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		2	<html lang="en"><head><META http-equiv="Content-Type" content="text/html; charset=UTF-8"><link href="../images/docs-stylesheet.css" rel="stylesheet" type="text/css"><title>Apache Tomcat 9 Configuration Reference (9.0.112) - The Context Container</title></head><body><div id="wrapper"><header><div id="header"><div><div><div class="logo noPrint"><a href="https://tomcat.apache.org/"><img alt="Tomcat Home" src="../images/tomcat.png"></a></div><div style="height: 1px;"></div><div class="asfLogo noPrint"><a href="https://www.apache.org/" target="_blank"><img src="../images/asf-logo.svg" alt="The Apache Software Foundation" style="width: 266px; height: 83px;"></a></div><h1>Apache Tomcat 9 Configuration Reference</h1><div class="versionInfo">
		3	Version 9.0.112,
		4	<time datetime="2025-11-06">Nov 6 2025</time></div><div style="height: 1px;"></div><div style="clear: left;"></div></div></div></div></header><div id="middle"><div><div id="mainLeft" class="noprint"><div><nav><div><h2>Links</h2><ul><li><a href="../index.html">Docs Home</a></li><li><a href="index.html">Config Ref. Home</a></li><li><a href="https://cwiki.apache.org/confluence/display/TOMCAT/FAQ">FAQ</a></li><li><a href="#comments_section">User Comments</a></li></ul></div><div><h2>Top Level Elements</h2><ul><li><a href="server.html">Server</a></li><li><a href="service.html">Service</a></li></ul></div><div><h2>Executors</h2><ul><li><a href="executor.html">Executor</a></li></ul></div><div><h2>Connectors</h2><ul><li><a href="http.html">HTTP/1.1</a></li><li><a href="http2.html">HTTP/2</a></li><li><a href="ajp.html">AJP</a></li></ul></div><div><h2>Containers</h2><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></div><div><h2>Nested Components</h2><ul><li><a href="cookie-processor.html">CookieProcessor</a></li><li><a href="credentialhandler.html">CredentialHandler</a></li><li><a href="globalresources.html">Global Resources</a></li><li><a href="jar-scanner.html">JarScanner</a></li><li><a href="jar-scan-filter.html">JarScanFilter</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="sessionidgenerator.html">SessionIdGenerator</a></li><li><a href="valve.html">Valve</a></li></ul></div><div><h2>Cluster Elements</h2><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></div><div><h2>web.xml</h2><ul><li><a href="filter.html">Filter</a></li></ul></div><div><h2>Other</h2><ul><li><a href="runtime-attributes.html">Runtime attributes</a></li><li><a href="systemprops.html">System properties</a></li><li><a href="jaspic.html">JASPIC</a></li></ul></div></nav></div></div><div id="mainRight"><div id="content"><h2>The Context Container</h2><h3 id="Table_of_Contents">Table of Contents</h3><div class="text">
		5	<ul><li><a href="#Introduction">Introduction</a><ol><li><a href="#Parallel_deployment">Parallel deployment</a></li><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>
		6	</div><h3 id="Introduction">Introduction</h3><div class="text">
		7
		8	<p><em>
		9	The description below uses the variable name $CATALINA_BASE to refer the
		10	base directory against which most relative paths are resolved. If you have
		11	not configured Tomcat for multiple instances by setting a CATALINA_BASE
		12	directory, then $CATALINA_BASE will be set to the value of $CATALINA_HOME,
		13	the directory into which you have installed Tomcat.
		14	</em></p>
		15
		16	<p>The <strong>Context</strong> element represents a <em>web
		17	application</em>, which is run within a particular virtual host.
		18	Each web application is based on a <em>Web Application Archive</em>
		19	(WAR) file, or a corresponding directory containing the corresponding
		20	unpacked contents, as described in the Servlet Specification (version
		21	2.2 or later). For more information about web application archives,
		22	you can download the
		23	<a href="https://cwiki.apache.org/confluence/display/TOMCAT/Specifications">Servlet
		24	Specification</a>, and review the Tomcat
		25	<a href="../appdev/index.html">Application Developer's Guide</a>.</p>
		26
		27	<p>The web application used to process each HTTP request is selected
		28	by Catalina based on matching the longest possible prefix of the
		29	Request URI against the <em>context path</em> of each defined Context.
		30	Once selected, that Context will select an appropriate servlet to
		31	process the incoming request, according to the servlet mappings defined
		32	by the web application deployment.</p>
		33
		34	<p>You may define as many <strong>Context</strong> elements as you
		35	wish. Each such Context MUST have a unique context name within a virtual
		36	host. The context path does not need to be unique (see <em>parallel
		37	deployment</em> below). In addition, a Context must be present with a
		38	context path equal to
		39	a zero-length string. This Context becomes the <em>default</em>
		40	web application for this virtual host, and is used to process all
		41	requests that do not match any other Context's context path.</p>
		42
		43	<div class="subsection"><h4 id="Parallel_deployment">Parallel deployment</h4><div class="text">
		44	<p><b>You may deploy multiple versions of a web application with the same
		45	context path at the same time.</b> The rules used to match requests to a
		46	context version are as follows:
		47	</p>
		48	<ul>
		49	<li>If no session information is present in the request, use the latest
		50	version.</li>
		51	<li>If session information is present in the request, check the session
		52	manager of each version for a matching session and if one is found, use that
		53	version.</li>
		54	<li>If session information is present in the request but no matching session
		55	can be found, use the latest version.</li>
		56	</ul>
		57	<p>The <a href="host.html">Host</a> may be configured (via the
		58	<code>undeployOldVersions</code>) to remove old versions deployed in this way
		59	once they are no longer in use.</p>
		60	</div></div>
		61
		62	<div class="subsection"><h4 id="Naming">Naming</h4><div class="text">
		63	<p>When <code>autoDeploy</code> or <code>deployOnStartup</code> operations
		64	are performed by a Host, the name and context path of the web application are
		65	derived from the name(s) of the file(s) that define(s) the web application.
		66	Consequently, the context path <strong>may not</strong> be defined in a
		67	<code>META-INF/context.xml</code> embedded in the application and there is a
		68	close relationship between the <em>context name</em>, <em>context path</em>,
		69	<em>context version</em> and the <em>base file name</em> (the name minus any
		70	<code>.war</code> or <code>.xml</code> extension) of the file.</p>
		71
		72	<p>If no version is specified then the <em>context name</em> is always the
		73	same as the <em>context path</em>. If the <em>context path</em> is the empty
		74	string then the <em>base name</em> will be ROOT (always in upper case)
		75	otherwise the <em>base name</em> will be the <em>context path</em> with the
		76	leading '/' removed and any remaining '/' characters replaced with '#'.</p>
		77
		78	<p>If a version is specified then the <em>context path</em> remains unchanged
		79	and both the <em>context name</em> and the <em>base name</em> have the string
		80	'##' appended to them followed by the version identifier.</p>
		81
		82	<p>Some examples of these naming conventions are given below.</p>
		83
		84	<table class="detail-table">
		85	<tr>
		86	<th>Context Path</th>
		87	<th>Context Version</th>
		88	<th>Context Name</th>
		89	<th>Base File Name</th>
		90	<th>Example File Names (.xml, .war & directory)</th>
		91	</tr>
		92	<tr>
		93	<td>/foo</td>
		94	<td><i>None</i></td>
		95	<td>/foo</td>
		96	<td>foo</td>
		97	<td>foo.xml, foo.war, foo</td>
		98	</tr>
		99	<tr>
		100	<td>/foo/bar</td>
		101	<td><i>None</i></td>
		102	<td>/foo/bar</td>
		103	<td>foo#bar</td>
		104	<td>foo#bar.xml, foo#bar.war, foo#bar</td>
		105	</tr>
		106	<tr>
		107	<td><i>Empty String</i></td>
		108	<td><i>None</i></td>
		109	<td><i>Empty String</i></td>
		110	<td>ROOT</td>
		111	<td>ROOT.xml, ROOT.war, ROOT</td>
		112	</tr>
		113	<tr>
		114	<td>/foo</td>
		115	<td>42</td>
		116	<td>/foo##42</td>
		117	<td>foo##42</td>
		118	<td>foo##42.xml, foo##42.war, foo##42</td>
		119	</tr>
		120	<tr>
		121	<td>/foo/bar</td>
		122	<td>42</td>
		123	<td>/foo/bar##42</td>
		124	<td>foo#bar##42</td>
		125	<td>foo#bar##42.xml, foo#bar##42.war, foo#bar##42</td>
		126	</tr>
		127	<tr>
		128	<td><i>Empty String</i></td>
		129	<td>42</td>
		130	<td>##42</td>
		131	<td>ROOT##42</td>
		132	<td>ROOT##42.xml, ROOT##42.war, ROOT##42</td>
		133	</tr>
		134	</table>
		135
		136	<p>The version component is treated as a <code>String</code> both for
		137	performance reasons and to allow flexibility in versioning schemes. String
		138	comparisons are used to determine version order. If version is not specified,
		139	it is treated as the empty string.
		140	Therefore,
		141	<code>foo.war</code> will be treated as an earlier version than
		142	<code>foo##11.war</code> and
		143	<code>foo##11.war</code> will be treated as an earlier version than
		144	<code>foo##2.war</code>. If using a purely numerical versioning scheme it is
		145	recommended that zero padding is used so that <code>foo##002.war</code> is
		146	treated as an earlier version than <code>foo##011.war</code>.
