org.springframework.boot.autoconfigure.web.servlet.error.DefaultErrorViewResolver 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.error;
import java.util.Collections;
import java.util.EnumMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.boot.autoconfigure.template.TemplateAvailabilityProvider;
import org.springframework.boot.autoconfigure.template.TemplateAvailabilityProviders;
import org.springframework.boot.autoconfigure.web.ResourceProperties;
import org.springframework.context.ApplicationContext;
import org.springframework.core.Ordered;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpStatus;
import org.springframework.http.HttpStatus.Series;
import org.springframework.http.MediaType;
import org.springframework.util.Assert;
import org.springframework.util.FileCopyUtils;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.View;
/**
* Default {@link ErrorViewResolver} implementation that attempts to resolve error views
* using well known conventions. Will search for templates and static assets under
* {@code '/error'} using the {@link HttpStatus status code} and the
* {@link HttpStatus#series() status series}.
*
* For example, an {@code HTTP 404} will search (in the specific order):
*
* - {@code '/
/error/404.'}
* - {@code '/
/error/404.html'}
* - {@code '/
/error/4xx.'}
* - {@code '/
/error/4xx.html'}
*
*
* @author Phillip Webb
* @author Andy Wilkinson
* @since 1.4.0
*/
public class DefaultErrorViewResolver implements ErrorViewResolver, Ordered {
private static final Map SERIES_VIEWS;
static {
Map views = new EnumMap<>(Series.class);
views.put(Series.CLIENT_ERROR, "4xx");
views.put(Series.SERVER_ERROR, "5xx");
SERIES_VIEWS = Collections.unmodifiableMap(views);
}
private ApplicationContext applicationContext;
private final ResourceProperties resourceProperties;
private final TemplateAvailabilityProviders templateAvailabilityProviders;
private int order = Ordered.LOWEST_PRECEDENCE;
/**
* Create a new {@link DefaultErrorViewResolver} instance.
* @param applicationContext the source application context
* @param resourceProperties resource properties
*/
public DefaultErrorViewResolver(ApplicationContext applicationContext, ResourceProperties resourceProperties) {
Assert.notNull(applicationContext, "ApplicationContext must not be null");
Assert.notNull(resourceProperties, "ResourceProperties must not be null");
this.applicationContext = applicationContext;
this.resourceProperties = resourceProperties;
this.templateAvailabilityProviders = new TemplateAvailabilityProviders(applicationContext);
}
DefaultErrorViewResolver(ApplicationContext applicationContext, ResourceProperties resourceProperties,
TemplateAvailabilityProviders templateAvailabilityProviders) {
Assert.notNull(applicationContext, "ApplicationContext must not be null");
Assert.notNull(resourceProperties, "ResourceProperties must not be null");
this.applicationContext = applicationContext;
this.resourceProperties = resourceProperties;
this.templateAvailabilityProviders = templateAvailabilityProviders;
}
@Override
public ModelAndView resolveErrorView(HttpServletRequest request, HttpStatus status, Map model) {
ModelAndView modelAndView = resolve(String.valueOf(status.value()), model);
if (modelAndView == null && SERIES_VIEWS.containsKey(status.series())) {
modelAndView = resolve(SERIES_VIEWS.get(status.series()), model);
}
return modelAndView;
}
private ModelAndView resolve(String viewName, Map model) {
String errorViewName = "error/" + viewName;
TemplateAvailabilityProvider provider = this.templateAvailabilityProviders.getProvider(errorViewName,
this.applicationContext);
if (provider != null) {
return new ModelAndView(errorViewName, model);
}
return resolveResource(errorViewName, model);
}
private ModelAndView resolveResource(String viewName, Map model) {
for (String location : this.resourceProperties.getStaticLocations()) {
try {
Resource resource = this.applicationContext.getResource(location);
resource = resource.createRelative(viewName + ".html");
if (resource.exists()) {
return new ModelAndView(new HtmlResourceView(resource), model);
}
}
catch (Exception ex) {
}
}
return null;
}
@Override
public int getOrder() {
return this.order;
}
public void setOrder(int order) {
this.order = order;
}
/**
* {@link View} backed by an HTML resource.
*/
private static class HtmlResourceView implements View {
private Resource resource;
HtmlResourceView(Resource resource) {
this.resource = resource;
}
@Override
public String getContentType() {
return MediaType.TEXT_HTML_VALUE;
}
@Override
public void render(Map model, HttpServletRequest request, HttpServletResponse response)
throws Exception {
response.setContentType(getContentType());
FileCopyUtils.copy(this.resource.getInputStream(), response.getOutputStream());
}
}
}