1 /*
2 * Copyright 2002-2014 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.web.servlet.resource;
18
19 import java.util.List;
20 import javax.servlet.http.HttpServletRequest;
21
22 import org.springframework.core.io.Resource;
23
24 /**
25 * A strategy for resolving a request to a server-side resource.
26 *
27 * <p>Provides mechanisms for resolving an incoming request to an actual
28 * {@link org.springframework.core.io.Resource} and for obtaining the public
29 * URL path that clients should use when requesting the resource.
30 *
31 * @author Jeremy Grelle
32 * @author Rossen Stoyanchev
33 * @author Sam Brannen
34 * @since 4.1
35 * @see org.springframework.web.servlet.resource.ResourceResolverChain
36 */
37 public interface ResourceResolver {
38
39 /**
40 * Resolve the supplied request and request path to a {@link Resource} that
41 * exists under one of the given resource locations.
42 *
43 * @param request the current request
44 * @param requestPath the portion of the request path to use
45 * @param locations the locations to search in when looking up resources
46 * @param chain the chain of remaining resolvers to delegate to
47 * @return the resolved resource or {@code null} if unresolved
48 */
49 Resource resolveResource(HttpServletRequest request, String requestPath, List<? extends Resource> locations,
50 ResourceResolverChain chain);
51
52 /**
53 * Resolve the externally facing <em>public</em> URL path for clients to use
54 * to access the resource that is located at the given <em>internal</em>
55 * resource path.
56 *
57 * <p>This is useful when rendering URL links to clients.
58 *
59 * @param resourcePath the internal resource path
60 * @param locations the locations to search in when looking up resources
61 * @param chain the chain of resolvers to delegate to
62 * @return the resolved public URL path or {@code null} if unresolved
63 */
64 String resolveUrlPath(String resourcePath, List<? extends Resource> locations, ResourceResolverChain chain);
65
66 }