		147	</p>
		148	<p>To get the current webapp version number in a servlet you should use
		149	<code>org.apache.catalina.webappVersion</code>
		150	<a href="runtime-attributes.html">attribute</a>, like this:
		151	<code>String webappVersion =
		152	(String)request.getServletContext().getAttribute("org.apache.catalina.webappVersion");
		153	</code>
		154	</p>
		155	<p>If you want to deploy a WAR file or a directory using a context path that
		156	is not related to the base file name then one of the following options must
		157	be used to prevent double-deployment:
		158	</p>
		159	<ul>
		160	<li>Disable autoDeploy and deployOnStartup and define all
		161	<strong>Context</strong>s in server.xml</li>
		162	<li>Locate the WAR and/or directory outside of the Host's
		163	<code>appBase</code> and use a context.xml file with a
		164	<code>docBase</code> attribute to define it.</li>
		165	</ul>
		166	</div></div>
		167
		168	<div class="subsection"><h4 id="Defining_a_context">Defining a context</h4><div class="text">
		169	<p><b>It is NOT recommended to place <Context> elements directly in the
		170	server.xml file.</b> This is because it makes modifying the
		171	<strong>Context</strong> configuration more invasive since the main
		172	<code>conf/server.xml</code> file cannot be reloaded without restarting
		173	Tomcat. Default <strong>Context</strong> elements (see below) will also
		174	<strong>overwrite</strong> the configuration of any <Context> elements
		175	placed directly in server.xml. To prevent this, the <code>override</code>
		176	attribute of the <Context> element defined in server.xml should be set
		177	to <code>true</code>.</p>
		178
		179	<p>Individual <strong>Context</strong> elements may be explicitly defined:
		180	</p>
		181	<ul>
		182	<li>In an individual file at <code>/META-INF/context.xml</code> inside the
		183	application files. Optionally (based on the Host's copyXML attribute)
		184	this may be copied to
		185	<code>$CATALINA_BASE/conf/[enginename]/[hostname]/</code> and renamed to
		186	application's base file name plus a ".xml" extension.</li>
		187	<li>In individual files (with a ".xml" extension) in the
		188	<code>$CATALINA_BASE/conf/[enginename]/[hostname]/</code> directory.
		189	The context path and version will be derived from the base name of the file
		190	(the file name less the .xml extension). This file will always take precedence
		191	over any context.xml file packaged in the web application's META-INF
		192	directory.</li>
		193	<li>Inside a <a href="host.html">Host</a> element in the main
		194	<code>conf/server.xml</code>.</li>
		195	</ul>
		196
		197	<p>Default <strong>Context</strong> elements may be defined that apply to
		198	multiple web applications. Configuration for an individual web application
		199	will override anything configured in one of these defaults. Any nested
		200	elements, e.g. <Resource> elements, that are defined in a default
		201	<strong>Context</strong> will be created once for each
		202	<strong>Context</strong> to which the default applies. They will <b>not</b> be
		203	shared between <strong>Context</strong> elements.
		204	</p>
		205	<ul>
		206	<li>In the <code>$CATALINA_BASE/conf/context.xml</code> file:
		207	the Context element information will be loaded by all web applications.</li>
		208	<li>In the
		209	<code>$CATALINA_BASE/conf/[enginename]/[hostname]/context.xml.default</code>
		210	file: the Context element information will be loaded by all web applications
		211	of that host.</li>
		212	</ul>
		213
		214	<p>With the exception of server.xml, files that define <strong>Context
		215	</strong> elements may only define a single <strong>Context</strong> element.
		216	</p>
		217
		218	<p>In addition to explicitly specified Context elements, there are
		219	several techniques by which Context elements can be created automatically
		220	for you. See <a href="host.html#Automatic_Application_Deployment">
		221	Automatic Application Deployment</a> and
		222	<a href="host.html#User_Web_Applications">User Web Applications</a>
		223	for more information.</p>
		224
		225	<p>To define multiple contexts that use a single WAR file or directory,
		226	use one of the options described in the <a href="#Naming">Naming</a>
		227	section above for creating a <strong>Context</strong> that has a path
		228	that is not related to the base file name.</p>
		229	</div></div>
		230	</div><h3 id="Attributes">Attributes</h3><div class="text">
		231
		232	<div class="subsection"><h4 id="Common_Attributes">Common Attributes</h4><div class="text">
		233
		234	<p>All implementations of <strong>Context</strong>
		235	support the following attributes:</p>
		236
		237	<table class="defaultTable"><tr><th style="width: 15%;">
		238	Attribute
		239	</th><th style="width: 85%;">
		240	Description
		241	</th></tr><tr id="Attributes_Common Attributes_allowCasualMultipartParsing"><td><code class="attributeName">allowCasualMultipartParsing</code></td><td>
		242	<p>Set to <code>true</code> if Tomcat should automatically parse
		243	multipart/form-data request bodies when HttpServletRequest.getPart*
		244	or HttpServletRequest.getParameter* is called, even when the
		245	target servlet isn't marked with the @MultipartConfig annotation
		246	(See Servlet Specification 3.0, Section 3.2 for details).
		247	Note that any setting other than <code>false</code> causes Tomcat
		248	to behave in a way that is not technically spec-compliant.
		249	The default is <code>false</code>.</p>
		250	</td></tr><tr id="Attributes_Common Attributes_allowMultipleLeadingForwardSlashInPath"><td><code class="attributeName">allowMultipleLeadingForwardSlashInPath</code></td><td>
		251	<p>Tomcat normalises sequences of multiple <code>/</code> characters in
		252	a URI to a single <code>/</code>. This is for consistency with the
		253	behaviour of file systems as URIs are often translated to file system
		254	paths. As a result, the return value of
		255	<code>HttpServletRequest#getContextPath()</code> is expected to start
		256	with multiple <code>/</code> characters for some URIs. This will cause
		257	problems if this value is used directly with
		258	<code>HttpServletResponse#sendRedirect()</code> as redirect paths that
		259	start with <code>//</code> are treated as protocol relative redirects.
		260	To avoid potential issues, Tomcat will collapse multiple leading
		261	<code>/</code> characters at the start of the return value for
		262	<code>HttpServletRequest#getContextPath()</code> to a single
		263	<code>/</code>. This attribute has a default value of <code>false</code>
		264	which enables the collapsing of multiple <code>/</code> characters. To
		265	disable this behaviour, set this attribute to <code>true</code>.</p>
		266	</td></tr><tr id="Attributes_Common Attributes_altDDName"><td><code class="attributeName">altDDName</code></td><td>
		267	<p>The absolute path to the alternative deployment descriptor for this
		268	context. This overrides the default deployment descriptor located at
		269	<code>/WEB-INF/web.xml</code>.</p>
		270	</td></tr><tr id="Attributes_Common Attributes_backgroundProcessorDelay"><td><code class="attributeName">backgroundProcessorDelay</code></td><td>
		271	<p>This value represents the delay in seconds between the
		272	invocation of the backgroundProcess method on this context and
		273	its child containers, including all wrappers.
		274	Child containers will not be invoked if their delay value is not
		275	negative (which would mean they are using their own processing
		276	thread). Setting this to a positive value will cause
		277	a thread to be spawn. After waiting the specified amount of time,
		278	the thread will invoke the backgroundProcess method on this host
		279	and all its child containers. A context will use background
		280	processing to perform session expiration and class monitoring for
		281	reloading. If not specified, the default value for this attribute is
		282	-1, which means the context will rely on the background processing
		283	thread of its parent host.</p>
		284	</td></tr><tr id="Attributes_Common Attributes_className"><td><code class="attributeName">className</code></td><td>
		285	<p>Java class name of the implementation to use. This class must
		286	implement the <code>org.apache.catalina.Context</code> interface.
		287	If not specified, the standard value (defined below) will be used.</p>
		288	</td></tr><tr id="Attributes_Common Attributes_containerSciFilter"><td><code class="attributeName">containerSciFilter</code></td><td>
		289	<p>The regular expression that specifies which container provided SCIs
		290	should be filtered out and not used for this context. Matching uses
		291	<code>java.util.regex.Matcher.find()</code> so the regular expression
		292	only has to match a sub-string of the fully qualified class name of the
		293	container provided SCI for it to be filtered out. If not specified,
		294	no filtering will be applied.</p>
		295	</td></tr><tr id="Attributes_Common Attributes_cookies"><td><code class="attributeName">cookies</code></td><td>
		296	<p>Set to <code>true</code> if you want cookies to be used for
		297	session identifier communication if supported by the client (this
		298	is the default). Set to <code>false</code> if you want to disable
		299	the use of cookies for session identifier communication, and rely
		300	only on URL rewriting by the application.</p>
		301	</td></tr><tr id="Attributes_Common Attributes_createUploadTargets"><td><code class="attributeName">createUploadTargets</code></td><td>
		302	<p>Set to <code>true</code> if Tomcat should attempt to create the
		303	temporary upload location specified in the <code>MultipartConfig</code>
		304	for a Servlet if the location does not already exist. If not specified,
		305	the default value of <code>false</code> will be used.</p>
		306	</td></tr><tr id="Attributes_Common Attributes_crossContext"><td><code class="attributeName">crossContext</code></td><td>
		307	<p>Set to <code>true</code> if you want calls within this application
		308	to <code>ServletContext.getContext()</code> to successfully return a
		309	request dispatcher for other web applications running on this virtual
		310	host. Set to <code>false</code> (the default) in security
		311	conscious environments, to make <code>getContext()</code> always
		312	return <code>null</code>.</p>
		313	</td></tr><tr id="Attributes_Common Attributes_dispatchersUseEncodedPaths"><td><code class="attributeName">dispatchersUseEncodedPaths</code></td><td>
		314	<p>Controls whether paths used in calls to obtain a request dispatcher
		315	ares expected to be encoded. This affects both how Tomcat handles calls
		316	to obtain a request dispatcher as well as how Tomcat generates paths
		317	used to obtain request dispatchers internally. If not specified, the
		318	default value of <code>true</code> is used. When encoding/decoding paths
		319	for a request dispatcher, UTF-8 is always used.</p>
		320	</td></tr><tr id="Attributes_Common Attributes_docBase"><td><strong><code class="attributeName">docBase</code></strong></td><td>
		321	<p>The <em>Document Base</em> (also known as the <em>Context
		322	Root</em>) directory for this web application, or the pathname
		323	to the web application archive file (if this web application is
		324	being executed directly from the WAR file). You may specify
		325	an absolute pathname for this directory or WAR file, or a pathname
		326	that is relative to the <code>appBase</code> directory of the
		327	owning <a href="host.html">Host</a>.</p>
		328	<p>The value of this field must not be set unless the Context element is
		329	defined in server.xml or the <code>docBase</code> is not located under
		330	the <a href="host.html">Host</a>'s <code>appBase</code>.</p>
		331	<p>If a symbolic link is used for <code>docBase</code> then changes to
		332	the symbolic link will only be effective after a Tomcat restart or
		333	by undeploying and redeploying the context. A context reload is not
		334	sufficient.</p>
		335	</td></tr><tr id="Attributes_Common Attributes_encodedReverseSolidusHandling"><td><code class="attributeName">encodedReverseSolidusHandling</code></td><td>
		336	<p>When set to <code>reject</code>, an attempt to obtain a
		337	<code>RequestDispatcher</code> for a path containing a <code>%5c</code>
		338	sequence will trigger an <code>IllegalArgumentException</code>. When set
		339	to <code>decode</code>, any <code>%5c</code> sequence in the path used
		340	to obtain a <code>RequestDispatcher</code> will have that sequence
		341	decoded to <code>\</code> (and then normalized to <code>/</code>) before
		342	the <code>RequestDispatcher</code> is created. When set to
		343	<code>passthrough</code>, any <code>%5c</code> sequence in the path used
		344	to obtain a <code>RequestDispatcher</code> will remain unchanged.</p>
		345	<p>If <code>passthrough</code> is used then it is the application's
		346	responsibility to perform any further <code>%nn</code> decoding required.
