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5 The Apache Tomcat Servlet/JSP Container
Hongqing Liu71898292014-10-15 13:31:32 +08006 " border="0"></a></td><td><h1><font face="arial,helvetica,sanserif">Apache Tomcat 6.0</font></h1><font face="arial,helvetica,sanserif">Version 6.0.41, May 19 2014</font></td><td><!--APACHE LOGO--><a href="http://www.apache.org/"><img src="../images/asf-logo.gif" align="right" alt="Apache Logo" border="0"></a></td></tr></table><table border="0" width="100%" cellspacing="4"><!--HEADER SEPARATOR--><tr><td colspan="2"><hr noshade="noshade" size="1"></td></tr><tr><!--LEFT SIDE NAVIGATION--><td width="20%" valign="top" nowrap="nowrap" class="noPrint"><p><strong>Links</strong></p><ul><li><a href="../index.html">Docs Home</a></li><li><a href="index.html">Config Ref. Home</a></li></ul><p><strong>Top Level Elements</strong></p><ul><li><a href="server.html">Server</a></li><li><a href="service.html">Service</a></li></ul><p><strong>Executors</strong></p><ul><li><a href="executor.html">Executor</a></li></ul><p><strong>Connectors</strong></p><ul><li><a href="http.html">HTTP</a></li><li><a href="ajp.html">AJP</a></li></ul><p><strong>Containers</strong></p><ul><li><a href="context.html">Context</a></li><li><a href="engine.html">Engine</a></li><li><a href="host.html">Host</a></li><li><a href="cluster.html">Cluster</a></li></ul><p><strong>Nested Components</strong></p><ul><li><a href="globalresources.html">Global Resources</a></li><li><a href="listeners.html">Listeners</a></li><li><a href="loader.html">Loader</a></li><li><a href="manager.html">Manager</a></li><li><a href="realm.html">Realm</a></li><li><a href="resources.html">Resources</a></li><li><a href="valve.html">Valve</a></li></ul><p><strong>Cluster Elements</strong></p><ul><li><a href="cluster.html">Cluster</a></li><li><a href="cluster-manager.html">Manager</a></li><li><a href="cluster-channel.html">Channel</a></li><li><a href="cluster-membership.html">Channel/Membership</a></li><li><a href="cluster-sender.html">Channel/Sender</a></li><li><a href="cluster-receiver.html">Channel/Receiver</a></li><li><a href="cluster-interceptor.html">Channel/Interceptor</a></li><li><a href="cluster-valve.html">Valve</a></li><li><a href="cluster-deployer.html">Deployer</a></li><li><a href="cluster-listener.html">ClusterListener</a></li></ul><p><strong>web.xml</strong></p><ul><li><a href="filter.html">Filter</a></li></ul><p><strong>Other</strong></p><ul><li><a href="systemprops.html">System properties</a></li></ul></td><!--RIGHT SIDE MAIN BODY--><td width="80%" valign="top" align="left" id="mainBody"><h1>Apache Tomcat Configuration Reference</h1><h2>The Context Container</h2><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Table of Contents"><!--()--></a><a name="Table_of_Contents"><strong>Table of Contents</strong></a></font></td></tr><tr><td><blockquote>
Hongqing Liufd5ee812014-05-10 16:32:51 +08007<ul><li><a href="#Introduction">Introduction</a><ol><li><a href="#Naming">Naming</a></li><li><a href="#Defining_a_context">Defining a context</a></li></ol></li><li><a href="#Attributes">Attributes</a><ol><li><a href="#Common_Attributes">Common Attributes</a></li><li><a href="#Standard_Implementation">Standard Implementation</a></li></ol></li><li><a href="#Nested_Components">Nested Components</a></li><li><a href="#Special_Features">Special Features</a><ol><li><a href="#Logging">Logging</a></li><li><a href="#Access_Logs">Access Logs</a></li><li><a href="#Automatic_Context_Configuration">Automatic Context Configuration</a></li><li><a href="#Context_Parameters">Context Parameters</a></li><li><a href="#Environment_Entries">Environment Entries</a></li><li><a href="#Lifecycle_Listeners">Lifecycle Listeners</a></li><li><a href="#Request_Filters">Request Filters</a></li><li><a href="#Resource_Definitions">Resource Definitions</a></li><li><a href="#Resource_Links">Resource Links</a></li><li><a href="#Transaction">Transaction</a></li></ol></li></ul>
8</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote>
9
10 <blockquote><em>
11 <p>The description below uses the variable name $CATALINA_BASE to refer the
12 base directory against which most relative paths are resolved. If you have
13 not configured Tomcat 6 for multiple instances by setting a CATALINA_BASE
14 directory, then $CATALINA_BASE will be set to the value of $CATALINA_HOME,
15 the directory into which you have installed Tomcat 6.</p>
16 </em></blockquote>
17
18 <p>The <strong>Context</strong> element represents a <em>web
19 application</em>, which is run within a particular virtual host.
20 Each web application is based on a <em>Web Application Archive</em>
21 (WAR) file, or a corresponding directory containing the corresponding
22 unpacked contents, as described in the Servlet Specification (version
23 2.2 or later). For more information about web application archives,
24 you can download the
25 <a href="http://wiki.apache.org/tomcat/Specifications">Servlet
26 Specification</a>, and review the Tomcat
27 <a href="../appdev/index.html">Application Developer's Guide</a>.</p>
28
29 <p>The web application used to process each HTTP request is selected
30 by Catalina based on matching the longest possible prefix of the
31 Request URI against the <em>context path</em> of each defined Context.
32 Once selected, that Context will select an appropriate servlet to
33 process the incoming request, according to the servlet mappings defined
34 in the <em>web application deployment descriptor</em> file (which MUST
35 be located at <code>/WEB-INF/web.xml</code> within the web app's
36 directory hierarchy).</p>
37
38 <p>You may define as many <strong>Context</strong> elements as you
39 wish. Each such Context MUST have a unique context path within a virtual
40 host. In
41 addition, a Context must be present with a context path equal to
42 a zero-length string. This Context becomes the <em>default</em>
43 web application for this virtual host, and is used to process all
44 requests that do not match any other Context's context path.</p>
45
46 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Naming"><strong>Naming</strong></a></font></td></tr><tr><td><blockquote>
47 <p>When <code>autoDeploy</code> or <code>deployOnStartup</code> operations
48 are performed by a Host, the web application is specified by a context XML
49 file in <a href="host.html">Host</a>'s <code>xmlBase</code>
50 directory or by a WAR file or a directory file in Host's
51 <code>appBase</code> directory.
