentRequestAttributes()
035 * @see RequestAttributes#SCOPE_REQUEST
036 * @see RequestContextListener
037 * @see org.springframework.web.filter.RequestContextFilter
038 * @see org.springframework.web.servlet.DispatcherServlet
039 */
040public class RequestScope extends AbstractRequestAttributesScope {
041
042        @Override
043        protected int getScope() {
044                return RequestAttributes.SCOPE_REQUEST;
045        }
046
047        /**
048         * There is no conversation id concept for a request, so this method
049         * returns {@code null}.
050         */
051        @Override
052        @Nullable
053        public String getConversationId() {
054                return null;
055        }
056
057}