001/*
002 * Copyright 2002-2017 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.reactive.result.method.annotation;
018
019import reactor.core.publisher.Mono;
020
021import org.springframework.beans.factory.config.ConfigurableBeanFactory;
022import org.springframework.core.MethodParameter;
023import org.springframework.core.ReactiveAdapterRegistry;
024import org.springframework.util.Assert;
025import org.springframework.web.bind.annotation.SessionAttribute;
026import org.springframework.web.bind.annotation.ValueConstants;
027import org.springframework.web.server.ServerWebExchange;
028import org.springframework.web.server.ServerWebInputException;
029
030/**
031 * Resolves method arguments annotated with an @{@link SessionAttribute}.
032 *
033 * @author Rossen Stoyanchev
034 * @since 5.0
035 * @see RequestAttributeMethodArgumentResolver
036 */
037public class SessionAttributeMethodArgumentResolver extends AbstractNamedValueArgumentResolver {
038
039        public SessionAttributeMethodArgumentResolver(ConfigurableBeanFactory factory, ReactiveAdapterRegistry registry) {
040                super(factory, registry);
041        }
042
043
044        @Override
045        public boolean supportsParameter(MethodParameter parameter) {
046                return parameter.hasParameterAnnotation(SessionAttribute.class);
047        }
048
049        @Override
050        protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
051                SessionAttribute ann = parameter.getParameterAnnotation(SessionAttribute.class);
052                Assert.state(ann != null, "No SessionAttribute annotation");
053                return new NamedValueInfo(ann.name(), ann.required(), ValueConstants.DEFAULT_NONE);
054        }
055
056        @Override
057        protected Mono<Object> resolveName(String name, MethodParameter parameter, ServerWebExchange exchange) {
058                return exchange.getSession()
059                                .filter(session -> session.getAttribute(name) != null)
060                                .map(session -> session.getAttribute(name));
061        }
062
063        @Override
064        protected void handleMissingValue(String name, MethodParameter parameter) {
065                String type = parameter.getNestedParameterType().getSimpleName();
066                String reason = "Missing session attribute '" + name + "' of type " + type;
067                throw new ServerWebInputException(reason, parameter);
068        }
069
070}