52 In this case the context path is derived from the name of the file that
53 is being deployed. Consequently, the context path <strong>may not</strong>
54 be defined in a <code>META-INF/context.xml</code> embedded in
55 the application. There is, therefore, a close relationship between the
56 <em>context path</em> and
57 the <em>base file name</em> (the name minus <code>.war</code> or
58 <code>.xml</code> extension) of the file.</p>
59
60 <p>Let us assume that you want to deploy your application to respond to
61 requests to URIs starting with certain context path. According to the
62 Servlet specification, the context path may be an empty string, or a
63 string starting with '/'. The rules to define the names for this context
64 path are the following:</p>
65
66 <ul>
67 <li>If the context path is a zero length string, the <em>base name</em> is
68 <code>"ROOT"</code> (uppercase)</li>
69 <li>If the context path is not a zero length string, the <em>base
70 name</em> is the context path with the leading '/' removed and any
71 remaining '/' characters in the path replaced with '#'.</li>
72 </ul>
73
74 <p>To help clarify these rules, some examples are given in the following
75 table.</p>
76
77 <table class="detail-table">
78 <tr>
79 <td bgcolor="#039acc" valign="top"><font color="#000000" size="-1" face="arial,helvetica,sanserif">Context Path</font></td>
80 <td bgcolor="#039acc" valign="top"><font color="#000000" size="-1" face="arial,helvetica,sanserif">Base File Name</font></td>
81 </tr>
82 <tr><td bgcolor="#a0ddf0" valign="top" align="left"><font color="#000000" size="-1" face="arial,helvetica,sanserif">/foo</font></td><td bgcolor="#a0ddf0" valign="top" align="left"><font color="#000000" size="-1" face="arial,helvetica,sanserif">foo</font></td></tr>
83 <tr>
84 <td bgcolor="#a0ddf0" valign="top" align="left"><font color="#000000" size="-1" face="arial,helvetica,sanserif">/foo/bar</font></td><td bgcolor="#a0ddf0" valign="top" align="left"><font color="#000000" size="-1" face="arial,helvetica,sanserif">foo#bar</font></td>
85 </tr>
86 <tr>
87 <td bgcolor="#a0ddf0" valign="top" align="left"><font color="#000000" size="-1" face="arial,helvetica,sanserif"><i>Empty String</i></font></td>
88 <td bgcolor="#a0ddf0" valign="top" align="left"><font color="#000000" size="-1" face="arial,helvetica,sanserif">ROOT</font></td>
89 </tr>
90 </table>
91
92 <p>If you want to deploy a WAR file or a directory using a context path that
93 is not related to the base file name then one of the following options must
94 be used to prevent double-deployment:
95 </p>
96 <ul>
97 <li>Disable autoDeploy and deployOnStartup and define all
98 <strong>Context</strong>s in server.xml</li>
99 <li>Locate the WAR and/or directory outside of the Host's appBase and use
100 a context.xml file with a docBase attribute to define it.</li>
101 </ul>
102 </blockquote></td></tr></table>
103
104 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Defining a context"><!--()--></a><a name="Defining_a_context"><strong>Defining a context</strong></a></font></td></tr><tr><td><blockquote>
105 <p><b>It is NOT recommended to place
106 &lt;Context&gt; elements directly in the server.xml file.</b> This
107 is because it makes modifying the <strong>Context</strong> configuration
108 more invasive since the main <code>conf/server.xml</code> file cannot be
109 reloaded without restarting Tomcat.</p>
110
111 <p>Individual <strong>Context</strong> elements may be explicitly defined:
112 </p>
113 <ul>
114 <li>In an individual file at <code>/META-INF/context.xml</code> inside the
115 application files. In Tomcat 6 this file is automatically copied to
116 <code>$CATALINA_BASE/conf/[enginename]/[hostname]/</code> and renamed to
117 application's base file name plus a ".xml" extension.
118 (This automated copying became optional in Tomcat 7).
119 </li>
120 <li>In individual files (with a ".xml" extension) in the
121 <code>$CATALINA_BASE/conf/[enginename]/[hostname]/</code> directory.
122 The context path will be derived from the base name of the file
123 (the file name less the .xml extension). This file will always take precedence
124 over any context.xml file packaged in the web application's META-INF
125 directory.</li>
126 <li>Inside a <a href="host.html">Host</a> element in the main
127 <code>conf/server.xml</code>.</li>
128 </ul>
129
130 <p>Default <strong>Context</strong> elements may be defined that apply to
131 multiple web applications. Configuration for an individual web application
132 will override anything configured in one of these defaults. Any nested
133 elements, e.g. &lt;Resource&gt; elements, that are defined in a default
134 <strong>Context</strong> will be created once for each
135 <strong>Context</strong> to which the default applies. They will <b>not</b> be
136 shared between <strong>Context</strong> elements.
137 </p>
138 <ul>
139 <li>In the <code>$CATALINA_BASE/conf/context.xml</code> file:
140 the Context element information will be loaded by all web applications.</li>
141 <li>In the
142 <code>$CATALINA_BASE/conf/[enginename]/[hostname]/context.xml.default</code>
143 file: the Context element information will be loaded by all web applications
144 of that host.</li>
145 </ul>
146
147 <p>With the exception of server.xml, files that define <strong>Context
148 </strong> elements may only define a single <strong>Context</strong> element.
149 </p>
150
151 <p>In addition to explicitly specified Context elements, there are
152 several techniques by which Context elements can be created automatically
153 for you. See <a href="host.html#Automatic_Application_Deployment">
154 Automatic Application Deployment</a> and
155 <a href="host.html#User_Web_Applications">User Web Applications</a>
156 for more information.</p>
157
158 <p>To define multiple contexts that use a single WAR file or directory,
159 use one of the options described in the <a href="#Naming">Naming</a>
160 section above for creating a <strong>Context</strong> that has a path
161 that is not related to the base file name.</p>
162 </blockquote></td></tr></table>
163
164</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Attributes"><strong>Attributes</strong></a></font></td></tr><tr><td><blockquote>
165
166 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Common Attributes"><!--()--></a><a name="Common_Attributes"><strong>Common Attributes</strong></a></font></td></tr><tr><td><blockquote>
167
168 <p>All implementations of <strong>Context</strong>
169 support the following attributes:</p>
170
171 <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code>backgroundProcessorDelay</code></td><td align="left" valign="center">
172 <p>This value represents the delay in seconds between the
173 invocation of the backgroundProcess method on this context and
174 its child containers, including all wrappers.
