org.springframework.boot.autoconfigure.web.servlet.WelcomePageHandlerMapping Maven / Gradle / Ivy
/*
* Copyright 2012-2019 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.boot.autoconfigure.web.servlet;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.boot.autoconfigure.template.TemplateAvailabilityProviders;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.handler.AbstractUrlHandlerMapping;
import org.springframework.web.servlet.mvc.ParameterizableViewController;
/**
* An {@link AbstractUrlHandlerMapping} for an application's welcome page. Supports both
* static and templated files. If both a static and templated index page are available,
* the static page is preferred.
*
* @author Andy Wilkinson
* @author Bruce Brouwer
*/
final class WelcomePageHandlerMapping extends AbstractUrlHandlerMapping {
private static final Log logger = LogFactory.getLog(WelcomePageHandlerMapping.class);
private static final List MEDIA_TYPES_ALL = Collections.singletonList(MediaType.ALL);
WelcomePageHandlerMapping(TemplateAvailabilityProviders templateAvailabilityProviders,
ApplicationContext applicationContext, Optional welcomePage, String staticPathPattern) {
if (welcomePage.isPresent() && "/**".equals(staticPathPattern)) {
logger.info("Adding welcome page: " + welcomePage.get());
setRootViewName("forward:index.html");
}
else if (welcomeTemplateExists(templateAvailabilityProviders, applicationContext)) {
logger.info("Adding welcome page template: index");
setRootViewName("index");
}
}
private boolean welcomeTemplateExists(TemplateAvailabilityProviders templateAvailabilityProviders,
ApplicationContext applicationContext) {
return templateAvailabilityProviders.getProvider("index", applicationContext) != null;
}
private void setRootViewName(String viewName) {
ParameterizableViewController controller = new ParameterizableViewController();
controller.setViewName(viewName);
setRootHandler(controller);
setOrder(2);
}
@Override
public Object getHandlerInternal(HttpServletRequest request) throws Exception {
for (MediaType mediaType : getAcceptedMediaTypes(request)) {
if (mediaType.includes(MediaType.TEXT_HTML)) {
return super.getHandlerInternal(request);
}
}
return null;
}
private List getAcceptedMediaTypes(HttpServletRequest request) {
String acceptHeader = request.getHeader(HttpHeaders.ACCEPT);
if (StringUtils.hasText(acceptHeader)) {
return MediaType.parseMediaTypes(acceptHeader);
}
return MEDIA_TYPES_ALL;
}
}