225 lines
16 KiB
HTML
225 lines
16 KiB
HTML
<html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat 7 Configuration Reference (7.0.108) - The Loader Component</title><meta name="author" content="Craig R. McClanahan"><style type="text/css" media="print">
|
|
.noPrint {display: none;}
|
|
td#mainBody {width: 100%;}
|
|
</style><style type="text/css">
|
|
code {background-color:rgb(224,255,255);padding:0 0.1em;}
|
|
code.attributeName, code.propertyName {background-color:transparent;}
|
|
|
|
|
|
table {
|
|
border-collapse: collapse;
|
|
text-align: left;
|
|
}
|
|
table *:not(table) {
|
|
/* Prevent border-collapsing for table child elements like <div> */
|
|
border-collapse: separate;
|
|
}
|
|
|
|
th {
|
|
text-align: left;
|
|
}
|
|
|
|
|
|
div.codeBox pre code, code.attributeName, code.propertyName, code.noHighlight, .noHighlight code {
|
|
background-color: transparent;
|
|
}
|
|
div.codeBox {
|
|
overflow: auto;
|
|
margin: 1em 0;
|
|
}
|
|
div.codeBox pre {
|
|
margin: 0;
|
|
padding: 4px;
|
|
border: 1px solid #999;
|
|
border-radius: 5px;
|
|
background-color: #eff8ff;
|
|
display: table; /* To prevent <pre>s from taking the complete available width. */
|
|
/*
|
|
When it is officially supported, use the following CSS instead of display: table
|
|
to prevent big <pre>s from exceeding the browser window:
|
|
max-width: available;
|
|
width: min-content;
|
|
*/
|
|
}
|
|
|
|
div.codeBox pre.wrap {
|
|
white-space: pre-wrap;
|
|
}
|
|
|
|
|
|
table.defaultTable tr, table.detail-table tr {
|
|
border: 1px solid #CCC;
|
|
}
|
|
|
|
table.defaultTable tr:nth-child(even), table.detail-table tr:nth-child(even) {
|
|
background-color: #FAFBFF;
|
|
}
|
|
|
|
table.defaultTable tr:nth-child(odd), table.detail-table tr:nth-child(odd) {
|
|
background-color: #EEEFFF;
|
|
}
|
|
|
|
table.defaultTable th, table.detail-table th {
|
|
background-color: #88b;
|
|
color: #fff;
|
|
}
|
|
|
|
table.defaultTable th, table.defaultTable td, table.detail-table th, table.detail-table td {
|
|
padding: 5px 8px;
|
|
}
|
|
|
|
|
|
p.notice {
|
|
border: 1px solid rgb(255, 0, 0);
|
|
background-color: rgb(238, 238, 238);
|
|
color: rgb(0, 51, 102);
|
|
padding: 0.5em;
|
|
margin: 1em 2em 1em 1em;
|
|
}
|
|
</style></head><body bgcolor="#ffffff" text="#000000" link="#525D76" alink="#525D76" vlink="#525D76"><table border="0" width="100%" cellspacing="0"><!--PAGE HEADER--><tr><td><!--PROJECT LOGO--><a href="https://tomcat.apache.org/"><img src="../images/tomcat.gif" align="right" alt="
|
|
The Apache Tomcat Servlet/JSP Container
|
|
" border="0"></a></td><td><h1><font face="arial,helvetica,sanserif">Apache Tomcat 7</font></h1><font face="arial,helvetica,sanserif">Version 7.0.108, Jan 28 2021</font></td><td><!--APACHE LOGO--><a href="http://www.apache.org/"><img src="../images/asf-logo.svg" align="right" alt="Apache Logo" border="0" style="width: 266px;height: 83px;"></a></td></tr></table><table border="0" width="100%" cellspacing="4"><!--HEADER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><tr><!--LEFT SIDE NAVIGATION--><td width="20%" valign="top" 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><li><a href="https://wiki.apache.org/tomcat/FAQ">FAQ</a></li><li><a href="#comments_section">User Comments</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="jar-scanner.html">JarScanner</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><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>The Loader Component</h1><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>
|
|
<ul><li><a href="#Introduction">Introduction</a></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><li><a href="#VirtualWebappLoader_Implementation">VirtualWebappLoader 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></ol></li></ul>
|
|
</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>