175 Child containers will not be invoked if their delay value is not
176 negative (which would mean they are using their own processing
177 thread). Setting this to a positive value will cause
178 a thread to be spawn. After waiting the specified amount of time,
179 the thread will invoke the backgroundProcess method on this host
180 and all its child containers. A context will use background
181 processing to perform session expiration and class monitoring for
182 reloading. If not specified, the default value for this attribute is
183 -1, which means the context will rely on the background processing
184 thread of its parent host.</p>
185 </td></tr><tr><td align="left" valign="center"><code>className</code></td><td align="left" valign="center">
186 <p>Java class name of the implementation to use. This class must
187 implement the <code>org.apache.catalina.Context</code> interface.
188 If not specified, the standard value (defined below) will be used.</p>
189 </td></tr><tr><td align="left" valign="center"><code>cookies</code></td><td align="left" valign="center">
190 <p>Set to <code>true</code> if you want cookies to be used for
191 session identifier communication if supported by the client (this
192 is the default). Set to <code>false</code> if you want to disable
193 the use of cookies for session identifier communication, and rely
194 only on URL rewriting by the application.</p>
195 </td></tr><tr><td align="left" valign="center"><code>crossContext</code></td><td align="left" valign="center">
196 <p>Set to <code>true</code> if you want calls within this application
197 to <code>ServletContext.getContext()</code> to successfully return a
198 request dispatcher for other web applications running on this virtual
199 host. Set to <code>false</code> (the default) in security
200 conscious environments, to make <code>getContext()</code> always
201 return <code>null</code>.</p>
202 </td></tr><tr><td align="left" valign="center"><code>disableURLRewriting</code></td><td align="left" valign="center">
203 <p>Set to <code>true</code> to disable support for using URL rewriting
204 to track session IDs for clients of this Context. URL rewriting is an
205 optional component of the servlet 2.5 specification but disabling URL
206 rewriting will result in non-compliant behaviour since the specification
207 requires that there <em>must</em> be a way to retain sessions if the
208 client doesn't allow session cookies. If not specified, the
209 specification compliant default value of <code>false</code> will be
210 used.</p>
211 </td></tr><tr><td align="left" valign="center"><strong><code>docBase</code></strong></td><td align="left" valign="center">
212 <p>The <em>Document Base</em> (also known as the <em>Context
213 Root</em>) directory for this web application, or the pathname
214 to the web application archive file (if this web application is
215 being executed directly from the WAR file). You may specify
216 an absolute pathname for this directory or WAR file, or a pathname
217 that is relative to the <code>appBase</code> directory of the
218 owning <a href="host.html">Host</a>.</p>
219 <p>The value of this field must not be set unless the Context element is
220 defined in server.xml or the <code>docBase</code> is not located under
221 the <a href="host.html">Host</a>'s <code>appBase</code>.</p>
222 <p>If a symbolic link is used for docBase then changes to the
223 symbolic link will only be effective after a Tomcat restart or
224 by undeploying and redeploying the context. A context reload is not
225 sufficient.</p>
226 </td></tr><tr><td align="left" valign="center"><code>override</code></td><td align="left" valign="center">
227 <p>Set to <code>true</code> to have explicit settings in this
228 Context element override any corresponding settings in either the global
229 or <a href="host.html">Host</a> default contexts. By default, settings
230 from a default context will be used.</p>
231 </td></tr><tr><td align="left" valign="center"><code>privileged</code></td><td align="left" valign="center">
232 <p>Set to <code>true</code> to allow this context to use container
233 servlets, like the manager servlet. Use of the <code>privileged</code>
234 attribute will change the context's parent class loader to be the
235 <em>Server</em> class loader rather than the <em>Shared</em> class
236 loader. Note that in a default installation, the <em>Common</em> class
237 loader is used for both the <em>Server</em> and the <em>Shared</em>
238 class loaders.</p>
239 </td></tr><tr><td align="left" valign="center"><code>path</code></td><td align="left" valign="center">
240 <p>The <em>context path</em> of this web application, which is
241 matched against the beginning of each request URI to select the
242 appropriate web application for processing. All of the context paths
243 within a particular <a href="host.html">Host</a> must be unique.
244 If you specify a context path of an empty string (""), you are
245 defining the <em>default</em> web application for this Host, which
246 will process all requests not assigned to other Contexts.</p>
247 <p>This attribute must only be used when statically defining a Context
248 in server.xml. In all other circumstances, the path will be inferred
249 from the filenames used for either the .xml context file or the docBase.
250 </p>
251 <p>Even when statically defining a Context in server.xml, this attribute
252 must not be set unless either the docBase is not located under the
253 <a href="host.html">Host</a>'s <code>appBase</code> or both
254 <code>deployOnStartup</code> and <code>autoDeploy</code> are false. If
255 this rule is not followed, double deployment is likely to result.</p>
256 </td></tr><tr><td align="left" valign="center"><code>reloadable</code></td><td align="left" valign="center">
257 <p>Set to <code>true</code> if you want Catalina to monitor classes in
258 <code>/WEB-INF/classes/</code> and <code>/WEB-INF/lib</code> for
259 changes, and automatically reload the web application if a change
260 is detected. This feature is very useful during application
261 development, but it requires significant runtime overhead and is
262 not recommended for use on deployed production applications. That's
263 why the default setting for this attribute is <i>false</i>. You
264 can use the <a href="../manager-howto.html">Manager</a> web
265 application, however, to trigger reloads of deployed applications
266 on demand.</p>
267 </td></tr><tr><td align="left" valign="center"><code>sessionCookieDomain</code></td><td align="left" valign="center">
268 <p>The domain to be used for all session cookies created for this
269 Context. If not set, no domain will be specified for session cookies.
270 </p>
271 </td></tr><tr><td align="left" valign="center"><code>sessionCookieName</code></td><td align="left" valign="center">
272 <p>The name to be used for all session cookies created for this
273 Context. If not set, the default of JSESSIONID will be used. Note that
274 this default will be overridden by the
275 <strong>org.apache.catalina.SESSION_COOKIE_NAME</strong> system
276 property.</p>
277 </td></tr><tr><td align="left" valign="center"><code>sessionCookiePath</code></td><td align="left" valign="center">
278 <p>The path to be used for all session cookies created for this
279 Context. If not set, the context path will be used. Note that this will
280 be overridden by the <strong>emptySessionPath</strong> attribute on the
281 connector used to access this Context.</p>
282 </td></tr><tr><td align="left" valign="center"><code>tldValidation</code></td><td align="left" valign="center">
283 <p>If the value of this flag is <code>true</code>, the TLD files
284 will be XML validated on context startup. If the
285 <code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code>
286 <a href="systemprops.html">system property</a> is set to
287 <code>true</code>, the default value of this attribute will be
288 <code>true</code>, else the default value will be <code>false</code>.
