1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
<?xml version="1.0"?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!DOCTYPE document [
<!ENTITY project SYSTEM "project.xml">
]>
<document url="resources.html">
&project;
<properties>
<author email="remm@apache.org">Remy Maucherat</author>
<title>The Resources Component</title>
</properties>
<body>
<section name="Table of Contents">
<toc/>
</section>
<section name="Introduction">
<p>The <strong>Resources</strong> element represents the <em>web
application static resources</em>, from which classes will be loaded,
HTML, JSP and the other static files will be served. This allows the webapp
to reside on various mediums other than the filesystem, like compressed
in a WAR file, in a JDBC database, or in a more advanced versioning
repository.</p>
<p>A unified caching engine is provided for all accesses to the webapp
resources made by the servlet container and web applications which use the
container provided mechanisms to access such resources, such as classloader
access, access through the <code>ServletContext</code> interface, or native
access through the <code>DirectoryContext</code> interface.</p>
<p><strong>Note: Running a webapp with non-filesystem based
Resources implementations is only possible when the webapp does not
rely on direct filesystem access to its own resources, and uses the methods
in the ServletContext interface to access them.</strong></p>
<p>A Resources element MAY be nested inside a
<a href="context.html">Context</a> component. If it is not included,
a default filesystem based Resources will be created automatically,
which is sufficient for most requirements.</p>
</section>
<section name="Attributes">
<subsection name="Common Attributes">
<p>All implementations of <strong>Resources</strong>
support the following attributes:</p>
<attributes>
<attribute name="className" required="false">
<p>Java class name of the implementation to use. This class must
implement the <code>javax.naming.directory.DirContext</code> interface.
It is recommended for optimal functionality and performance,
but not mandatory, that the class extend
<code>org.apache.naming.resources.BaseDirContext</code>, as well as
use the special object types provided in the
<code>org.apache.naming.resources</code> for returned objects.
If not specified, the standard value (defined below) will be used.</p>
</attribute>
</attributes>
</subsection>
<subsection name="Standard Implementation">
<p>The standard implementation of <strong>Resources</strong> is
<strong>org.apache.naming.resources.FileDirContext</strong>, and
is configured by its parent Context element.</p>
</subsection>
<subsection name="VirtualDirContext implementation">
<p>This implementation of <strong>Resources</strong> is
<strong>org.apache.naming.resources.VirtualDirContext</strong> and is aimed to be used
during development to deploy a webapp without copying files to a webapp compliant
directory structure.
It extends <code>FileDirContext</code> and supports the following
additional attributes</p>
<attributes>
<attribute name="extraResourcePaths" required="false">
<p>Allows to map a path of the filesystem to a path in the webapp. Multiple
filesystem paths can be mapped to the same path in the webapp. Filesystem
path and virtual path must be separated by an equal signe (=). Pairs of paths
must be separated by a column.</p>
Example: <code>/=/Users/jdoe/mywebapp/src/main/webapp,/=/Users/jdoe/mywebapp/src/main/webapp2,/pictures=/Users/jdoe/sharedpictures</code>
<p>The path to the docBase (as declared in the Context) must not be added here.</p>
<p>This attribute enhances the feature provided by the <code>aliases</code>
attribute of the <strong>StandardContext</strong>.</p>
</attribute>
</attributes>
</subsection>
</section>
<section name="Nested Components">
<p>No components may be nested inside a <strong>Resources</strong> element.</p>
</section>
<section name="Special Features">
<p>No special features are associated with a <strong>Resources</strong>
element.</p>
</section>
</body>
</document>
|
