1 package org.apache.turbine.util;
2
3
4 import java.io.File;
5
6 /*
7 * Licensed to the Apache Software Foundation (ASF) under one
8 * or more contributor license agreements. See the NOTICE file
9 * distributed with this work for additional information
10 * regarding copyright ownership. The ASF licenses this file
11 * to you under the Apache License, Version 2.0 (the
12 * "License"); you may not use this file except in compliance
13 * with the License. You may obtain a copy of the License at
14 *
15 * http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing,
18 * software distributed under the License is distributed on an
19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
20 * KIND, either express or implied. See the License for the
21 * specific language governing permissions and limitations
22 * under the License.
23 */
24
25
26 import java.util.StringTokenizer;
27
28 import javax.servlet.ServletConfig;
29 import javax.servlet.ServletContext;
30
31 import org.apache.commons.lang3.StringUtils;
32 import org.apache.turbine.Turbine;
33
34 /**
35 * This is where common Servlet manipulation routines should go.
36 *
37 * @author <a href="mailto:gonzalo.diethelm@sonda.com">Gonzalo Diethelm</a>
38 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
39 * @version $Id$
40 */
41 public class ServletUtils
42 {
43 /**
44 * Expands a string that points to a relative path or path list,
45 * leaving it as an absolute path based on the servlet context.
46 * It will return null if the text is empty or the config object
47 * is null.
48 *
49 * @param config The ServletConfig.
50 * @param text The String containing a path or path list.
51 * @return A String with the expanded path or path list.
52 */
53 public static String expandRelative(ServletConfig config,
54 String text)
55 {
56 if (StringUtils.isEmpty(text))
57 {
58 return text;
59 }
60
61 if (config == null)
62 {
63 return null;
64 }
65
66 final String expandedText;
67
68 // attempt to make it relative
69 if (!text.startsWith("/") && !text.startsWith("./")
70 && !text.startsWith("\\") && !text.startsWith(".\\"))
71 {
72 StringBuilder sb = new StringBuilder();
73 sb.append("./");
74 sb.append(text);
75 expandedText = sb.toString();
76 }
77 else
78 {
79 expandedText = text;
80 }
81
82 ServletContext context = config.getServletContext();
83 String base = StringUtils.defaultIfEmpty(context.getRealPath("/"),
84 Turbine.getApplicationRoot());
85
86 if (StringUtils.isEmpty(base))
87 {
88 return expandedText;
89 }
90
91 StringTokenizer tokenizer = new StringTokenizer(expandedText, File.pathSeparator);
92 StringBuilder buffer = new StringBuilder();
93 while (tokenizer.hasMoreTokens())
94 {
95 buffer.append(base).append(tokenizer.nextToken());
96 if (tokenizer.hasMoreTokens())
97 {
98 buffer.append(File.pathSeparator);
99 }
100 }
101 return buffer.toString();
102 }
103 }