289 Setting this attribute to <code>true</code> will incur a performance
290 penalty.</p>
291 </td></tr><tr><td align="left" valign="center"><code>useHttpOnly</code></td><td align="left" valign="center">
292 <p>Should the HttpOnly flag be set on session cookies to prevent client
293 side script from accessing the session ID? Defaults to
294 <code>false</code>.</p>
295 </td></tr><tr><td align="left" valign="center"><code>wrapperClass</code></td><td align="left" valign="center">
296 <p>Java class name of the <code>org.apache.catalina.Wrapper</code>
297 implementation class that will be used for servlets managed by this
298 Context. If not specified, a standard default value will be used.</p>
299 </td></tr><tr><td align="left" valign="center"><code>xmlBlockExternal</code></td><td align="left" valign="center">
300 <p>If the value of this flag is <code>true</code>, the parsing of
301 <code>web.xml</code>, <code>web-fragment.xml</code>, <code>*.tld</code>,
302 <code>*.jspx</code>, <code>*.tagx</code> and <code>tagPlugins.xml</code>
303 files for this web application will not permit external entities to be
Hongqing Liu71898292014-10-15 13:31:32 +0800304 loaded. If not specified, the default value of <code>true</code> will
305 be used.</p>
Hongqing Liufd5ee812014-05-10 16:32:51 +0800306 </td></tr><tr><td align="left" valign="center"><code>xmlNamespaceAware</code></td><td align="left" valign="center">
307 <p>If the value of this flag is <code>true</code>, the parsing of the
308 <code>web.xml</code> file for this web application will be
309 namespace-aware. Note that <code>*.tld</code>, <code>*.jspx</code> and
310 <code>*.tagx</code> files are always parsed using a namespace-aware
311 parser and that the <code>tagPlugins.xml</code> file (if any) is never
312 parsed using a namespace-aware parser. Note also that if you turn this
313 flag on, you should probably also turn <code>xmlValidation</code> on. If
314 the <code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code>
315 <a href="systemprops.html">system property</a> is set to
316 <code>true</code>, the default value of this attribute will be
317 <code>true</code>, else the default value will be <code>false</code>.
318 Setting this attribute to <code>true</code> will incur a performance
319 penalty.</p>
320 </td></tr><tr><td align="left" valign="center"><code>xmlValidation</code></td><td align="left" valign="center">
321 <p>If the value of this flag is <code>true</code>, the parsing of the
322 <code>web.xml</code> file for this web application will use a validating
323 parser. If the
324 <code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code>
325 <a href="systemprops.html">system property</a> is set to
326 <code>true</code>, the default value of this attribute will be
327 <code>true</code>, else the default value will be <code>false</code>.
328 Setting this attribute to <code>true</code> will incur a performance
329 penalty.</p>
330 </td></tr></table>
331
332 </blockquote></td></tr></table>
333
334
335 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Standard Implementation"><!--()--></a><a name="Standard_Implementation"><strong>Standard Implementation</strong></a></font></td></tr><tr><td><blockquote>
336
337 <p>The standard implementation of <strong>Context</strong> is
338 <strong>org.apache.catalina.core.StandardContext</strong>.
339 It supports the following additional attributes (in addition to the
340 common attributes listed above):</p>
341
342 <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code>allowLinking</code></td><td align="left" valign="center">
343 <p>If the value of this flag is <code>true</code>, symlinks will be
344 allowed inside the web application, pointing to resources outside the
345 web application base path. If not specified, the default value
346 of the flag is <code>false</code>.</p>
347 <p><b>NOTE: This flag MUST NOT be set to true on the Windows platform
348 (or any other OS which does not have a case sensitive filesystem),
349 as it will disable case sensitivity checks, allowing JSP source code
350 disclosure, among other security problems.</b></p>
351 </td></tr><tr><td align="left" valign="center"><code>antiJARLocking</code></td><td align="left" valign="center">
352 <p>If true, the Tomcat classloader will take extra measures to avoid
353 JAR file locking when resources are accessed inside JARs through URLs.
354 This will impact startup time of applications, but could prove to be
355 useful on platforms or configurations where file locking can occur.
356 If not specified, the default value is <code>false</code>.</p>
357
358 <p><code>antiJARLocking</code> is a subset of
359 <code>antiResourceLocking</code> and therefore, to prevent duplicate
360 work and possible issues, only one of these attributes should be set
361 to <code>true</code> at any one time.</p>
362 </td></tr><tr><td align="left" valign="center"><code>antiResourceLocking</code></td><td align="left" valign="center">
363 <p>If true, Tomcat will prevent any file locking.
364 This will significantly impact startup time of applications,
365 but allows full webapp hot deploy and undeploy on platforms
366 or configurations where file locking can occur.
367 If not specified, the default value is <code>false</code>.</p>
368
369 <p><code>antiJARLocking</code> is a subset of
370 <code>antiResourceLocking</code> and therefore, to prevent duplicate
371 work and possible issues, only one of these attributes should be set
372 to <code>true</code> at any one time.</p>
373
374 <p>Please note that setting this to <code>true</code> has some side
375 effects, including the disabling of JSP reloading in a running server:
376 see <a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=37668">
377 Bugzilla 37668</a>.</p>
378
379 <p>Please note that setting this flag to true in applications that are
380 outside the appBase for the Host (the <code>webapps</code> directory
381 by default) will cause the application to be <strong>deleted</strong> on
382 Tomcat shutdown. You probably don't want to do this, so think twice
383 before setting antiResourceLocking=true on a webapp that's outside the
384 appBase for its Host.</p>
385 </td></tr><tr><td align="left" valign="center"><code>cacheMaxSize</code></td><td align="left" valign="center">
386 <p>Maximum size of the static resource cache in kilobytes.
387 If not specified, the default value is <code>10240</code>
388 (10 megabytes).</p>
389 </td></tr><tr><td align="left" valign="center"><code>cacheObjectMaxSize</code></td><td align="left" valign="center">
390 <p>Maximum size of the static resource that will be placed in the cache.
391 If not specified, the default value is <code>512</code>
392 (512 kilobytes). If this value is greater than
393 <code>cacheMaxSize/20</code> it will be reduced to
394 <code>cacheMaxSize/20</code>.</p>
395 </td></tr><tr><td align="left" valign="center"><code>cacheTTL</code></td><td align="left" valign="center">
396 <p>Amount of time in milliseconds between cache entries revalidation.
