org.springframework.web.method.annotation.MapMethodProcessor Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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
*
* https://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.web.method.annotation;
import java.util.Map;
import org.springframework.core.MethodParameter;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
import org.springframework.web.method.support.ModelAndViewContainer;
/**
* Resolves {@link Map} method arguments and handles {@link Map} return values.
*
* A Map return value can be interpreted in more than one ways depending
* on the presence of annotations like {@code @ModelAttribute} or
* {@code @ResponseBody}. Therefore this handler should be configured after
* the handlers that support these annotations.
*
* @author Rossen Stoyanchev
* @since 3.1
*/
public class MapMethodProcessor implements HandlerMethodArgumentResolver, HandlerMethodReturnValueHandler {
@Override
public boolean supportsParameter(MethodParameter parameter) {
return Map.class.isAssignableFrom(parameter.getParameterType());
}
@Override
public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
return mavContainer.getModel();
}
@Override
public boolean supportsReturnType(MethodParameter returnType) {
return Map.class.isAssignableFrom(returnType.getParameterType());
}
@Override
@SuppressWarnings({"unchecked", "rawtypes"})
public void handleReturnValue(Object returnValue, MethodParameter returnType,
ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception {
if (returnValue == null) {
return;
}
else if (returnValue instanceof Map){
mavContainer.addAllAttributes((Map) returnValue);
}
else {
// should not happen
throw new UnsupportedOperationException("Unexpected return type: " +
returnType.getParameterType().getName() + " in method: " + returnType.getMethod());
}
}
}