		347	Any <code>%25</code> sequences (encoded <code>%</code>) in the path will
		348	also be processed with the <code>%25</code> sequence unchanged
		349	to avoid potential corruption and/or decoding failure when the path is
		350	subsequently <code>%nn</code> decoded by the application.</p>
		351	<p>If not specified, the default value is <code>decode</code>.</p>
		352	</td></tr><tr id="Attributes_Common Attributes_encodedSolidusHandling"><td><code class="attributeName">encodedSolidusHandling</code></td><td>
		353	<p>When set to <code>reject</code>, an attempt to obtain a
		354	<code>RequestDispatcher</code> for a path containing a <code>%2f</code>
		355	sequence will trigger an <code>IllegalArgumentException</code>. When set
		356	to <code>decode</code>, any <code>%2f</code> sequence in the path used
		357	to obtain a <code>RequestDispatcher</code> will have that sequence
		358	decoded to <code>/</code> before the <code>RequestDispatcher</code> is
		359	created. When set to <code>passthrough</code>, any <code>%2f</code>
		360	sequence in the path used to obtain a <code>RequestDispatcher</code>
		361	will remain unchanged.</p>
		362	<p>If <code>passthrough</code> is used then it is the application's
		363	responsibility to perform any further <code>%nn</code> decoding required.
		364	Any <code>%25</code> sequences (encoded <code>%</code>) in the path will
		365	also be processed with the <code>%25</code> sequence unchanged
		366	to avoid potential corruption and/or decoding failure when the path is
		367	subsequently <code>%nn</code> decoded by the application.</p>
		368	<p>If not specified, the default value is <code>decode</code>. This
		369	default will change to <code>reject</code> (to align with the
		370	<strong>Connector</strong>) in Tomcat 12.</p>
		371	</td></tr><tr id="Attributes_Common Attributes_failCtxIfServletStartFails"><td><code class="attributeName">failCtxIfServletStartFails</code></td><td>
		372	<p>Set to <code>true</code> to have the context fail its startup if any
		373	servlet that has load-on-startup >=0 fails its own startup.</p>
		374	<p>If not specified, the attribute of the same name in the parent Host
		375	configuration is used if specified. Otherwise the default value of
		376	<code>false</code> is used.</p>
		377	</td></tr><tr id="Attributes_Common Attributes_fireRequestListenersOnForwards"><td><code class="attributeName">fireRequestListenersOnForwards</code></td><td>
		378	<p>Set to <code>true</code> to fire any configured
		379	ServletRequestListeners when Tomcat forwards a request. This is
		380	primarily of use to users of CDI frameworks that use
		381	ServletRequestListeners to configure the necessary environment for a
		382	request. If not specified, the default value of <code>false</code> is
		383	used.</p>
		384	</td></tr><tr id="Attributes_Common Attributes_logEffectiveWebXml"><td><code class="attributeName">logEffectiveWebXml</code></td><td>
		385	<p>Set to <code>true</code> if you want the effective web.xml used for a
		386	web application to be logged (at INFO level) when the application
		387	starts. The effective web.xml is the result of combining the
		388	application's web.xml with any defaults configured by Tomcat and any
		389	web-fragment.xml files and annotations discovered. If not specified, the
		390	default value of <code>false</code> is used.</p>
		391	</td></tr><tr id="Attributes_Common Attributes_mapperContextRootRedirectEnabled"><td><code class="attributeName">mapperContextRootRedirectEnabled</code></td><td>
		392	<p>If enabled, requests for a web application context root will be
		393	redirected (adding a trailing slash) if necessary by the Mapper rather
		394	than the default Servlet. This is more efficient but there are security
		395	side effects. First, the existence of a web application or a directory
		396	may be confirmed even though the user does not have access to that
		397	directory. Secondly, any Valves and/or Filters - including those
		398	providing security functionality - will not have an opportunity to
		399	process the request. If not specified, the default value of
		400	<code>true</code> is used.</p>
		401	</td></tr><tr id="Attributes_Common Attributes_mapperDirectoryRedirectEnabled"><td><code class="attributeName">mapperDirectoryRedirectEnabled</code></td><td>
		402	<p>If enabled, requests for a web application directory will be
		403	redirected (adding a trailing slash) if necessary by the Mapper rather
		404	than the default Servlet. This is more efficient but there are security
		405	side effects. First, the existence of a web application or a directory
		406	may be confirmed even though the user does not have access to that
		407	directory. Secondly, any Valves and/or Filters - including those
		408	providing security functionality - will not have an opportunity to
		409	process the request. If not specified, the default value of
		410	<code>false</code> is used.</p>
		411	</td></tr><tr id="Attributes_Common Attributes_override"><td><code class="attributeName">override</code></td><td>
		412	<p>Set to <code>true</code> to ignore any settings in both the global
		413	or <a href="host.html">Host</a> default contexts. By default, settings
		414	from a default context will be used but may be overridden by a setting
		415	the same attribute explicitly for the Context.</p>
		416	</td></tr><tr id="Attributes_Common Attributes_parallelAnnotationScanning"><td><code class="attributeName">parallelAnnotationScanning</code></td><td>
		417	<p>When set to <code>true</code> annotation scanning will be performed
		418	using the utility executor. It will allow processing scanning in
		419	parallel which may improve deployment type at the expense of higher
		420	server load. If not specified, the default of <code>false</code> is
		421	used.</p>
		422	</td></tr><tr id="Attributes_Common Attributes_path"><td><code class="attributeName">path</code></td><td>
		423	<p>The <em>context path</em> of this web application, which is
		424	matched against the beginning of each request URI to select the
		425	appropriate web application for processing. All of the context paths
		426	within a particular <a href="host.html">Host</a> must be unique.
		427	If you specify a context path of an empty string (""), you are
		428	defining the <em>default</em> web application for this Host, which
		429	will process all requests not assigned to other Contexts.</p>
		430	<p>This attribute must only be used when statically defining a Context
		431	in server.xml. In all other circumstances, the path will be inferred
		432	from the filenames used for either the .xml context file or the
		433	<code>docBase</code>.
		434	</p>
		435	<p>Even when statically defining a Context in server.xml, this attribute
		436	must not be set unless either the <code>docBase</code> is not located
		437	under the <a href="host.html">Host</a>'s <code>appBase</code> or
		438	both <code>deployOnStartup</code> and <code>autoDeploy</code> are
		439	<code>false</code>. If this rule is not followed, double deployment is
		440	likely to result.</p>
		441	</td></tr><tr id="Attributes_Common Attributes_preemptiveAuthentication"><td><code class="attributeName">preemptiveAuthentication</code></td><td>
		442	<p>When set to <code>true</code> and the user presents credentials for a
		443	resource that is not protected by a security constraint, if the
		444	authenticator supports preemptive authentication (the standard
		445	authenticators provided with Tomcat do) then the user' credentials
		446	will be processed. If not specified, the default of <code>false</code> is
		447	used.
		448	</p>
		449	</td></tr><tr id="Attributes_Common Attributes_privileged"><td><code class="attributeName">privileged</code></td><td>
		450	<p>Set to <code>true</code> to allow this context to use container
		451	servlets, like the manager servlet. Use of the <code>privileged</code>
		452	attribute will change the context's parent class loader to be the
		453	<em>Server</em> class loader rather than the <em>Shared</em> class
		454	loader. Note that in a default installation, the <em>Common</em> class
		455	loader is used for both the <em>Server</em> and the <em>Shared</em>
		456	class loaders.</p>
		457	</td></tr><tr id="Attributes_Common Attributes_reloadable"><td><code class="attributeName">reloadable</code></td><td>
		458	<p>Set to <code>true</code> if you want Catalina to monitor classes in
		459	<code>/WEB-INF/classes/</code> and <code>/WEB-INF/lib</code> for
		460	changes, and automatically reload the web application if a change
		461	is detected. This feature is very useful during application
		462	development, but it requires significant runtime overhead and is
		463	not recommended for use on deployed production applications. That's
		464	why the default setting for this attribute is <i>false</i>. You
		465	can use the <a href="../manager-howto.html">Manager</a> web
		466	application, however, to trigger reloads of deployed applications
		467	on demand.</p>
		468	</td></tr><tr id="Attributes_Common Attributes_resourceOnlyServlets"><td><code class="attributeName">resourceOnlyServlets</code></td><td>
		469	<p>Comma separated list of Servlet names (as used in
		470	<code>/WEB-INF/web.xml</code>) that expect a resource to be present.