397 If not specified, the default value is <code>5000</code>
398 (5 seconds).</p>
399 </td></tr><tr><td align="left" valign="center"><code>cachingAllowed</code></td><td align="left" valign="center">
400 <p>If the value of this flag is <code>true</code>, the cache for static
401 resources will be used. If not specified, the default value
402 of the flag is <code>true</code>.</p>
403 </td></tr><tr><td align="left" valign="center"><code>caseSensitive</code></td><td align="left" valign="center">
404 <p><strong>Deprecated.</strong> This option is removed in Tomcat 7
405 onwards where the default of <code>true</code> is always used.</p>
406 <p>If the value of this flag is <code>false</code>, all case sensitivity
407 checks will be disabled. If not
408 specified, the default value of the flag is <code>true</code>.</p>
409 <p><b>NOTE: This flag MUST NOT be set to false on the Windows platform
410 (or any other OS which does not have a case sensitive filesystem),
411 as it will disable case sensitivity checks, allowing JSP source code
412 disclosure, among other security problems.</b></p>
413 </td></tr><tr><td align="left" valign="center"><code>clearReferencesHttpClientKeepAliveThread</code></td><td align="left" valign="center">
414 <p>If <code>true</code> and an <code>sun.net.www.http.HttpClient</code>
415 keep-alive timer thread has been started by this web application and is
416 still running, Tomcat will change the context class loader for that
417 thread from the current <code>WebappClassLoader</code> to
418 <code>WebappClassLoader#parent</code> to prevent a memory leak. Note
419 that the keep-alive timer thread will stop on its own once the
420 keep-alives all expire however, on a busy system that might not happen
421 for some time. If not specified, the default value of
422 <code>true</code> will be used.</p>
423 </td></tr><tr><td align="left" valign="center"><code>clearReferencesStopThreads</code></td><td align="left" valign="center">
424 <p>If <code>true</code>, Tomcat attempts to terminate threads that have
425 been started by the web application. Stopping threads is performed via
426 the deprecated (for good reason) <code>Thread.stop()</code> method and
427 is likely to result in instability. As such, enabling this should be
428 viewed as an option of last resort in a development environment and is
429 not recommended in a production environment. If not specified, the
430 default value of <code>false</code> will be used.</p>
431 </td></tr><tr><td align="left" valign="center"><code>clearReferencesStopTimerThreads</code></td><td align="left" valign="center">
432 <p>If <code>true</code>, Tomcat attempts to terminate
433 <code>java.util.Timer</code> threads that have been started by the web
434 application. Unlike standard threads, timer threads can be stopped
435 safely although there may still be side-effects for the application. If
436 not specified, the default value of <code>false</code> will be used.</p>
437 </td></tr><tr><td align="left" valign="center"><code>clearReferencesThreadLocals</code></td><td align="left" valign="center">
438 <p>If <code>true</code>, Tomcat attempts to clear any ThreadLocal
439 objects that are instances of classes loaded by this class loader.
440 Failure to remove any such objects will result in a memory leak on web
441 application stop, undeploy or reload. If not specified, the default
442 value of <code>false</code> will be used since the clearing of the
443 ThreadLocal objects is not performed in a thread-safe manner.</p>
444 </td></tr><tr><td align="left" valign="center"><code>processTlds</code></td><td align="left" valign="center">
445 <p>Whether the context should process TLDs on startup. The default
446 is true. The false setting is intended for special cases
447 that know in advance TLDs are not part of the webapp.</p>
448 </td></tr><tr><td align="left" valign="center"><code>swallowOutput</code></td><td align="left" valign="center">
449 <p>If the value of this flag is <code>true</code>, the bytes output to
450 System.out and System.err by the web application will be redirected to
451 the web application logger. If not specified, the default value
452 of the flag is <code>false</code>.</p>
453 </td></tr><tr><td align="left" valign="center"><code>unloadDelay</code></td><td align="left" valign="center">
454 <p>Number of ms that the container will wait for servlets to unload.
455 If not specified, the default value is <code>2000</code> ms.</p>
456 </td></tr><tr><td align="left" valign="center"><code>unpackWAR</code></td><td align="left" valign="center">
457 <p>If true, Tomcat will unpack all compressed web applications before
458 running them.
459 If not specified, the default value is <code>true</code>.</p>
460 </td></tr><tr><td align="left" valign="center"><code>useNaming</code></td><td align="left" valign="center">
461 <p>Set to <code>true</code> (the default) to have Catalina enable a
462 JNDI <code>InitialContext</code> for this web application that is
463 compatible with Java2 Enterprise Edition (J2EE) platform
464 conventions.</p>
465 </td></tr><tr><td align="left" valign="center"><code>workDir</code></td><td align="left" valign="center">
466 <p>Pathname to a scratch directory to be provided by this Context
467 for temporary read-write use by servlets within the associated web
468 application. This directory will be made visible to servlets in the
469 web application by a servlet context attribute (of type
470 <code>java.io.File</code>) named
471 <code>javax.servlet.context.tempdir</code> as described in the
472 Servlet Specification. If not specified, a suitable directory
473 underneath <code>$CATALINA_BASE/work</code> will be provided.</p>
474 </td></tr></table>
475
476 </blockquote></td></tr></table>
477
478
479</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Nested Components"><!--()--></a><a name="Nested_Components"><strong>Nested Components</strong></a></font></td></tr><tr><td><blockquote>
480
481 <p>You can nest at most one instance of the following utility components
482 by nesting a corresponding element inside your <strong>Context</strong>
483 element:</p>
484 <ul>
485 <li><a href="loader.html"><strong>Loader</strong></a> -
486 Configure the web application class loader that will be used to load
487 servlet and bean classes for this web application. Normally, the
488 default configuration of the class loader will be sufficient.</li>
489 <li><a href="manager.html"><strong>Manager</strong></a> -
490 Configure the session manager that will be used to create, destroy,
491 and persist HTTP sessions for this web application. Normally, the
492 default configuration of the session manager will be sufficient.</li>
493 <li><a href="realm.html"><strong>Realm</strong></a> -
494 Configure a realm that will allow its
495 database of users, and their associated roles, to be utilized solely
496 for this particular web application. If not specified, this web
497 application will utilize the Realm associated with the owning
498 <a href="host.html">Host</a> or <a href="engine.html">Engine</a>.</li>
499 <li><a href="resources.html"><strong>Resources</strong></a> -
500 Configure the resource manager that will be used to access the static
501 resources associated with this web application. Normally, the
502 default configuration of the resource manager will be sufficient.</li>
503 <li><strong>WatchedResource</strong> - The auto deployer will monitor the
504 specified static resource of the web application for updates, and will
505 reload the web application if is is updated. The content of this element
506 must be a string.</li>
507 </ul>
508
509</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Special Features"><!--()--></a><a name="Special_Features"><strong>Special Features</strong></a></font></td></tr><tr><td><blockquote>
510
511
512 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Logging"><strong>Logging</strong></a></font></td></tr><tr><td><blockquote>
513
514 <p>A context is associated with the
515 <code>org.apache.catalina.core.ContainerBase.[enginename].[hostname].[path]</code>
516 log category. Note that the brackets are actually part of the name, don't omit them.</p>
517
518 </blockquote></td></tr></table>
519
520
521 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Access Logs"><!--()--></a><a name="Access_Logs"><strong>Access Logs</strong></a></font></td></tr><tr><td><blockquote>
522
523 <p>When you run a web server, one of the output files normally generated
524 is an <em>access log</em>, which generates one line of information for
525 each request processed by the server, in a standard format. Catalina
526 includes an optional <a href="valve.html">Valve</a> implementation that
527 can create access logs in the same standard format created by web servers,
528 or in any number of custom formats.</p>
529
530 <p>You can ask Catalina to create an access log for all requests
531 processed by an <a href="engine.html">Engine</a>,
532 <a href="host.html">Host</a>, or <a href="context.html">Context</a>
533 by nesting a <a href="valve.html">Valve</a> element like this:</p>
534
535<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
536&lt;Context&gt;
537 ...
