org.springframework.web.servlet.mvc.method.annotation.HttpHeadersReturnValueHandler Maven / Gradle / Ivy
/*
* Copyright 2002-2017 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.servlet.mvc.method.annotation;
import javax.servlet.http.HttpServletResponse;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpHeaders;
import org.springframework.http.server.ServletServerHttpResponse;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
import org.springframework.web.method.support.ModelAndViewContainer;
/**
* Handles {@link HttpHeaders} return values.
*
* @author Stephane Nicoll
* @since 4.0.1
*/
public class HttpHeadersReturnValueHandler implements HandlerMethodReturnValueHandler {
@Override
public boolean supportsReturnType(MethodParameter returnType) {
return HttpHeaders.class.isAssignableFrom(returnType.getParameterType());
}
@Override
@SuppressWarnings("resource")
public void handleReturnValue(@Nullable Object returnValue, MethodParameter returnType,
ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception {
mavContainer.setRequestHandled(true);
Assert.state(returnValue instanceof HttpHeaders, "HttpHeaders expected");
HttpHeaders headers = (HttpHeaders) returnValue;
if (!headers.isEmpty()) {
HttpServletResponse servletResponse = webRequest.getNativeResponse(HttpServletResponse.class);
Assert.state(servletResponse != null, "No HttpServletResponse");
ServletServerHttpResponse outputMessage = new ServletServerHttpResponse(servletResponse);
outputMessage.getHeaders().putAll(headers);
outputMessage.getBody(); // flush headers
}
}
}