		471	Ensures that welcome files associated with Servlets that expect a
		472	resource to be present (such as the JSP Servlet) are not used when there
		473	is no resource present. This prevents issues caused by the clarification
		474	of welcome file mapping in section 10.10 of the Servlet 3.0
		475	specification. If the
		476	<code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code>
		477	<a href="systemprops.html">system property</a> is set to
		478	<code>true</code>, the default value of this attribute will be the empty
		479	string, else the default value will be <code>jsp</code>.</p>
		480	</td></tr><tr id="Attributes_Common Attributes_sendRedirectBody"><td><code class="attributeName">sendRedirectBody</code></td><td>
		481	<p>If <code>true</code>, redirect responses will include a short
		482	response body that includes details of the redirect as recommended by
		483	RFC 2616. This is disabled by default since including a response body
		484	may cause problems for some application component such as compression
		485	filters.</p>
		486	</td></tr><tr id="Attributes_Common Attributes_sessionCookieDomain"><td><code class="attributeName">sessionCookieDomain</code></td><td>
		487	<p>The domain to be used for all session cookies created for this
		488	context. If set, this overrides any domain set by the web application.
		489	If not set, the value specified by the web application, if any, will be
		490	used.</p>
		491	</td></tr><tr id="Attributes_Common Attributes_sessionCookieName"><td><code class="attributeName">sessionCookieName</code></td><td>
		492	<p>The name to be used for all session cookies created for this
		493	context. If set, this overrides any name set by the web application.
		494	If not set, the value specified by the web application, if any, will be
		495	used, or the name <code>JSESSIONID</code> if the web application does
		496	not explicitly set one.</p>
		497	</td></tr><tr id="Attributes_Common Attributes_sessionCookiePath"><td><code class="attributeName">sessionCookiePath</code></td><td>
		498	<p>The path to be used for all session cookies created for this
		499	context. If set, this overrides any path set by the web application.
		500	If not set, the value specified by the web application will be used, or
		501	the context path used if the web application does not explicitly set
		502	one. To configure all web application to use an empty path (this can be
		503	useful for portlet specification implementations) set this attribute to
		504	<code>/</code> in the global <code>CATALINA_BASE/conf/context.xml</code>
		505	file.</p>
		506	<p>Note: Once one web application using
		507	<code>sessionCookiePath="/"</code> obtains a session, all
		508	subsequent sessions for any other web application in the same host also
		509	configured with <code>sessionCookiePath="/"</code> will always
		510	use the same session ID. This holds even if the session is invalidated
		511	and a new one created. This makes session fixation protection more
		512	difficult and requires custom, Tomcat specific code to change the
		513	session ID shared by the multiple applications.</p>
		514	</td></tr><tr id="Attributes_Common Attributes_sessionCookiePathUsesTrailingSlash"><td><code class="attributeName">sessionCookiePathUsesTrailingSlash</code></td><td>
		515	<p>Some browsers, such as Internet Explorer, Safari and Edge, will send
		516	a session cookie for a context with a path of <code>/foo</code> with a
		517	request to <code>/foobar</code> in violation of RFC6265. This could
		518	expose a session ID from an application deployed at <code>/foo</code> to
		519	an application deployed at <code>/foobar</code>. If the application
		520	deployed at <code>/foobar</code> is untrusted, this could create a
		521	security risk. However, it should be noted that RFC 6265, section 8.5
		522	makes clear that path alone should not be view as sufficient to prevent
		523	untrusted applications accessing cookies from other applications. To
		524	mitigate this risk, this attribute may be set to <code>true</code> and
		525	Tomcat will add a trailing slash to the path associated with the session
		526	cookie so, in the above example, the cookie path becomes /foo/. However,
		527	with a cookie path of /foo/, browsers will no longer send the cookie
		528	with a request to /foo. This should not be a problem unless there is a
		529	servlet mapped to /*. In this case this attribute will need to be set to
		530	<code>false</code> to disable this feature. The default value for this
		531	attribute is <code>false</code>.</p>
		532	</td></tr><tr id="Attributes_Common Attributes_swallowAbortedUploads"><td><code class="attributeName">swallowAbortedUploads</code></td><td>
		533	<p>Set to <code>false</code> if Tomcat should <b>not</b> read any
		534	additional request body data for aborted uploads and instead abort the
		535	client connection. This setting is used in the following situations:
		536	</p>
		537	<ul>
		538	<li>Tomcat is automatically processing the request body for parameters
		539	and size of the request body data converted to parameters is larger
		540	than the <code>maxPostSize</code> configured in the connector</li>
		541	<li>a size limit of a MultiPart upload is reached</li>
		542	<li>the servlet sets the response status to 413 (Request Entity Too
		543	Large) </li>
		544	</ul>
		545	<p>
		546	Not reading the additional data will free the request processing thread
		547	more quickly. Unfortunately most HTTP clients will not read the response
		548	if they cannot write the full request.</p>
		549	<p>The default is <code>true</code>, so additional data will be
		550	read.</p>
		551	<p>Note if an error occurs during the request processing that triggers
		552	a 5xx response, any unread request data will always be ignored and the
		553	client connection will be closed once the error response has been
		554	written.</p>
		555	</td></tr><tr id="Attributes_Common Attributes_swallowOutput"><td><code class="attributeName">swallowOutput</code></td><td>
		556	<p>If the value of this flag is <code>true</code>, the bytes output to
		557	System.out and System.err by the web application will be redirected to
		558	the web application logger. If not specified, the default value
		559	of the flag is <code>false</code>.</p>
		560	</td></tr><tr id="Attributes_Common Attributes_tldValidation"><td><code class="attributeName">tldValidation</code></td><td>
		561	<p>If the value of this flag is <code>true</code>, the TLD files
		562	will be XML validated on context startup. If the
		563	<code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code>
		564	<a href="systemprops.html">system property</a> is set to
		565	<code>true</code>, the default value of this attribute will be
		566	<code>true</code>, else the default value will be <code>false</code>.
		567	Setting this attribute to <code>true</code> will incur a performance
		568	penalty.</p>
		569	</td></tr><tr id="Attributes_Common Attributes_useBloomFilterForArchives"><td><code class="attributeName">useBloomFilterForArchives</code></td><td>
		570	<p>DEPRECATED: If this is <code>true</code> then a bloom filter will be
		571	used to speed up archive lookups. This can be beneficial to the deployment
		572	speed to web applications that contain very large amount of JARs.</p>
		573	<p>If not specified, the default value of <code>false</code> will be
		574	used.</p>
		575	<p>This value can be overridden by archiveIndexStrategy in
		576	<a href="resources.html">Resources</a></p>
		577	</td></tr><tr id="Attributes_Common Attributes_useHttpOnly"><td><code class="attributeName">useHttpOnly</code></td><td>
		578	<p>Should the HttpOnly flag be set on session cookies to prevent client
		579	side script from accessing the session ID? Defaults to
		580	<code>true</code>.</p>
		581	</td></tr><tr id="Attributes_Common Attributes_useRelativeRedirects"><td><code class="attributeName">useRelativeRedirects</code></td><td>
		582	<p>Controls whether HTTP 1.1 and later location headers generated by a
		583	call to
		584	<code>javax.servlet.http.HttpServletResponse#sendRedirect(String)</code>
		585	will use relative or absolute redirects. Relative redirects are more
		586	efficient but may not work with reverse proxies that change the context
		587	path. It should be noted that it is not recommended to use a reverse
		588	proxy to change the context path because of the multiple issues it
		589	creates. Absolute redirects should work with reverse proxies that change
		590	the context path but may cause issues with the
		591	<code>org.apache.catalina.filters.RemoteIpFilter</code> if the filter is
		592	changing the scheme and/or port. If the
		593	<code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code>
		594	<a href="systemprops.html">system property</a> is set to
		595	<code>true</code>, the default value of this attribute will be
		596	<code>false</code>, else the default value will be <code>true</code>.