538 &lt;Valve className="org.apache.catalina.valves.AccessLogValve"
539 prefix="localhost_access_log." suffix=".txt"
540 pattern="common"/&gt;
541 ...
542&lt;/Context&gt;
543</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
544
545 <p>See <a href="valve.html#Access Log Valve">Access Log Valve</a>
546 for more information on the configuration attributes that are
547 supported.</p>
548
549 </blockquote></td></tr></table>
550
551
552 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Automatic Context Configuration"><!--()--></a><a name="Automatic_Context_Configuration"><strong>Automatic Context Configuration</strong></a></font></td></tr><tr><td><blockquote>
553
554 <p>If you use the standard <strong>Context</strong> implementation,
555 the following configuration steps occur automatically when Catalina
556 is started, or whenever this web application is reloaded. No special
557 configuration is required to enable this feature.</p>
558
559 <ul>
560 <li>If you have not declared your own <a href="loader.html">Loader</a>
561 element, a standard web application class loader will be configured.
562 </li>
563 <li>If you have not declared your own <a href="manager.html">Manager</a>
564 element, a standard session manager will be configured.</li>
565 <li>If you have not declared your own <a href="resources.html">Resources</a>
566 element, a standard resources manager will be configured.</li>
567 <li>The web application properties listed in <code>conf/web.xml</code>
568 will be processed as defaults for this web application. This is used
569 to establish default mappings (such as mapping the <code>*.jsp</code>
570 extension to the corresponding JSP servlet), and other standard
571 features that apply to all web applications.</li>
572 <li>The web application properties listed in the
573 <code>/WEB-INF/web.xml</code> resource for this web application
574 will be processed (if this resource exists).</li>
575 <li>If your web application has specified security constraints that might
576 require user authentication, an appropriate Authenticator that
577 implements the login method you have selected will be configured.</li>
578 </ul>
579
580 </blockquote></td></tr></table>
581
582
583 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Context Parameters"><!--()--></a><a name="Context_Parameters"><strong>Context Parameters</strong></a></font></td></tr><tr><td><blockquote>
584
585 <p>You can configure named values that will be made visible to the
586 web application as servlet context initialization parameters by nesting
587 <code>&lt;Parameter&gt;</code> elements inside this element. For
588 example, you can create an initialization parameter like this:</p>
589<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
590&lt;Context&gt;
591 ...
592 &lt;Parameter name="companyName" value="My Company, Incorporated"
593 override="false"/&gt;
594 ...
595&lt;/Context&gt;
596</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
597
598 <p>This is equivalent to the inclusion of the following element in the
599 web application deployment descriptor (<code>/WEB-INF/web.xml</code>):
600 </p>
601<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
602&lt;context-param&gt;
603 &lt;param-name&gt;companyName&lt;/param-name&gt;
604 &lt;param-value&gt;My Company, Incorporated&lt;/param-value&gt;
605&lt;/context-param&gt;
606</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
607 <p>but does <em>not</em> require modification of the deployment descriptor
608 to customize this value.</p>
609
610 <p>The valid attributes for a <code>&lt;Parameter&gt;</code> element
611 are as follows:</p>
612
613 <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code>description</code></td><td align="left" valign="center">
614 <p>Optional, human-readable description of this context
615 initialization parameter.</p>
616 </td></tr><tr><td align="left" valign="center"><strong><code>name</code></strong></td><td align="left" valign="center">
617 <p>The name of the context initialization parameter to be created.</p>
618 </td></tr><tr><td align="left" valign="center"><code>override</code></td><td align="left" valign="center">
619 <p>Set this to <code>false</code> if you do <strong>not</strong> want
620 a <code>&lt;context-param&gt;</code> for the same parameter name,
621 found in the web application deployment descriptor, to override the
622 value specified here. By default, overrides are allowed.</p>
623 </td></tr><tr><td align="left" valign="center"><strong><code>value</code></strong></td><td align="left" valign="center">
624 <p>The parameter value that will be presented to the application
625 when requested by calling
626 <code>ServletContext.getInitParameter()</code>.</p>
627 </td></tr></table>
628
629 </blockquote></td></tr></table>
630
631
632 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Environment Entries"><!--()--></a><a name="Environment_Entries"><strong>Environment Entries</strong></a></font></td></tr><tr><td><blockquote>
633
634 <p>You can configure named values that will be made visible to the
635 web application as environment entry resources, by nesting
636 <code>&lt;Environment&gt;</code> entries inside this element. For
637 example, you can create an environment entry like this:</p>
638<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
639&lt;Context&gt;
640 ...
641 &lt;Environment name="maxExemptions" value="10"
642 type="java.lang.Integer" override="false"/&gt;
643 ...
