/*
* Copyright 2002-2016 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.resource;
import java.util.List;
import reactor.core.publisher.Mono;
import org.springframework.core.io.Resource;
import org.springframework.web.server.ServerWebExchange;
/**
* A strategy for resolving a request to a server-side resource.
*
* <p>Provides mechanisms for resolving an incoming request to an actual
* {@link Resource} and for obtaining the
* public URL path that clients should use when requesting the resource.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
public interface ResourceResolver {
/**
* Resolve the supplied request and request path to a {@link Resource} that
* exists under one of the given resource locations.
* @param exchange the current exchange
* @param requestPath the portion of the request path to use
* @param locations the locations to search in when looking up resources
* @param chain the chain of remaining resolvers to delegate to
* @return the resolved resource or an empty {@code Mono} if unresolved
*/
Mono<Resource> resolveResource(ServerWebExchange exchange, String requestPath,
List<? extends Resource> locations, ResourceResolverChain chain);
/**
* Resolve the externally facing <em>public</em> URL path for clients to use
* to access the resource that is located at the given <em>internal</em>
* resource path.
* <p>This is useful when rendering URL links to clients.
* @param resourcePath the internal resource path
* @param locations the locations to search in when looking up resources
* @param chain the chain of resolvers to delegate to
* @return the resolved public URL path or an empty {@code Mono} if unresolved
*/
Mono<String> resolveUrlPath(String resourcePath, List<? extends Resource> locations,
ResourceResolverChain chain);
}