		597	</p>
		598	</td></tr><tr id="Attributes_Common Attributes_validateClientProvidedNewSessionId"><td><code class="attributeName">validateClientProvidedNewSessionId</code></td><td>
		599	<p>When a client provides the ID for a new session, this attribute
		600	controls whether that ID is validated. The only use case for using a
		601	client provided session ID is to have a common session ID across
		602	multiple web applications. Therefore, any client provided session ID
		603	should already exist in another web application. If this check is
		604	enabled, the client provided session ID will only be used if the session
		605	ID exists in at least one other web application for the current host.
		606	Note that the following additional tests are always applied,
		607	irrespective of this setting:</p>
		608	<ul>
		609	<li>The session ID is provided by a cookie</li>
		610	<li>The session cookie has a path of {@code /}</li>
		611	</ul>
		612	<p>If not specified, the default value of <code>true</code> will be
		613	used.</p>
		614	</td></tr><tr id="Attributes_Common Attributes_wrapperClass"><td><code class="attributeName">wrapperClass</code></td><td>
		615	<p>Java class name of the <code>org.apache.catalina.Wrapper</code>
		616	implementation class that will be used for servlets managed by this
		617	Context. If not specified, a standard default value will be used.</p>
		618	</td></tr><tr id="Attributes_Common Attributes_xmlBlockExternal"><td><code class="attributeName">xmlBlockExternal</code></td><td>
		619	<p>If the value of this flag is <code>true</code>, the parsing of
		620	<code>web.xml</code>, <code>web-fragment.xml</code>,
		621	<code>tomcat-web.xml</code>, <code>.tld</code>, <code>.jspx</code>,
		622	<code>*.tagx</code> and <code>tagPlugins.xml</code> files for this web
		623	application will not permit external entities to be loaded. If not
		624	specified, the default value of <code>true</code> will be used.</p>
		625	</td></tr><tr id="Attributes_Common Attributes_xmlNamespaceAware"><td><code class="attributeName">xmlNamespaceAware</code></td><td>
		626	<p>If the value of this flag is <code>true</code>, the parsing of
		627	<code>web.xml</code>, <code>web-fragment.xml</code> and
		628	<code>tomcat-web.xml</code> files for this web application will be
		629	namespace-aware. Note that <code>.tld</code>, <code>.jspx</code> and
		630	<code>*.tagx</code> files are always parsed using a namespace-aware
		631	parser and that the <code>tagPlugins.xml</code> file (if any) is never
		632	parsed using a namespace-aware parser. Note also that if you turn this
		633	flag on, you should probably also turn <code>xmlValidation</code> on. If
		634	the <code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code>
		635	<a href="systemprops.html">system property</a> is set to
		636	<code>true</code>, the default value of this attribute will be
		637	<code>true</code>, else the default value will be <code>false</code>.
		638	Setting this attribute to <code>true</code> will incur a performance
		639	penalty.</p>
		640	</td></tr><tr id="Attributes_Common Attributes_xmlValidation"><td><code class="attributeName">xmlValidation</code></td><td>
		641	<p>If the value of this flag is <code>true</code>, the parsing of
		642	<code>web.xml</code>, <code>web-fragment.xml</code> and
		643	<code>tomcat-web.xml</code> files for this web application will use a
		644	validating parser. If the
		645	<code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code>
		646	<a href="systemprops.html">system property</a> is set to
		647	<code>true</code>, the default value of this attribute will be
		648	<code>true</code>, else the default value will be <code>false</code>.
		649	Setting this attribute to <code>true</code> will incur a performance
		650	penalty.</p>
		651	</td></tr></table>
		652
		653	</div></div>
		654
		655
		656	<div class="subsection"><h4 id="Standard_Implementation">Standard Implementation</h4><div class="text">
		657
		658	<p>The standard implementation of <strong>Context</strong> is
		659	<strong>org.apache.catalina.core.StandardContext</strong>.
		660	It supports the following additional attributes (in addition to the
		661	common attributes listed above):</p>
		662
		663	<table class="defaultTable"><tr><th style="width: 15%;">
		664	Attribute
		665	</th><th style="width: 85%;">
		666	Description
		667	</th></tr><tr id="Attributes_Standard Implementation_addWebinfClassesResources"><td><code class="attributeName">addWebinfClassesResources</code></td><td>
		668	<p>This attribute controls if, in addition to static resources being
		669	served from <code>META-INF/resources</code> inside web application JAR
		670	files, static resources are also served from
		671	<code>WEB-INF/classes/META-INF/resources</code>. This only applies to
		672	web applications with a major version of 3 or higher. Since this is a
		673	proprietary extension to the Servlet 3 specification, it is disabled by
		674	default. To enable this feature, set the attribute to <code>true</code>.
		675	</p>
		676	</td></tr><tr id="Attributes_Standard Implementation_antiResourceLocking"><td><code class="attributeName">antiResourceLocking</code></td><td>
		677	<p>If <code>true</code>, Tomcat will prevent any file locking.
		678	This will significantly impact startup time of applications,
		679	but allows full webapp hot deploy and undeploy on platforms
		680	or configurations where file locking can occur.
		681	If not specified, the default value is <code>false</code>.</p>
		682
		683	<p>Please note that setting this to <code>true</code> has some side
		684	effects, including the disabling of JSP reloading in a running server:
		685	see <a href="https://bz.apache.org/bugzilla/show_bug.cgi?id=37668">
		686	Bugzilla 37668</a>.</p>
		687
		688	<p>Please note that setting this flag to <code>true</code> in
		689	applications that are outside the <code>appBase</code> for the Host (the
		690	<code>webapps</code> directory by default) will cause the application to
		691	be <strong>deleted</strong> on Tomcat shutdown. You probably don't want
		692	to do this, so think twice before setting antiResourceLocking=true on a
		693	webapp that's outside the <code>appBase</code> for its Host.</p>
		694	</td></tr><tr id="Attributes_Standard Implementation_clearReferencesHttpClientKeepAliveThread"><td><code class="attributeName">clearReferencesHttpClientKeepAliveThread</code></td><td>
		695	<p>If <code>true</code> and an <code>sun.net.www.http.HttpClient</code>
		696	keep-alive timer thread has been started by this web application and is
		697	still running, Tomcat will change the context class loader for that
		698	thread from the web application class loader to the parent of the web
		699	application class loader to prevent a memory leak. Note that the
		700	keep-alive timer thread will stop on its own once the keep-alives all
		701	expire however, on a busy system that might not happen for some time. If
		702	not specified, the default value of <code>true</code> will be used.</p>
		703	</td></tr><tr id="Attributes_Standard Implementation_clearReferencesObjectStreamClassCaches"><td><code class="attributeName">clearReferencesObjectStreamClassCaches</code></td><td>
		704	<p>If <code>true</code>, when the web application is stopped Tomcat
		705	looks for <code>SoftReference</code>s to classes loaded by the web
		706	application in the <code>ObjectStreamClass</code> class used for
		707	serialization and clears any <code>SoftReference</code>s it finds. This
		708	feature uses reflection to identify the <code>SoftReference</code>s and
		709	therefore requires that the command line option
		710	<code>-XaddExports:java.base/java.io=ALL-UNNAMED</code> is set
		711	when running on Java 9 and above. If not specified, the default value of
		712	<code>true</code> will be used.</p>
		713	<p>The memory leak associated with <code>ObjectStreamClass</code> has
		714	been fixed in Java 19 onwards, Java 17.0.4 onwards and Java 11.0.16
		715	onwards. The check will be disabled when running on a version
		716	of Java that contains the fix.</p>
		717	</td></tr><tr id="Attributes_Standard Implementation_clearReferencesRmiTargets"><td><code class="attributeName">clearReferencesRmiTargets</code></td><td>
		718	<p>If <code>true</code>, Tomcat looks for memory leaks associated with
		719	RMI Targets and clears any it finds. This feature uses reflection to
		720	identify the leaks and therefore requires that the command line option
		721	<code>-XaddExports:java.rmi/sun.rmi.transport=ALL-UNNAMED</code> is set
		722	when running on Java 9 and above. Applications without memory leaks
		723	should operate correctly with this attribute set to <code>false</code>.
		724	If not specified, the default value of <code>true</code> will be used.</p>
		725	</td></tr><tr id="Attributes_Standard Implementation_clearReferencesStopThreads"><td><code class="attributeName">clearReferencesStopThreads</code></td><td>
		726	<p>If <code>true</code>, Tomcat attempts to terminate threads that have
		727	been started by the web application. Stopping threads is performed via
		728	the deprecated (for good reason) <code>Thread.stop()</code> method and
		729	is likely to result in instability. As such, enabling this should be
		730	viewed as an option of last resort in a development environment and is
		731	not recommended in a production environment. If not specified, the
		732	default value of <code>false</code> will be used. If this feature is
		733	enabled, web applications may take up to two seconds longer to stop as
		734	executor threads are given up to two seconds to stop gracefully before
		735	<code>Thread.stop()</code> is called on any remaining threads.</p>
		736	</td></tr><tr id="Attributes_Standard Implementation_clearReferencesStopTimerThreads"><td><code class="attributeName">clearReferencesStopTimerThreads</code></td><td>
		737	<p>If <code>true</code>, Tomcat attempts to terminate
		738	<code>java.util.Timer</code> threads that have been started by the web
		739	application. Unlike standard threads, timer threads can be stopped
		740	safely although there may still be side-effects for the application. If
		741	not specified, the default value of <code>false</code> will be used.</p>
		742	</td></tr><tr id="Attributes_Standard Implementation_clearReferencesThreadLocals"><td><code class="attributeName">clearReferencesThreadLocals</code></td><td>
		743	<p>If <code>true</code>, Tomcat attempts to clear
		744	<code>java.lang.ThreadLocal</code> variables that have been populated
		745	with classes loaded by the web application. If not specified, the
		746	default value of <code>true</code> will be used.</p>
		747	</td></tr><tr id="Attributes_Standard Implementation_copyXML"><td><code class="attributeName">copyXML</code></td><td>
		748	<p>Set to <code>true</code> if you want a context XML descriptor
		749	embedded inside the application (located at
		750	<code>/META-INF/context.xml</code>) to be copied to the owning
		751	<a href="host.html">Host</a>'s <code>xmlBase</code> when the application
		752	is deployed. On subsequent starts, the copied context XML descriptor
		753	will be used in preference to any context XML descriptor embedded inside
		754	the application even if the descriptor embedded inside the application
		755	is more recent. The default is <code>false</code>. Note if
		756	the <strong>deployXML</strong> attribute of the owning
		757	<a href="host.html">Host</a> is <code>false</code> or if the
		758	<strong>copyXML</strong> attribute of the owning
		759	<a href="host.html">Host</a> is <code>true</code>, this attribute will
		760	have no effect.</p>
		761	</td></tr><tr id="Attributes_Standard Implementation_jndiExceptionOnFailedWrite"><td><code class="attributeName">jndiExceptionOnFailedWrite</code></td><td>
		762	<p>If <code>true</code>, any attempt by an application to modify the
		763	provided JNDI context with a call to bind(), unbind(),
		764	createSubContext(), destroySubContext() or close() will trigger a
		765	<code>javax.naming.OperationNotSupportedException</code> as required by
		766	section EE.5.3.4 of the Java EE specification. This exception can be
		767	disabled by setting this attribute to <code>false</code> in which case
		768	any calls to modify the JNDI context will return <b>without</b> making
		769	any changes and methods that return values will return
		770	<code>null</code>. If not specified, the specification compliant default
		771	of <code>true</code> will be used.</p>
		772	</td></tr><tr id="Attributes_Standard Implementation_notFoundClassResourceCacheSize"><td><code class="attributeName">notFoundClassResourceCacheSize</code></td><td>
		773	<p>Class resources are not cached by the standard resources
		774	implementation since they are loaded on first use and then the resource
		775	is then no longer required. It does help, however, to cache classes that
		776	are not found as in some scenarios the same class will be searched for
		777	many times and the greater the number of JARs/classes, the longer that
		778	search will take. An LRU cache is used and this attribute controls the
		779	size of that cache. A value of less than 1 disables the cache. If not
		780	specified, the default value of 1000 will be used.</p>
		781	</td></tr><tr id="Attributes_Standard Implementation_renewThreadsWhenStoppingContext"><td><code class="attributeName">renewThreadsWhenStoppingContext</code></td><td>
		782	<p>If <code>true</code>, when this context is stopped, Tomcat renews all
		783	the threads from the thread pool that was used to serve this context.
