1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.scxml.env.servlet;
18
19 import javax.servlet.ServletContext;
20
21 import org.apache.commons.scxml.PathResolver;
22
23 /**
24 * A wrapper around ServletContext that implements PathResolver.
25 *
26 * @see org.apache.commons.scxml.PathResolver
27 */
28 public class ServletContextResolver implements PathResolver {
29
30 /** Cannot accept a null ServletContext, it will just throw
31 * NullPointerException down the road. */
32 private static final String ERR_SERVLET_CTX_NULL =
33 "ServletContextResolver cannot be instantiated with a null"
34 + " ServletContext";
35
36 /** The SevletContext we will use to resolve paths. */
37 private ServletContext ctx = null;
38
39 /**
40 * Constructor.
41 *
42 * @param ctx The ServletContext instance for this web application.
43 */
44 public ServletContextResolver(final ServletContext ctx) {
45 if (ctx == null) {
46 throw new IllegalArgumentException(ERR_SERVLET_CTX_NULL);
47 }
48 this.ctx = ctx;
49 }
50
51 /**
52 * Delegates to the underlying ServletContext's getRealPath(String).
53 *
54 * @param ctxPath context sensitive path, can be a relative URL
55 * @return resolved path (an absolute URL) or <code>null</code>
56 * @see org.apache.commons.scxml.PathResolver#resolvePath(java.lang.String)
57 */
58 public String resolvePath(final String ctxPath) {
59 return ctx.getRealPath(ctxPath);
60 }
61
62 /**
63 * Retrieve the PathResolver rooted at the given path.
64 *
65 * @param ctxPath context sensitive path, can be a relative URL
66 * @return returns a new resolver rooted at ctxPath
67 * @see org.apache.commons.scxml.PathResolver#getResolver(java.lang.String)
68 */
69 public PathResolver getResolver(final String ctxPath) {
70 return this;
71 }
72
73 }
74