001/* 002 * Copyright 2002-2015 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.method.annotation; 018 019import java.util.Map; 020 021import org.springframework.beans.factory.config.ConfigurableBeanFactory; 022import org.springframework.core.MethodParameter; 023import org.springframework.web.bind.ServletRequestBindingException; 024import org.springframework.web.bind.WebDataBinder; 025import org.springframework.web.bind.annotation.RequestHeader; 026import org.springframework.web.context.request.NativeWebRequest; 027 028/** 029 * Resolves method arguments annotated with {@code @RequestHeader} except for 030 * {@link Map} arguments. See {@link RequestHeaderMapMethodArgumentResolver} for 031 * details on {@link Map} arguments annotated with {@code @RequestHeader}. 032 * 033 * <p>An {@code @RequestHeader} is a named value resolved from a request header. 034 * It has a required flag and a default value to fall back on when the request 035 * header does not exist. 036 * 037 * <p>A {@link WebDataBinder} is invoked to apply type conversion to resolved 038 * request header values that don't yet match the method parameter type. 039 * 040 * @author Arjen Poutsma 041 * @author Rossen Stoyanchev 042 * @since 3.1 043 */ 044public class RequestHeaderMethodArgumentResolver extends AbstractNamedValueMethodArgumentResolver { 045 046 /** 047 * @param beanFactory a bean factory to use for resolving ${...} 048 * placeholder and #{...} SpEL expressions in default values; 049 * or {@code null} if default values are not expected to have expressions 050 */ 051 public RequestHeaderMethodArgumentResolver(ConfigurableBeanFactory beanFactory) { 052 super(beanFactory); 053 } 054 055 056 @Override 057 public boolean supportsParameter(MethodParameter parameter) { 058 return (parameter.hasParameterAnnotation(RequestHeader.class) && 059 !Map.class.isAssignableFrom(parameter.nestedIfOptional().getNestedParameterType())); 060 } 061 062 @Override 063 protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) { 064 RequestHeader annotation = parameter.getParameterAnnotation(RequestHeader.class); 065 return new RequestHeaderNamedValueInfo(annotation); 066 } 067 068 @Override 069 protected Object resolveName(String name, MethodParameter parameter, NativeWebRequest request) throws Exception { 070 String[] headerValues = request.getHeaderValues(name); 071 if (headerValues != null) { 072 return (headerValues.length == 1 ? headerValues[0] : headerValues); 073 } 074 else { 075 return null; 076 } 077 } 078 079 @Override 080 protected void handleMissingValue(String name, MethodParameter parameter) throws ServletRequestBindingException { 081 throw new ServletRequestBindingException("Missing request header '" + name + 082 "' for method parameter of type " + parameter.getNestedParameterType().getSimpleName()); 083 } 084 085 086 private static class RequestHeaderNamedValueInfo extends NamedValueInfo { 087 088 private RequestHeaderNamedValueInfo(RequestHeader annotation) { 089 super(annotation.name(), annotation.required(), annotation.defaultValue()); 090 } 091 } 092 093}