		784	This also requires that the
		785	<code>ThreadLocalLeakPreventionListener</code> be configured in
		786	<code>server.xml</code> and that the <code>threadRenewalDelay</code>
		787	property of the <code>Executor</code> be >=0. If not specified, the
		788	default value of <code>true</code> will be used.</p>
		789	</td></tr><tr id="Attributes_Standard Implementation_skipMemoryLeakChecksOnJvmShutdown"><td><code class="attributeName">skipMemoryLeakChecksOnJvmShutdown</code></td><td>
		790	<p>If <code>true</code>, Tomcat will not perform the usual memory leak
		791	checks when the web application is stopped if that web application is
		792	stopped as part of a JVM shutdown. If not specified, the default value
		793	of <code>false</code> will be used.</p>
		794	</td></tr><tr id="Attributes_Standard Implementation_unloadDelay"><td><code class="attributeName">unloadDelay</code></td><td>
		795	<p>Number of ms that the container will wait for servlets to unload.
		796	If not specified, the default value is <code>2000</code> ms.</p>
		797	</td></tr><tr id="Attributes_Standard Implementation_unpackWAR"><td><code class="attributeName">unpackWAR</code></td><td>
		798	<p>If <code>false</code>, the <strong>unpackWARs</strong> attribute of
		799	the owning <a href="host.html">Host</a> will be overridden and the WAR
		800	file will not be unpacked. If <code>true</code>, the value of the owning
		801	<a href="host.html">Host</a>'s <strong>unpackWARs</strong>
		802	attribute will determine if the WAR is unpacked. If not specified, the
		803	default value is <code>true</code>.</p>
		804	</td></tr><tr id="Attributes_Standard Implementation_useNaming"><td><code class="attributeName">useNaming</code></td><td>
		805	<p>Set to <code>true</code> (the default) to have Catalina enable a
		806	JNDI <code>InitialContext</code> for this web application that is
		807	compatible with Java2 Enterprise Edition (J2EE) platform
		808	conventions.</p>
		809	</td></tr><tr id="Attributes_Standard Implementation_workDir"><td><code class="attributeName">workDir</code></td><td>
		810	<p>Pathname to a scratch directory to be provided by this Context
		811	for temporary read-write use by servlets within the associated web
		812	application. This directory will be made visible to servlets in the
		813	web application by a servlet context attribute (of type
		814	<code>java.io.File</code>) named
		815	<code>javax.servlet.context.tempdir</code> as described in the
		816	Servlet Specification. If not specified, a suitable directory
		817	underneath <code>$CATALINA_BASE/work</code> will be provided.</p>
		818	</td></tr></table>
		819
		820	</div></div>
		821
		822
		823	</div><h3 id="Nested_Components">Nested Components</h3><div class="text">
		824
		825	<p>You can nest at most one instance of the following utility components
		826	by nesting a corresponding element inside your <strong>Context</strong>
		827	element:</p>
		828	<ul>
		829	<li><a href="cookie-processor.html"><strong>Cookie Processor</strong></a> -
		830	Configure parsing and generation of HTTP cookie headers.</li>
		831	<li><a href="loader.html"><strong>Loader</strong></a> -
		832	Configure the web application class loader that will be used to load
		833	servlet and bean classes for this web application. Normally, the
		834	default configuration of the class loader will be sufficient.</li>
		835	<li><a href="manager.html"><strong>Manager</strong></a> -
		836	Configure the session manager that will be used to create, destroy,
		837	and persist HTTP sessions for this web application. Normally, the
		838	default configuration of the session manager will be sufficient.</li>
		839	<li><a href="realm.html"><strong>Realm</strong></a> -
		840	Configure a realm that will allow its
		841	database of users, and their associated roles, to be utilized solely
		842	for this particular web application. If not specified, this web
		843	application will utilize the Realm associated with the owning
		844	<a href="host.html">Host</a> or <a href="engine.html">Engine</a>.</li>
		845	<li><a href="resources.html"><strong>Resources</strong></a> -
		846	Configure the resource manager that will be used to access the static
		847	resources associated with this web application. Normally, the
		848	default configuration of the resource manager will be sufficient.</li>
		849	<li><strong>WatchedResource</strong> - The auto deployer will monitor the
		850	specified static resource of the web application for updates, and will
		851	reload the web application if it is updated. The content of this element
		852	must be a string.</li>
		853	<li><a href="jar-scanner.html"><strong>JarScanner</strong></a> -
		854	Configure the Jar Scanner that will be used to scan the web application
		855	for JAR files and directories of class files. It is typically used during
		856	web application start to identify configuration files such as TLDs o
		857	web-fragment.xml files that must be processed as part of the web
		858	application initialisation. Normally, the default Jar Scanner
		859	configuration will be sufficient.</li>
		860	</ul>
		861
		862	</div><h3 id="Special_Features">Special Features</h3><div class="text">
		863
		864
		865	<div class="subsection"><h4 id="Logging">Logging</h4><div class="text">
		866
		867	<p>A context is associated with the
		868	<code>org.apache.catalina.core.ContainerBase.[enginename].[hostname].[path]</code>
		869	log category. Note that the brackets are actually part of the name, don't omit them.</p>
		870
		871	</div></div>
		872
		873
		874	<div class="subsection"><h4 id="Access_Logs">Access Logs</h4><div class="text">
		875
		876	<p>When you run a web server, one of the output files normally generated
		877	is an <em>access log</em>, which generates one line of information for
		878	each request processed by the server, in a standard format. Catalina
		879	includes an optional <a href="valve.html">Valve</a> implementation that
		880	can create access logs in the same standard format created by web servers,
		881	or in any number of custom formats.</p>
		882
		883	<p>You can ask Catalina to create an access log for all requests
		884	processed by an <a href="engine.html">Engine</a>,
		885	<a href="host.html">Host</a>, or <a href="context.html">Context</a>
		886	by nesting a <a href="valve.html">Valve</a> element like this:</p>
		887
		888	<div class="codeBox"><pre><code><Context>
		889	...
		890	<Valve className="org.apache.catalina.valves.AccessLogValve"
		891	prefix="localhost_access_log" suffix=".txt"
		892	pattern="common"/>
		893	...
		894	</Context></code></pre></div>
		895
		896	<p>See <a href="valve.html#Access_Logging">Access Logging Valves</a>
		897	for more information on the configuration attributes that are
		898	supported.</p>
		899
		900	</div></div>
		901
		902
		903	<div class="subsection"><h4 id="Automatic_Context_Configuration">Automatic Context Configuration</h4><div class="text">
		904
		905	<p>If you use the standard <strong>Context</strong> implementation,
		906	the following configuration steps occur automatically when Catalina
		907	is started, or whenever this web application is reloaded. No special
		908	configuration is required to enable this feature.</p>
		909
		910	<ul>
		911	<li>If you have not declared your own <a href="loader.html">Loader</a>
		912	element, a standard web application class loader will be configured.
		913	</li>
		914	<li>If you have not declared your own <a href="manager.html">Manager</a>
		915	element, a standard session manager will be configured.</li>
		916	<li>If you have not declared your own <a href="resources.html">Resources</a>
		917	element, a standard resources manager will be configured.</li>
		918	<li>The web application properties listed in <code>conf/web.xml</code>
		919	will be processed as defaults for this web application. This is used
		920	to establish default mappings (such as mapping the <code>*.jsp</code>
		921	extension to the corresponding JSP servlet), and other standard
		922	features that apply to all web applications.</li>
		923	<li>The web application properties listed in the
		924	<code>/WEB-INF/tomcat-web.xml</code> resource for this web application
		925	will be processed (if this resource exists), taking precedence over the
		926	defaults.</li>
		927	<li>The web application properties listed in the
		928	<code>/WEB-INF/web.xml</code> resource for this web application
		929	will be processed (if this resource exists).</li>
		930	<li>If your web application has specified security constraints that might
		931	require user authentication, an appropriate Authenticator that
		932	implements the login method you have selected will be configured.</li>
		933	</ul>
		934
		935	</div></div>
		936
		937
		938	<div class="subsection"><h4 id="Context_Parameters">Context Parameters</h4><div class="text">
		939
		940	<p>You can configure named values that will be made visible to the
		941	web application as servlet context initialization parameters by nesting
		942	<code><Parameter></code> elements inside this element. For
		943	example, you can create an initialization parameter like this:</p>
		944	<div class="codeBox"><pre><code><Context>
		945	...