|
|
|
|
<p>The <strong>Loader</strong> element represents the <em>web
|
|
application class loader</em> that will be used to load Java
|
|
classes and resources for your web application. Such
|
|
a class loader must follow the requirements of the Servlet
|
|
Specification, and load classes from the following locations:</p>
|
|
<ul>
|
|
<li>From the <code>/WEB-INF/classes</code> directory inside your
|
|
web application.</li>
|
|
<li>From JAR files in the <code>/WEB-INF/lib</code> directory
|
|
inside your web application.</li>
|
|
<li>From resources made available by Catalina to all web
|
|
applications globally.</li>
|
|
</ul>
|
|
|
|
<p>A Loader element MAY be nested inside a <a href="context.html">Context</a>
|
|
component. If it is not included, a default Loader configuration will be
|
|
created automatically, which is sufficient for most requirements.</p>
|
|
|
|
<p>For a more in-depth description of the class loader hierarchy
|
|
that is implemented by Catalina, see <a href="../class-loader-howto.html">the ClassLoader HowTo</a>.</p>
|
|
|
|
<p><em>The description below uses the variable name $CATALINA_BASE to refer the
|
|
base directory against which most relative paths are resolved. If you have
|
|
not configured Tomcat for multiple instances by setting a CATALINA_BASE
|
|
directory, then $CATALINA_BASE will be set to the value of $CATALINA_HOME,
|
|
the directory into which you have installed Tomcat.</em></p>
|
|
|
|
</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>
|
|
|
|
<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>
|
|
|
|
<p>All implementations of <strong>Loader</strong>
|
|
support the following attributes:</p>
|
|
|
|
<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 class="attributeName">className</code></td><td align="left" valign="center">
|
|
<p>Java class name of the implementation to use. This class must
|
|
implement the <code>org.apache.catalina.Loader</code> interface.
|
|
If not specified, the standard value (defined below) will be used.</p>
|
|
</td></tr><tr><td align="left" valign="center"><code class="attributeName">delegate</code></td><td align="left" valign="center">
|
|
<p>Set to <code>true</code> if you want the class loader to follow
|
|
the standard Java2 delegation model, and attempt to load classes from
|
|
parent class loaders <strong>before</strong> looking inside the web
|
|
application. Set to <code>false</code> (the default) to have the
|
|
class loader look inside the web application first, before asking
|
|
parent class loaders to find requested classes or resources.</p>
|
|
</td></tr><tr><td align="left" valign="center"><code class="attributeName">reloadable</code></td><td align="left" valign="center">
|
|
<p>Set to <code>true</code> if you want Catalina to monitor classes in
|
|
<code>/WEB-INF/classes/</code> and <code>/WEB-INF/lib</code> for
|
|
changes, and automatically reload the web application if a change
|
|
is detected. This feature is very useful during application
|
|
development, but it requires significant runtime overhead and is
|
|
not recommended for use on deployed production applications. You
|
|
can use the <a href="../manager-howto.html">Manager</a> web
|
|
application, however, to trigger reloads of deployed applications
|
|
on demand.</p>
|
|
|
|
<p><strong>NOTE</strong> - The value for this property will be
|
|
inherited from the <code>reloadable</code> attribute you set on
|
|
the surrounding <a href="context.html">Context</a> component,
|
|
and any value you explicitly set here will be replaced.</p>
|
|
</td></tr></table>
|
|
|
|
</blockquote></td></tr></table>
|
|
|
|
|
|
<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>
|
|
|
|
<p>The standard implementation of <strong>Loader</strong> is
|
|
<strong>org.apache.catalina.loader.WebappLoader</strong>.
