1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.myfaces.shared.resource;
20
21 import java.io.IOException;
22 import java.io.InputStream;
23 import java.net.URL;
24 import java.util.Comparator;
25
26 /**
27 * Base class for resource loaders. Resource loaders can lookup resources
28 * as URLs from arbitrary locations, including JAR files.
29 *
30 * @author Leonardo Uribe (latest modification by $Author: lu4242 $)
31 * @version $Revision: 1212586 $ $Date: 2011-12-09 14:16:55 -0500 (Fri, 09 Dec 2011) $
32 */
33 public abstract class ResourceLoader
34 {
35
36 public static final String VERSION_INVALID = "INVALID";
37
38 private String _prefix;
39
40 public ResourceLoader(String prefix)
41 {
42 _prefix = prefix;
43 }
44
45 public abstract String getResourceVersion(String path);
46
47 /**
48 * Return the max available version found (if exists) or
49 * return null if no version available.
50 */
51 public abstract String getLibraryVersion(String path);
52
53 /**
54 * Return the max available version found (if exists) or
55 * return null if no version available.
56 */
57 public abstract URL getResourceURL(ResourceMeta resourceMeta);
58
59 public abstract InputStream getResourceInputStream(ResourceMeta resourceMeta);
60
61 public abstract ResourceMeta createResourceMeta(String prefix, String libraryName, String libraryVersion,
62 String resourceName, String resourceVersion);
63
64 public abstract boolean libraryExists(String libraryName);
65
66 public boolean resourceExists(ResourceMeta resourceMeta)
67 {
68 return (getResourceURL(resourceMeta) != null);
69 }
70
71 private Comparator<String> _versionComparator = null;
72
73 protected Comparator<String> getVersionComparator()
74 {
75 if (_versionComparator == null)
76 {
77 _versionComparator = new VersionComparator();
78 }
79 return _versionComparator;
80 }
81
82 protected void setVersionComparator(Comparator<String> versionComparator)
83 {
84 _versionComparator = versionComparator;
85 }
86
87 public class VersionComparator implements Comparator<String>
88 {
89
90 public int compare(String s1, String s2)
91 {
92 int n1 = 0;
93 int n2 = 0;
94 String o1 = s1;
95 String o2 = s2;
96
97 boolean p1 = true;
98 boolean p2 = true;
99
100 while (n1 == n2 && (p1 || p2))
101 {
102 int i1 = o1.indexOf('_');
103 int i2 = o2.indexOf('_');
104 if (i1 < 0)
105 {
106 if (o1.length() > 0)
107 {
108 p1 = false;
109 n1 = Integer.valueOf(o1);
110 o1 = "";
111 }
112 else
113 {
114 p1 = false;
115 n1 = 0;
116 }
117 }
118 else
119 {
120 n1 = Integer.valueOf(o1.substring(0, i1));
121 o1 = o1.substring(i1 + 1);
122 }
123 if (i2 < 0)
124 {
125 if (o2.length() > 0)
126 {
127 p2 = false;
128 n2 = Integer.valueOf(o2);
129 o2 = "";
130 }
131 else
132 {
133 p2 = false;
134 n2 = 0;
135 }
136 }
137 else
138 {
139 n2 = Integer.valueOf(o2.substring(0, i2));
140 o2 = o2.substring(i2 + 1);
141 }
142 }
143
144 if (n1 == n2)
145 {
146 return s1.length() - s2.length();
147 }
148 return n1 - n2;
149 }
150 }
151
152 public String getPrefix()
153 {
154 return _prefix;
155 }
156
157 public void setPrefix(String prefix)
158 {
159 _prefix = prefix;
160 }
161 }