		946	<Parameter name="companyName" value="My Company, Incorporated"
		947	override="false"/>
		948	...
		949	</Context></code></pre></div>
		950
		951	<p>This is equivalent to the inclusion of the following element in the
		952	web application deployment descriptor (<code>/WEB-INF/web.xml</code>):
		953	</p>
		954	<div class="codeBox"><pre><code><context-param>
		955	<param-name>companyName</param-name>
		956	<param-value>My Company, Incorporated</param-value>
		957	</context-param></code></pre></div>
		958	<p>but does <em>not</em> require modification of the deployment descriptor
		959	to customize this value.</p>
		960
		961	<p>The valid attributes for a <code><Parameter></code> element
		962	are as follows:</p>
		963
		964	<table class="defaultTable"><tr><th style="width: 15%;">
		965	Attribute
		966	</th><th style="width: 85%;">
		967	Description
		968	</th></tr><tr id="Special Features_Context Parameters_description"><td><code class="attributeName">description</code></td><td>
		969	<p>Optional, human-readable description of this context
		970	initialization parameter.</p>
		971	</td></tr><tr id="Special Features_Context Parameters_name"><td><strong><code class="attributeName">name</code></strong></td><td>
		972	<p>The name of the context initialization parameter to be created.</p>
		973	</td></tr><tr id="Special Features_Context Parameters_override"><td><code class="attributeName">override</code></td><td>
		974	<p>Set this to <code>false</code> if you do <strong>not</strong> want
		975	a <code><context-param></code> for the same parameter name,
		976	found in the web application deployment descriptor, to override the
		977	value specified here. By default, overrides are allowed.</p>
		978	</td></tr><tr id="Special Features_Context Parameters_value"><td><strong><code class="attributeName">value</code></strong></td><td>
		979	<p>The parameter value that will be presented to the application
		980	when requested by calling
		981	<code>ServletContext.getInitParameter()</code>.</p>
		982	</td></tr></table>
		983
		984	</div></div>
		985
		986
		987	<div class="subsection"><h4 id="Environment_Entries">Environment Entries</h4><div class="text">
		988
		989	<p>You can configure named values that will be made visible to the
		990	web application as environment entry resources, by nesting
		991	<code><Environment></code> entries inside this element. For
		992	example, you can create an environment entry like this:</p>
		993	<div class="codeBox"><pre><code><Context>
		994	...
		995	<Environment name="maxExemptions" value="10"
		996	type="java.lang.Integer" override="false"/>
		997	...
		998	</Context></code></pre></div>
		999
		1000	<p>This is equivalent to the inclusion of the following element in the
		1001	web application deployment descriptor (<code>/WEB-INF/web.xml</code>):
		1002	</p>
		1003	<div class="codeBox"><pre><code><env-entry>
		1004	<env-entry-name>maxExemptions</env-entry-name>
		1005	<env-entry-value>10</env-entry-value>
		1006	<env-entry-type>java.lang.Integer</env-entry-type>
		1007	</env-entry></code></pre></div>
		1008	<p>but does <em>not</em> require modification of the deployment descriptor
		1009	to customize this value.</p>
		1010
		1011	<p>The valid attributes for an <code><Environment></code> element
		1012	are as follows:</p>
		1013
		1014	<table class="defaultTable"><tr><th style="width: 15%;">
		1015	Attribute
		1016	</th><th style="width: 85%;">
		1017	Description
		1018	</th></tr><tr id="Special Features_Environment Entries_description"><td><code class="attributeName">description</code></td><td>
		1019	<p>Optional, human-readable description of this environment entry.</p>
		1020	</td></tr><tr id="Special Features_Environment Entries_name"><td><strong><code class="attributeName">name</code></strong></td><td>
		1021	<p>The name of the environment entry to be created, relative to the
		1022	<code>java:comp/env</code> context.</p>
		1023	</td></tr><tr id="Special Features_Environment Entries_override"><td><code class="attributeName">override</code></td><td>
		1024	<p>Set this to <code>false</code> if you do <strong>not</strong> want
		1025	an <code><env-entry></code> for the same environment entry name,
		1026	found in the web application deployment descriptor, to override the
		1027	value specified here. By default, overrides are allowed.</p>
		1028	</td></tr><tr id="Special Features_Environment Entries_type"><td><strong><code class="attributeName">type</code></strong></td><td>
		1029	<p>The fully qualified Java class name expected by the web application
		1030	for this environment entry. Must be a legal value for
		1031	<code><env-entry-type></code> in the web application deployment
		1032	descriptor.</p>
		1033	</td></tr><tr id="Special Features_Environment Entries_value"><td><strong><code class="attributeName">value</code></strong></td><td>
		1034	<p>The parameter value that will be presented to the application
		1035	when requested from the JNDI context. This value must be convertible
		1036	to the Java type defined by the <code>type</code> attribute.</p>
		1037	</td></tr></table>
		1038
		1039	</div></div>
		1040
		1041
		1042	<div class="subsection"><h4 id="Lifecycle_Listeners">Lifecycle Listeners</h4><div class="text">
		1043
		1044	<p>If you have implemented a Java object that needs to know when this
		1045	<strong>Context</strong> is started or stopped, you can declare it by
		1046	nesting a <strong>Listener</strong> element inside this element. The
		1047	class name you specify must implement the
		1048	<code>org.apache.catalina.LifecycleListener</code> interface, and
		1049	the class must be packaged in a jar and placed in the
		1050	<code>$CATALINA_HOME/lib</code> directory.
		1051	It will be notified about the occurrence of the corresponding
		1052	lifecycle events. Configuration of such a listener looks like this:</p>
		1053
		1054	<div class="codeBox"><pre><code><Context>
		1055	...
		1056	<Listener className="com.mycompany.mypackage.MyListener" ... >
		1057	...
		1058	</Context></code></pre></div>
		1059
		1060	<p>Note that a Listener can have any number of additional properties
		1061	that may be configured from this element. Attribute names are matched
		1062	to corresponding JavaBean property names using the standard property
		1063	method naming patterns.</p>
		1064
		1065	</div></div>
		1066
		1067
		1068	<div class="subsection"><h4 id="Request_Filters">Request Filters</h4><div class="text">
		1069
		1070	<p>You can ask Catalina to check the IP address, or host name, on every
		1071	incoming request directed to the surrounding
		1072	<a href="engine.html">Engine</a>, <a href="host.html">Host</a>, or
		1073	<a href="context.html">Context</a> element. The remote address or name
		1074	will be checked against configured "accept" and/or "deny"
		1075	filters, which are defined using <code>java.util.regex</code> Regular
		1076	Expression syntax. Requests that come from locations that are
		1077	not accepted will be rejected with an HTTP "Forbidden" error.
		1078	Example filter declarations:</p>
		1079
		1080	<div class="codeBox"><pre><code><Context>
		1081	...
		1082	<Valve className="org.apache.catalina.valves.RemoteHostValve"
		1083	allow=".*\.mycompany\.com\|www\.yourcompany\.com"/>
		1084	<Valve className="org.apache.catalina.valves.RemoteCIDRValve"
		1085	deny="192.168.1.0/24"/>
		1086	...
		1087	</Context></code></pre></div>
		1088
		1089	<p>See <a href="valve.html#Remote_Address_Filter">Remote Address Filter</a>
		1090	and <a href="valve.html#Remote_Host_Filter">Remote Host Filter</a> for
		1091	more information about the configuration options that are supported.</p>
		1092
		1093	</div></div>
		1094
		1095
		1096	<div class="subsection"><h4 id="Resource_Definitions">Resource Definitions</h4><div class="text">
		1097
		1098	<p>You can declare the characteristics of the resource
		1099	to be returned for JNDI lookups of <code><resource-ref></code> and
		1100	<code><resource-env-ref></code> elements in the web application
		1101	deployment descriptor. You <strong>MUST</strong> also define
		1102	the needed resource parameters as attributes of the <code>Resource</code>
		1103	element, to configure the object factory to be used (if not known to Tomcat
		1104	already), and the properties used to configure that object factory.</p>
		1105
		1106	<p>For example, you can create a resource definition like this:</p>
		1107	<div class="codeBox"><pre><code><Context>
		1108	...
		1109	<Resource name="jdbc/EmployeeDB" auth="Container"
		1110	type="javax.sql.DataSource"
		1111	description="Employees Database for HR Applications"/>
		1112	...
		1113	</Context></code></pre></div>
		1114
		1115	<p>This is equivalent to the inclusion of the following element in the
		1116	web application deployment descriptor (<code>/WEB-INF/web.xml</code>):</p>
		1117	<div class="codeBox"><pre><code><resource-ref>
		1118	<description>Employees Database for HR Applications</description>
		1119	<res-ref-name>jdbc/EmployeeDB</res-ref-name>
		1120	<res-ref-type>javax.sql.DataSource</res-ref-type>
		1121	<res-auth>Container</res-auth>
		1122	</resource-ref></code></pre></div>
		1123
		1124	<p>but does <em>not</em> require modification of the deployment
		1125	descriptor to customize this value.</p>
		1126
		1127	<p>The valid attributes for a <code><Resource></code> element
		1128	are as follows:</p>
		1129
		1130	<table class="defaultTable"><tr><th style="width: 15%;">
		1131	Attribute
		1132	</th><th style="width: 85%;">
		1133	Description
		1134	</th></tr><tr id="Special Features_Resource Definitions_auth"><td><code class="attributeName">auth</code></td><td>
		1135	<p>Specify whether the web Application code signs on to the
		1136	corresponding resource manager programmatically, or whether the
		1137	Container will sign on to the resource manager on behalf of the
		1138	application. The value of this attribute must be
		1139	<code>Application</code> or <code>Container</code>. This
		1140	attribute is <strong>required</strong> if the web application
		1141	will use a <code><resource-ref></code> element in the web
		1142	application deployment descriptor, but is optional if the
		1143	application uses a <code><resource-env-ref></code> instead.</p>
		1144	</td></tr><tr id="Special Features_Resource Definitions_closeMethod"><td><code class="attributeName">closeMethod</code></td><td>
		1145	<p>Name of the zero-argument method to call on a singleton resource when
		1146	it is no longer required. This is intended to speed up clean-up of
		1147	resources that would otherwise happen as part of garbage collection.