|
|
It supports the following additional attributes (in addition to the
|
|
common attributes listed above):</p>
|
|
|
|
<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 class="attributeName">loaderClass</code></td><td align="left" valign="center">
|
|
<p>Java class name of the <code>java.lang.ClassLoader</code>
|
|
implementation class to use. If not specified, the default value is
|
|
<code>org.apache.catalina.loader.WebappClassLoader</code>. Custom
|
|
<strong>loaderClass</strong> implementations must extend
|
|
<code>org.apache.catalina.loader.WebappClassLoaderBase</code>.The
|
|
default <strong>loaderClass</strong> is not parallel capable. A parallel
|
|
capable <strong>loaderClass</strong> is available when running on a Java
|
|
7 or higher JRE and can be used by specifying
|
|
<code>org.apache.catalina.loader.ParallelWebappClassLoader</code>.</p>
|
|
</td></tr><tr><td align="left" valign="center"><code class="attributeName">searchExternalFirst</code></td><td align="left" valign="center">
|
|
<p>Set to <code>true</code> if you want repositories outside
|
|
of <code>WEB-INF/classes</code> and <code>WEB-INF/lib</code> to
|
|
be searched first. Default value is <code>false</code>.</p>
|
|
</td></tr><tr><td align="left" valign="center"><code class="attributeName">jarOpenInterval</code></td><td align="left" valign="center">
|
|
<p>The interval in milliseconds to keep all jar files open if no jar
|
|
is accessed. The default value is <code>90000</code> milliseconds.
|
|
A non-positive interval indicates keeping jars always open.
|
|
</p>
|
|
</td></tr></table>
|
|
|
|
</blockquote></td></tr></table>
|
|
|
|
<table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="VirtualWebappLoader Implementation"><!--()--></a><a name="VirtualWebappLoader_Implementation"><strong>VirtualWebappLoader Implementation</strong></a></font></td></tr><tr><td><blockquote>
|
|
|
|
<p>This implementation of <strong>Loader</strong> is
|
|
<strong>org.apache.catalina.loader.VirtualWebappLoader</strong>.
|
|
It extends <code>WebappLoader</code> and supports the following
|
|
additional attributes</p>
|
|
|
|
<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 class="attributeName">virtualClasspath</code></td><td align="left" valign="center">
|
|
<p>Additional repositories to search for resources.
|
|
Multiple values can be joined using <code>;</code>
|
|
as a separator.</p>
|
|
<p>Leading and trailing whitespaces in values are ignored.
|
|
If a value does not point to an existing directory or
|
|
<code>*.jar</code> file, it is silently skipped.
|
|
Diagnostic messages can be seen if you enable debug logging for
|
|
the VirtualWebappLoader class.
|
|
</p>
|
|
<p>Example: <code>virtualClasspath="${catalina.base}/myapp_config"</code></p>
|
|
</td></tr><tr><td align="left" valign="center"><code class="attributeName">searchVirtualFirst</code></td><td align="left" valign="center">
|
|
<p>Set to <code>true</code> if you want the virtual
|
|
class path to be searched before
|
|
<code>WEB-INF/classes</code> and <code>WEB-INF/lib</code>.
|
|
Default value is <code>false</code>.</p>
|
|
<p>If searched before, resources located in the virtual
|
|
class path take precendence over resources with the same
|
|
name contained in the webapp.</p>
|
|
</td></tr></table>
|
|
|
|
</blockquote></td></tr></table>
|
|
|
|
|
|
</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>
|
|
|
|
<p>No components may be nested inside a <strong>Loader</strong> element.</p>
|
|
|
|
</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>
|
|
|
|
<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>
|
|
|
|
<p>A loader is associated with the log category based on its classname.</p>
|
|
|
|
</blockquote></td></tr></table>
|
|
|
|
</blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font color="#525D76" size="-1"><em>
|
|
Copyright © 1999-2021, Apache Software Foundation
|
|
</em></font></div></td></tr></table></body></html> |