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Java > Open Source Codes > org > objectweb > jonas_lib > loader > locator > Locator


1 /**
2  * JOnAS: Java(TM) Open Application Server
3  * Copyright (C) 1999 Bull S.A.
4  * Contact: jonas-team@objectweb.org
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
19  * USA
20  *
21  * Initial developer(s): Guillaume SAUTHIER
22  * --------------------------------------------------------------------------
23  * $Id: Locator.java,v 1.3 2004/04/19 13:49:09 sauthieg Exp $
24  * --------------------------------------------------------------------------
25  */
26
27 package org.objectweb.jonas_lib.loader.locator;
28
29 import java.util.List JavaDoc;
30 import java.net.URL JavaDoc;
31 import java.io.IOException JavaDoc;
32
33 /**
34  * A <code>Locator</code> is used to hide System specific
35  * when looking for a file.
36  *
37  * @author Guillaume Sauthier
38  */
39 public abstract class Locator {
40
41     /**
42      * Returns true when file was found.
43      *
44      * @param path the path to the file to look up
45      *
46      * @return true when file was found, otherwise false.
47      */
48     public abstract boolean hasFile(String JavaDoc path);
49
50     /**
51      * Returns true when directory was found.
52      *
53      * @param path the path to the directory to look up
54      *
55      * @return true when directory was found, otherwise false.
56      */
57     public abstract boolean hasDirectory(String JavaDoc path);
58
59     /**
60      * Returns a list of filename stored in path.
61      *
62      * @param path the path to the directory where looking for files
63      *
64      * @return a list of filename stored in path.
65      */
66     public abstract List JavaDoc listContent(String JavaDoc path);
67
68     /**
69      * Return a new Locator in function of the URL type.
70      * an URL pointing to a jar file will return a <code>JarFileLocator</code>
71      * and an URL pointing to a directory file will return a <code>DirFileLocator</code>.
72      *
73      * @param url the base URL
74      *
75      * @return a new Locator in function of the URL type.
76      *
77      * @throws IOException when cannot find a specialized locator for the given URL.
78      */
79     public static Locator getLocator(URL JavaDoc url) throws IOException JavaDoc {
80
81         String JavaDoc path = url.getPath();
82         if (path.matches(".*\\..ar")) {
83             // jar detected if path ends with .?ar (*.jar, *.war, *.ear)
84 return new JarFileLocator(url);
85         } else if (path.endsWith("/")) {
86             // directory detected if url ends with a separator /
87 return new DirLocator(url);
88         } else {
89             String JavaDoc err = "Unsupported URL '" + url + "' support "
90                 + "only jar archive and directory";
91             throw new IOException JavaDoc(err);
92         }
93     }
94 }
95
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