644&lt;/Context&gt;
645</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
646
647 <p>This is equivalent to the inclusion of the following element in the
648 web application deployment descriptor (<code>/WEB-INF/web.xml</code>):
649 </p>
650<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
651&lt;env-entry&gt;
652 &lt;env-entry-name&gt;maxExemptions&lt;/env-entry-name&gt;
653 &lt;env-entry-value&gt;10&lt;/env-entry-value&gt;
654 &lt;env-entry-type&gt;java.lang.Integer&lt;/env-entry-type&gt;
655&lt;/env-entry&gt;
656</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
657 <p>but does <em>not</em> require modification of the deployment descriptor
658 to customize this value.</p>
659
660 <p>The valid attributes for an <code>&lt;Environment&gt;</code> element
661 are as follows:</p>
662
663 <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code>description</code></td><td align="left" valign="center">
664 <p>Optional, human-readable description of this environment entry.</p>
665 </td></tr><tr><td align="left" valign="center"><strong><code>name</code></strong></td><td align="left" valign="center">
666 <p>The name of the environment entry to be created, relative to the
667 <code>java:comp/env</code> context.</p>
668 </td></tr><tr><td align="left" valign="center"><code>override</code></td><td align="left" valign="center">
669 <p>Set this to <code>false</code> if you do <strong>not</strong> want
670 an <code>&lt;env-entry&gt;</code> for the same environment entry name,
671 found in the web application deployment descriptor, to override the
672 value specified here. By default, overrides are allowed.</p>
673 </td></tr><tr><td align="left" valign="center"><strong><code>type</code></strong></td><td align="left" valign="center">
674 <p>The fully qualified Java class name expected by the web application
675 for this environment entry. Must be one of the legal values for
676 <code>&lt;env-entry-type&gt;</code> in the web application deployment
677 descriptor: <code>java.lang.Boolean</code>,
678 <code>java.lang.Byte</code>, <code>java.lang.Character</code>,
679 <code>java.lang.Double</code>, <code>java.lang.Float</code>,
680 <code>java.lang.Integer</code>, <code>java.lang.Long</code>,
681 <code>java.lang.Short</code>, or <code>java.lang.String</code>.</p>
682 </td></tr><tr><td align="left" valign="center"><strong><code>value</code></strong></td><td align="left" valign="center">
683 <p>The parameter value that will be presented to the application
684 when requested from the JNDI context. This value must be convertable
685 to the Java type defined by the <code>type</code> attribute.</p>
686 </td></tr></table>
687
688 </blockquote></td></tr></table>
689
690
691 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Lifecycle Listeners"><!--()--></a><a name="Lifecycle_Listeners"><strong>Lifecycle Listeners</strong></a></font></td></tr><tr><td><blockquote>
692
693 <p>If you have implemented a Java object that needs to know when this
694 <strong>Context</strong> is started or stopped, you can declare it by
695 nesting a <strong>Listener</strong> element inside this element. The
696 class name you specify must implement the
697 <code>org.apache.catalina.LifecycleListener</code> interface, and
698 the class must be packaged in a jar and placed in the
699 <code>$CATALINA_HOME/lib</code> directory.
700 It will be notified about the occurrence of the corresponding
701 lifecycle events. Configuration of such a listener looks like this:</p>
702
703<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
704&lt;Context&gt;
705 ...
706 &lt;Listener className="com.mycompany.mypackage.MyListener" ... &gt;
707 ...
708&lt;/Context&gt;
709</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
710
711 <p>Note that a Listener can have any number of additional properties
712 that may be configured from this element. Attribute names are matched
713 to corresponding JavaBean property names using the standard property
714 method naming patterns.</p>
715
716 </blockquote></td></tr></table>
717
718
719 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Request Filters"><!--()--></a><a name="Request_Filters"><strong>Request Filters</strong></a></font></td></tr><tr><td><blockquote>
720
721 <p>You can ask Catalina to check the IP address, or host name, on every
722 incoming request directed to the surrounding
723 <a href="engine.html">Engine</a>, <a href="host.html">Host</a>, or
724 <a href="context.html">Context</a> element. The remote address or name
725 will be checked against a configured list of "accept" and/or "deny"
726 filters, which are defined using <code>java.util.regex</code> Regular
727 Expression syntax. Requests that come from locations that are
728 not accepted will be rejected with an HTTP "Forbidden" error.
729 Example filter declarations:</p>
730
731<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
732&lt;Context&gt;
733 ...
734 &lt;Valve className="org.apache.catalina.valves.RemoteHostValve"
735 allow=".*\.mycompany\.com|www\.yourcompany\.com"/&gt;
736 &lt;Valve className="org.apache.catalina.valves.RemoteAddrValve"
737 deny="192\.168\.1\.\d+"/&gt;
738 ...
739&lt;/Context&gt;
740</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
741
742 <p>See <a href="valve.html#Remote Address Filter">Remote Address Filter</a>
743 and <a href="valve.html#Remote Host Filter">Remote Host Filter</a> for
744 more information about the configuration options that are supported.</p>
745
746 </blockquote></td></tr></table>
747
748
749 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Resource Definitions"><!--()--></a><a name="Resource_Definitions"><strong>Resource Definitions</strong></a></font></td></tr><tr><td><blockquote>
750
751 <p>You can declare the characteristics of the resource
752 to be returned for JNDI lookups of <code>&lt;resource-ref&gt;</code> and
753 <code>&lt;resource-env-ref&gt;</code> elements in the web application
754 deployment descriptor. You <strong>MUST</strong> also define
755 the needed resource parameters as attributes of the <code>Resource</code>
756 element, to configure the object factory to be used (if not known to Tomcat
757 already), and the properties used to configure that object factory.</p>
758
759 <p>For example, you can create a resource definition like this:</p>
760<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
761&lt;Context&gt;
762 ...
763 &lt;Resource name="jdbc/EmployeeDB" auth="Container"
764 type="javax.sql.DataSource"
765 description="Employees Database for HR Applications"/&gt;
766 ...
767&lt;/Context&gt;
768</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
769
770 <p>This is equivalent to the inclusion of the following element in the
771 web application deployment descriptor (<code>/WEB-INF/web.xml</code>):</p>
772<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
773&lt;resource-ref&gt;
774 &lt;description&gt;Employees Database for HR Applications&lt;/description&gt;
775 &lt;res-ref-name&gt;jdbc/EmployeeDB&lt;/res-ref-name&gt;
776 &lt;res-ref-type&gt;javax.sql.DataSource&lt;/res-ref-type&gt;
777 &lt;res-auth&gt;Container&lt;/res-auth&gt;
778&lt;/resource-ref&gt;
779</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
780
781 <p>but does <em>not</em> require modification of the deployment
782 descriptor to customize this value.</p>
783
784 <p>The valid attributes for a <code>&lt;Resource&gt;</code> element
785 are as follows:</p>
786
787 <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code>auth</code></td><td align="left" valign="center">
788 <p>Specify whether the web Application code signs on to the
789 corresponding resource manager programatically, or whether the
790 Container will sign on to the resource manager on behalf of the
791 application. The value of this attribute must be
792 <code>Application</code> or <code>Container</code>. This
793 attribute is <strong>required</strong> if the web application
794 will use a <code>&lt;resource-ref&gt;</code> element in the web
795 application deployment descriptor, but is optional if the
796 application uses a <code>&lt;resource-env-ref&gt;</code> instead.</p>
797 </td></tr><tr><td align="left" valign="center"><code>description</code></td><td align="left" valign="center">
798 <p>Optional, human-readable description of this resource.</p>
799 </td></tr><tr><td align="left" valign="center"><strong><code>name</code></strong></td><td align="left" valign="center">
800 <p>The name of the resource to be created, relative to the
801 <code>java:comp/env</code> context.</p>
802 </td></tr><tr><td align="left" valign="center"><code>scope</code></td><td align="left" valign="center">
803 <p>Specify whether connections obtained through this resource
804 manager can be shared. The value of this attribute must be
805 <code>Shareable</code> or <code>Unshareable</code>. By default,
806 connections are assumed to be shareable.</p>
807 </td></tr><tr><td align="left" valign="center"><strong><code>type</code></strong></td><td align="left" valign="center">
808 <p>The fully qualified Java class name expected by the web
809 application when it performs a lookup for this resource.</p>
810 </td></tr></table>
811
812
813 </blockquote></td></tr></table>
814
815
816 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Resource Links"><!--()--></a><a name="Resource_Links"><strong>Resource Links</strong></a></font></td></tr><tr><td><blockquote>
817
818 <p>This element is used to create a link to a global JNDI resource. Doing
819 a JNDI lookup on the link name will then return the linked global
820 resource.</p>
821
822 <p>For example, you can create a resource link like this:</p>
823<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
824&lt;Context&gt;
825 ...
