/*
* Copyright 2002-2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.messaging.handler.annotation.support;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;
import org.springframework.core.MethodParameter;
import org.springframework.core.convert.ConversionService;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHandlingException;
import org.springframework.messaging.handler.annotation.Header;
import org.springframework.messaging.support.NativeMessageHeaderAccessor;
/**
* Resolves method parameters annotated with {@link Header @Header}.
*
* @author Rossen Stoyanchev
* @since 4.0
*/
public class HeaderMethodArgumentResolver extends AbstractNamedValueMethodArgumentResolver {
private static final Log logger = LogFactory.getLog(HeaderMethodArgumentResolver.class);
public HeaderMethodArgumentResolver(ConversionService cs, ConfigurableBeanFactory beanFactory) {
super(cs, beanFactory);
}
@Override
public boolean supportsParameter(MethodParameter parameter) {
return parameter.hasParameterAnnotation(Header.class);
}
@Override
protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
Header annotation = parameter.getParameterAnnotation(Header.class);
return new HeaderNamedValueInfo(annotation);
}
@Override
protected Object resolveArgumentInternal(MethodParameter parameter, Message<?> message, String name)
throws Exception {
Object headerValue = message.getHeaders().get(name);
Object nativeHeaderValue = getNativeHeaderValue(message, name);
if (headerValue != null && nativeHeaderValue != null) {
if (logger.isWarnEnabled()) {
logger.warn("Message headers contain two values for the same header '" + name + "', " +
"one in the top level header map and a second in the nested map with native headers. " +
"Using the value from top level map. " +
"Use 'nativeHeader.myHeader' to resolve to the value from the nested native header map." );
}
}
return (headerValue != null ? headerValue : nativeHeaderValue);
}
private Object getNativeHeaderValue(Message<?> message, String name) {
Map<String, List<String>> nativeHeaders = getNativeHeaders(message);
if (name.startsWith("nativeHeaders.")) {
name = name.substring("nativeHeaders.".length());
}
if (nativeHeaders == null || !nativeHeaders.containsKey(name)) {
return null;
}
List<?> nativeHeaderValues = nativeHeaders.get(name);
return (nativeHeaderValues.size() == 1 ? nativeHeaderValues.get(0) : nativeHeaderValues);
}
@SuppressWarnings("unchecked")
private Map<String, List<String>> getNativeHeaders(Message<?> message) {
return (Map<String, List<String>>) message.getHeaders().get(
NativeMessageHeaderAccessor.NATIVE_HEADERS);
}
@Override
protected void handleMissingValue(String headerName, MethodParameter parameter, Message<?> message) {
throw new MessageHandlingException(message, "Missing header '" + headerName +
"' for method parameter type [" + parameter.getParameterType() + "]");
}
private static class HeaderNamedValueInfo extends NamedValueInfo {
private HeaderNamedValueInfo(Header annotation) {
super(annotation.value(), annotation.required(), annotation.defaultValue());
}
}
}