org.springframework.web.servlet.function.support.HandlerFunctionAdapter Maven / Gradle / Ivy
/*
* Copyright 2002-2019 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.function.support;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.core.Ordered;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.servlet.HandlerAdapter;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.function.HandlerFunction;
import org.springframework.web.servlet.function.RouterFunctions;
import org.springframework.web.servlet.function.ServerRequest;
import org.springframework.web.servlet.function.ServerResponse;
/**
* {@code HandlerAdapter} implementation that supports {@link HandlerFunction}s.
*
* @author Arjen Poutsma
* @since 5.2
*/
public class HandlerFunctionAdapter implements HandlerAdapter, Ordered {
private int order = Ordered.LOWEST_PRECEDENCE;
/**
* Specify the order value for this HandlerAdapter bean.
* The default value is {@code Ordered.LOWEST_PRECEDENCE}, meaning non-ordered.
* @see org.springframework.core.Ordered#getOrder()
*/
public void setOrder(int order) {
this.order = order;
}
@Override
public int getOrder() {
return this.order;
}
@Override
public boolean supports(Object handler) {
return handler instanceof HandlerFunction;
}
@Nullable
@Override
public ModelAndView handle(HttpServletRequest servletRequest,
HttpServletResponse servletResponse,
Object handler) throws Exception {
HandlerFunction handlerFunction = (HandlerFunction) handler;
ServerRequest serverRequest = getServerRequest(servletRequest);
ServerResponse serverResponse = handlerFunction.handle(serverRequest);
return serverResponse.writeTo(servletRequest, servletResponse,
new ServerRequestContext(serverRequest));
}
private ServerRequest getServerRequest(HttpServletRequest servletRequest) {
ServerRequest serverRequest =
(ServerRequest) servletRequest.getAttribute(RouterFunctions.REQUEST_ATTRIBUTE);
Assert.state(serverRequest != null, () -> "Required attribute '" +
RouterFunctions.REQUEST_ATTRIBUTE + "' is missing");
return serverRequest;
}
@Override
public long getLastModified(HttpServletRequest request, Object handler) {
return -1L;
}
private static class ServerRequestContext implements ServerResponse.Context {
private final ServerRequest serverRequest;
public ServerRequestContext(ServerRequest serverRequest) {
this.serverRequest = serverRequest;
}
@Override
public List> messageConverters() {
return this.serverRequest.messageConverters();
}
}
}