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 contract for invoking a chain of {@link ResourceResolver}s where each resolver
26 * is given a reference to the chain allowing it to delegate when necessary.
27 *
28 * @author Jeremy Grelle
29 * @author Rossen Stoyanchev
30 * @author Sam Brannen
31 * @since 4.1
32 */
33 public interface ResourceResolverChain {
34
35 /**
36 * Resolve the supplied request and request path to a {@link Resource} that
37 * exists under one of the given resource locations.
38 *
39 * @param request the current request
40 * @param requestPath the portion of the request path to use
41 * @param locations the locations to search in when looking up resources
42 * @return the resolved resource or {@code null} if unresolved
43 */
44 Resource resolveResource(HttpServletRequest request, String requestPath, List<? extends Resource> locations);
45
46 /**
47 * Resolve the externally facing <em>public</em> URL path for clients to use
48 * to access the resource that is located at the given <em>internal</em>
49 * resource path.
50 *
51 * <p>This is useful when rendering URL links to clients.
52 *
53 * @param resourcePath the internal resource path
54 * @param locations the locations to search in when looking up resources
55 * @return the resolved public URL path or {@code null} if unresolved
56 */
57 String resolveUrlPath(String resourcePath, List<? extends Resource> locations);
58
59 }