		1148	This attribute is ignored if the <code>singleton</code> attribute is
		1149	<code>false</code>.</p>
		1150	<p>For <code>javax.sql.DataSource</code> and
		1151	<code>javax.sql.XADataSource</code> resources that implement
		1152	<code>AutoCloseable</code> such as Apache Commons DBCP 2 and the default
		1153	Apache Tomcat connection pool, this attribute is defaults to
		1154	<code>close</code>. This may be disabled by setting the attribute to the
		1155	empty string. For all other resource types no default is defined and no
		1156	close method will be called by default.</p>
		1157	</td></tr><tr id="Special Features_Resource Definitions_description"><td><code class="attributeName">description</code></td><td>
		1158	<p>Optional, human-readable description of this resource.</p>
		1159	</td></tr><tr id="Special Features_Resource Definitions_name"><td><strong><code class="attributeName">name</code></strong></td><td>
		1160	<p>The name of the resource to be created, relative to the
		1161	<code>java:comp/env</code> context.</p>
		1162	</td></tr><tr id="Special Features_Resource Definitions_scope"><td><code class="attributeName">scope</code></td><td>
		1163	<p>Specify whether connections obtained through this resource
		1164	manager can be shared. The value of this attribute must be
		1165	<code>Shareable</code> or <code>Unshareable</code>. By default,
		1166	connections are assumed to be shareable.</p>
		1167	</td></tr><tr id="Special Features_Resource Definitions_singleton"><td><code class="attributeName">singleton</code></td><td>
		1168	<p>Specify whether this resource definition is for a singleton resource,
		1169	i.e. one where there is only a single instance of the resource. If this
		1170	attribute is <code>true</code>, multiple JNDI lookups for this resource
		1171	will return the same object. If this attribute is <code>false</code>,
		1172	multiple JNDI lookups for this resource will return different objects.
		1173	This attribute must be <code>true</code> for
		1174	<code>javax.sql.DataSource</code> resources to enable JMX registration
		1175	of the DataSource. The value of this attribute must be <code>true</code>
		1176	or <code>false</code>. By default, this attribute is <code>true</code>.
		1177	</p>
		1178	</td></tr><tr id="Special Features_Resource Definitions_type"><td><strong><code class="attributeName">type</code></strong></td><td>
		1179	<p>The fully qualified Java class name expected by the web
		1180	application when it performs a lookup for this resource.</p>
		1181	</td></tr></table>
		1182
		1183
		1184	</div></div>
		1185
		1186
		1187	<div class="subsection"><h4 id="Resource_Links">Resource Links</h4><div class="text">
		1188
		1189	<p>This element is used to create a link to a global JNDI resource. Doing
		1190	a JNDI lookup on the link name will then return the linked global
		1191	resource.</p>
		1192
		1193	<p>For example, you can create a resource link like this:</p>
		1194	<div class="codeBox"><pre><code><Context>
		1195	...
		1196	<ResourceLink name="linkToGlobalResource"
		1197	global="simpleValue"
		1198	type="java.lang.Integer"
		1199	...
		1200	</Context></code></pre></div>
		1201
		1202	<p>The valid attributes for a <code><ResourceLink></code> element
		1203	are as follows:</p>
		1204
		1205	<table class="defaultTable"><tr><th style="width: 15%;">
		1206	Attribute
		1207	</th><th style="width: 85%;">
		1208	Description
		1209	</th></tr><tr id="Special Features_Resource Links_global"><td><strong><code class="attributeName">global</code></strong></td><td>
		1210	<p>The name of the linked global resource in the
		1211	global JNDI context.</p>
		1212	</td></tr><tr id="Special Features_Resource Links_name"><td><strong><code class="attributeName">name</code></strong></td><td>
		1213	<p>The name of the resource link to be created, relative to the
		1214	<code>java:comp/env</code> context.</p>
		1215	</td></tr><tr id="Special Features_Resource Links_type"><td><strong><code class="attributeName">type</code></strong></td><td>
		1216	<p>The fully qualified Java class name expected by the web
		1217	application when it performs a lookup for this resource link.</p>
		1218	</td></tr><tr id="Special Features_Resource Links_factory"><td><code class="attributeName">factory</code></td><td>
		1219	<p>The fully qualified Java class name for the class creating these objects.
		1220	This class should implement the <code>javax.naming.spi.ObjectFactory</code> interface.</p>
		1221	</td></tr></table>
		1222
		1223	<p>When the attribute <code>factory="org.apache.naming.factory.DataSourceLinkFactory"</code> the resource link can be used with
		1224	two additional attributes to allow a shared data source to be used with different credentials.
		1225	When these two additional attributes are used in combination with the <code>javax.sql.DataSource</code>
		1226	type, different contexts can share a global data source with different credentials.
		1227	Under the hood, what happens is that a call to <a href="https://docs.oracle.com/javase/8/docs/api/javax/sql/DataSource.html#getConnection()"><code>getConnection()</code></a>
		1228	is simply translated to a call <a href="https://docs.oracle.com/javase/8/docs/api/javax/sql/DataSource.html#getConnection(java.lang.String,%20java.lang.String)">
		1229	<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,
		1230	yet be able to control connections (or pools) in the global configuration.
		1231	</p>
		1232	<table class="defaultTable"><tr><th style="width: 15%;">
		1233	Attribute
		1234	</th><th style="width: 85%;">
		1235	Description
		1236	</th></tr><tr id="Special Features_Resource Links_username"><td><code class="attributeName">username</code></td><td>
		1237	<p><code>username</code> value for the <code>getConnection(username, password)</code>
		1238	call on the linked global DataSource.
		1239	</p>
		1240	</td></tr><tr id="Special Features_Resource Links_password"><td><code class="attributeName">password</code></td><td>
		1241	<p><code>password</code> value for the <code>getConnection(username, password)</code>
		1242	call on the linked global DataSource.
		1243	</p>
		1244	</td></tr></table>
		1245	<p>Shared Data Source Example:</p>
		1246	<p><strong>Warning:</strong> This feature works only if the global DataSource
		1247	supports <code>getConnection(username, password)</code> method.
		1248	<a href="https://commons.apache.org/dbcp/">Apache Commons DBCP 2</a> pool that
		1249	Tomcat uses by default does not support it. See its Javadoc for
		1250	<code>BasicDataSource</code> class.
		1251	<a href="../jdbc-pool.html">Apache Tomcat JDBC pool</a> does support it,
		1252	but by default this support is disabled and can be enabled by
		1253	<code>alternateUsernameAllowed</code> attribute. See its documentation
		1254	for details.</p>
		1255	<div class="codeBox"><pre><code><GlobalNamingResources>
		1256	...
		1257	<Resource name="sharedDataSource"
		1258	global="sharedDataSource"
		1259	type="javax.sql.DataSource"
		1260	factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
		1261	alternateUsernameAllowed="true"
		1262	username="bar"
		1263	password="barpass"
		1264	...
		1265	...
		1266	</GlobalNamingResources>
		1267
		1268	<Context path="/foo"...>
		1269	...
		1270	<ResourceLink
		1271	name="appDataSource"
		1272	global="sharedDataSource"
		1273	type="javax.sql.DataSource"
		1274	factory="org.apache.naming.factory.DataSourceLinkFactory"
		1275	username="foo"
		1276	password="foopass"
		1277	...
		1278	</Context>
		1279	<Context path="/bar"...>
		1280	...
		1281	<ResourceLink
		1282	name="appDataSource"
		1283	global="sharedDataSource"
		1284	type="javax.sql.DataSource"
		1285	...
		1286	</Context></code></pre></div>
		1287	<p>When a request for <code>getConnection()</code> is made in the
		1288	<code>/foo</code> context, the request is translated into
		1289	<code>getConnection("foo","foopass")</code>,
		1290	while a request in the <code>/bar</code> gets passed straight through.</p>
		1291	</div></div>
		1292
		1293	<div class="subsection"><h4 id="Transaction">Transaction</h4><div class="text">
		1294
		1295	<p>You can declare the characteristics of the UserTransaction
		1296	to be returned for JNDI lookup for <code>java:comp/UserTransaction</code>.
		1297	You <strong>MUST</strong> define an object factory class to instantiate
		1298	this object as well as the needed resource parameters as attributes of the
		1299	<code>Transaction</code>
		1300	element, and the properties used to configure that object factory.</p>
		1301
		1302	<p>The valid attributes for the <code><Transaction></code> element
		1303	are as follows:</p>
		1304
		1305	<table class="defaultTable"><tr><th style="width: 15%;">
		1306	Attribute
		1307	</th><th style="width: 85%;">
		1308	Description
		1309	</th></tr><tr id="Special Features_Transaction_factory"><td><strong><code class="attributeName">factory</code></strong></td><td>
		1310	<p>The class name for the JNDI object factory.</p>
		1311	</td></tr></table>
		1312
		1313	</div></div>
		1314
		1315	</div></div></div></div></div><footer><div id="footer">
		1316	Copyright © 1999-2025, The Apache Software Foundation
		1317	<br>
		1318	Apache Tomcat, Tomcat, Apache, the Apache Tomcat logo and the Apache logo
		1319	are either registered trademarks or trademarks of the Apache Software
		1320	Foundation.
		1321	</div></footer></div></body></html>

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