/*
* 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
*
* http://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.reactive.config;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.springframework.beans.factory.BeanInitializationException;
import org.springframework.context.ApplicationContext;
import org.springframework.util.Assert;
import org.springframework.web.reactive.accept.CompositeContentTypeResolver;
import org.springframework.web.reactive.handler.AbstractHandlerMapping;
import org.springframework.web.reactive.handler.SimpleUrlHandlerMapping;
import org.springframework.web.reactive.resource.ResourceWebHandler;
import org.springframework.web.server.WebHandler;
/**
* Stores registrations of resource handlers for serving static resources such
* as images, css files and others through Spring WebFlux including setting cache
* headers optimized for efficient loading in a web browser. Resources can be
* served out of locations under web application root, from the classpath, and
* others.
*
* <p>To create a resource handler, use {@link #addResourceHandler(String...)}
* providing the URL path patterns for which the handler should be invoked to
* serve static resources (e.g. {@code "/resources/**"}).
*
* <p>Then use additional methods on the returned
* {@link ResourceHandlerRegistration} to add one or more locations from which
* to serve static content from (e.g. {{@code "/"},
* {@code "classpath:/META-INF/public-web-resources/"}}) or to specify a cache
* period for served resources.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
public class ResourceHandlerRegistry {
private final ApplicationContext applicationContext;
private final CompositeContentTypeResolver contentTypeResolver;
private final List<ResourceHandlerRegistration> registrations = new ArrayList<>();
private int order = Integer.MAX_VALUE -1;
/**
* Create a new resource handler registry for the given application context.
* @param applicationContext the Spring application context
*/
public ResourceHandlerRegistry(ApplicationContext applicationContext) {
this(applicationContext, null);
}
/**
* Create a new resource handler registry for the given application context.
* @param applicationContext the Spring application context
* @param contentTypeResolver the content type resolver to use
*/
public ResourceHandlerRegistry(ApplicationContext applicationContext,
CompositeContentTypeResolver contentTypeResolver) {
Assert.notNull(applicationContext, "ApplicationContext is required");
this.applicationContext = applicationContext;
this.contentTypeResolver = contentTypeResolver;
}
/**
* Add a resource handler for serving static resources based on the specified
* URL path patterns. The handler will be invoked for every incoming request
* that matches to one of the specified path patterns.
* <p>Patterns like {@code "/static/**"} or {@code "/css/{filename:\\w+\\.css}"}
* are allowed. See {@link org.springframework.web.util.pattern.ParsingPathMatcher}
* for more details on the syntax.
* @return A {@link ResourceHandlerRegistration} to use to further
* configure the registered resource handler
*/
public ResourceHandlerRegistration addResourceHandler(String... patterns) {
ResourceHandlerRegistration registration =
new ResourceHandlerRegistration(this.applicationContext, patterns);
this.registrations.add(registration);
return registration;
}
/**
* Whether a resource handler has already been registered for the given path pattern.
*/
public boolean hasMappingForPattern(String pathPattern) {
for (ResourceHandlerRegistration registration : this.registrations) {
if (Arrays.asList(registration.getPathPatterns()).contains(pathPattern)) {
return true;
}
}
return false;
}
/**
* Specify the order to use for resource handling relative to other
* {@code HandlerMapping}s configured in the Spring configuration.
* <p>The default value used is {@code Integer.MAX_VALUE-1}.
*/
public ResourceHandlerRegistry setOrder(int order) {
this.order = order;
return this;
}
/**
* Return a handler mapping with the mapped resource handlers; or {@code null} in case
* of no registrations.
*/
protected AbstractHandlerMapping getHandlerMapping() {
if (this.registrations.isEmpty()) {
return null;
}
Map<String, WebHandler> urlMap = new LinkedHashMap<>();
for (ResourceHandlerRegistration registration : this.registrations) {
for (String pathPattern : registration.getPathPatterns()) {
ResourceWebHandler handler = registration.getRequestHandler();
handler.setContentTypeResolver(this.contentTypeResolver);
try {
handler.afterPropertiesSet();
handler.afterSingletonsInstantiated();
}
catch (Exception ex) {
throw new BeanInitializationException("Failed to init ResourceHttpRequestHandler", ex);
}
urlMap.put(pathPattern, handler);
}
}
SimpleUrlHandlerMapping handlerMapping = new SimpleUrlHandlerMapping();
handlerMapping.setOrder(this.order);
handlerMapping.setUrlMap(urlMap);
return handlerMapping;
}
}