826 &lt;ResourceLink name="linkToGlobalResource"
827 global="simpleValue"
828 type="java.lang.Integer"
829 ...
830&lt;/Context&gt;
831</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
832
833 <p>The valid attributes for a <code>&lt;ResourceLink&gt;</code> element
834 are as follows:</p>
835
836 <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><strong><code>global</code></strong></td><td align="left" valign="center">
837 <p>The name of the linked global resource in the
838 global JNDI context.</p>
839 </td></tr><tr><td align="left" valign="center"><strong><code>name</code></strong></td><td align="left" valign="center">
840 <p>The name of the resource link to be created, relative to the
841 <code>java:comp/env</code> context.</p>
842 </td></tr><tr><td align="left" valign="center"><strong><code>type</code></strong></td><td align="left" valign="center">
843 <p>The fully qualified Java class name expected by the web
844 application when it performs a lookup for this resource link.</p>
845 </td></tr><tr><td align="left" valign="center"><code>factory</code></td><td align="left" valign="center">
846 <p>The fully qualified Java class name for the class creating these objects.
847 This class should implement the <code>javax.naming.spi.ObjectFactory</code> interface.</p>
848 </td></tr></table>
849
850 <p>When the attribute <code>factory="org.apache.naming.factory.DataSourceLinkFactory"</code> the resource link can be used with
851 two additional attributes to allow a shared data source to be used with different credentials.
852 When these two additional attributes are used in combination with the <code>javax.sql.DataSource</code>
853 type, different contexts can share a global data source with different credentials.
854 Under the hood, what happens is that a call to <a href="http://docs.oracle.com/javase/6/docs/api/javax/sql/DataSource.html#getConnection()"><code>getConnection()</code></a>
855 is simply translated to a call <a href="http://docs.oracle.com/javase/6/docs/api/javax/sql/DataSource.html#getConnection(java.lang.String,%20java.lang.String)">
856 <code>getConnection(username, password)</code></a> on the global data source. This is an easy way to get code to be transparent to what schemas are being used,
857 yet be able to control connections (or pools) in the global configuration.
858 </p>
859 <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code>username</code></td><td align="left" valign="center">
860 <p><code>username</code> value for the <code>getConnection(username, password)</code>
861 call on the linked global DataSource.
862 </p>
863 </td></tr><tr><td align="left" valign="center"><code>password</code></td><td align="left" valign="center">
864 <p><code>password</code> value for the <code>getConnection(username, password)</code>
865 call on the linked global DataSource.
866 </p>
867 </td></tr></table>
868 <p>Shared Data Source Example:</p>
869 <p><strong>Warning:</strong> This feature works only if the global DataSource
870supports <code>getConnection(username, password)</code> method.
871<a href="http://commons.apache.org/dbcp/">Apache Commons DBCP</a> pool that
872Tomcat uses by default does not support it. See its Javadoc for
873<code>BasicDataSource</code> class.
874<a href="http://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html">Apache Tomcat JDBC pool</a>
875(included with Tomcat 7 and later) does support it,
876but by default this support is disabled and can be enabled by
877<code>alternateUsernameAllowed</code> attribute. See its documentation
878for details. The example below uses Apache Tomcat JDBC pool.</p>
879<div align="left"><table cellspacing="4" cellpadding="0" border="0"><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#ffffff" height="1"><pre>
880&lt;GlobalNamingResources&gt;
881 ...
882 &lt;Resource name="sharedDataSource"
883 global="sharedDataSource"
884 type="javax.sql.DataSource"
885 factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
886 alternateUsernameAllowed="true"
887 username="bar"
888 password="barpass"
889 ...
890 ...
891&lt;/GlobalNamingResources&gt;
892
893&lt;Context path="/foo"...&gt;
894 ...
895 &lt;ResourceLink
896 name="appDataSource"
897 global="sharedDataSource"
898 type="javax.sql.DataSource"
899 factory="org.apache.naming.factory.DataSourceLinkFactory"
900 username="foo"
901 password="foopass"
902 ...
903&lt;/Context&gt;
904&lt;Context path="/bar"...&gt;
905 ...
906 &lt;ResourceLink
907 name="appDataSource"
908 global="sharedDataSource"
909 type="javax.sql.DataSource"
910 ...
911&lt;/Context&gt;
912</pre></td><td bgcolor="#023264" width="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr><tr><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td><td bgcolor="#023264" width="1" height="1"><img src="../images/void.gif" alt="" width="1" height="1" vspace="0" hspace="0" border="0"></td></tr></table></div>
913 <p>When a request for <code>getConnection()</code> is made in the <code>/foo</code> context, the request is translated into
914 <code>getConnection("foo","foopass")</code>, while a request in the <code>/bar</code> gets passed straight through.</p>
915 </blockquote></td></tr></table>
916
917 <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Transaction"><strong>Transaction</strong></a></font></td></tr><tr><td><blockquote>
918
919 <p>You can declare the characteristics of the UserTransaction
920 to be returned for JNDI lookup for <code>java:comp/UserTransaction</code>.
921 You <strong>MUST</strong> define an object factory class to instantiate
922 this object as well as the needed resource parameters as attributes of the
923 <code>Transaction</code>
924 element, and the properties used to configure that object factory.</p>
925
926 <p>The valid attributes for the <code>&lt;Transaction&gt;</code> element
927 are as follows:</p>
928
929 <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><strong><code>factory</code></strong></td><td align="left" valign="center">
930 <p>The class name for the JNDI object factory.</p>
931 </td></tr></table>
932
933 </blockquote></td></tr></table>
934
935</blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr noshade="noshade" size="1"></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font color="#525D76" size="-1"><em>
936 Copyright &copy; 1999-2014, Apache Software Foundation
937 </em></font></div></td></tr></table></body></html>