001/*
002 * Copyright 2002-2019 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.servlet.mvc.method.annotation;
018
019import javax.servlet.ServletException;
020
021import org.springframework.core.MethodParameter;
022import org.springframework.web.bind.ServletRequestBindingException;
023import org.springframework.web.bind.annotation.SessionAttribute;
024import org.springframework.web.bind.annotation.ValueConstants;
025import org.springframework.web.context.request.NativeWebRequest;
026import org.springframework.web.context.request.RequestAttributes;
027import org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver;
028
029/**
030 * Resolves method arguments annotated with an @{@link SessionAttribute}.
031 *
032 * @author Rossen Stoyanchev
033 * @since 4.3
034 */
035public class SessionAttributeMethodArgumentResolver extends AbstractNamedValueMethodArgumentResolver {
036
037        @Override
038        public boolean supportsParameter(MethodParameter parameter) {
039                return parameter.hasParameterAnnotation(SessionAttribute.class);
040        }
041
042        @Override
043        protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
044                SessionAttribute ann = parameter.getParameterAnnotation(SessionAttribute.class);
045                return new NamedValueInfo(ann.name(), ann.required(), ValueConstants.DEFAULT_NONE);
046        }
047
048        @Override
049        protected Object resolveName(String name, MethodParameter parameter, NativeWebRequest request){
050                return request.getAttribute(name, RequestAttributes.SCOPE_SESSION);
051        }
052
053        @Override
054        protected void handleMissingValue(String name, MethodParameter parameter) throws ServletException {
055                throw new ServletRequestBindingException("Missing session attribute '" + name +
056                                "' of type " + parameter.getNestedParameterType().getSimpleName());
057        }
058
059}