206 lines
14 KiB
HTML
206 lines
14 KiB
HTML
<!DOCTYPE html SYSTEM "about:legacy-compat">
|
|
<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>Application Developer's Guide (11.0.1) - Deployment</title><meta name="author" content="Craig R. McClanahan"></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>Application Developer's Guide</h1><div class="versionInfo">
|
|
Version 11.0.1,
|
|
<time datetime="2024-11-06">Nov 6 2024</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">App Dev Guide 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>Contents</h2><ul><li><a href="index.html">Contents</a></li><li><a href="introduction.html">Introduction</a></li><li><a href="installation.html">Installation</a></li><li><a href="deployment.html">Deployment</a></li><li><a href="source.html">Source Code</a></li><li><a href="processes.html">Processes</a></li><li><a href="sample/">Example App</a></li></ul></div></nav></div></div><div id="mainRight"><div id="content"><h2>Deployment</h2><h3 id="Table_of_Contents">Table of Contents</h3><div class="text">
|
|
<ul><li><a href="#Background">Background</a></li><li><a href="#Standard_Directory_Layout">Standard Directory Layout</a></li><li><a href="#Shared_Library_Files">Shared Library Files</a></li><li><a href="#Web_Application_Deployment_Descriptor">Web Application Deployment Descriptor</a></li><li><a href="#Tomcat_Context_Descriptor">Tomcat Context Descriptor</a></li><li><a href="#Deployment_With_Tomcat">Deployment With Tomcat</a></li></ul>
|
|
</div><h3 id="Background">Background</h3><div class="text">
|
|
|
|
<p>Before describing how to organize your source code directories,
|
|
it is useful to examine the runtime organization of a web application.
|
|
Prior to the Servlet API Specification, version 2.2, there was little
|
|
consistency between server platforms. However, servers that conform
|
|
to the 2.2 (or later) specification are required to accept a
|
|
<em>Web Application Archive</em> in a standard format, which is discussed
|
|
further below.</p>
|
|
|
|
<p>A web application is defined as a hierarchy of directories and files
|
|
in a standard layout. Such a hierarchy can be accessed in its "unpacked"
|
|
form, where each directory and file exists in the filesystem separately,
|
|
or in a "packed" form known as a Web ARchive, or WAR file. The former format
|
|
is more useful during development, while the latter is used when you
|
|
distribute your application to be installed.</p>
|
|
|
|
<p>The top-level directory of your web application hierarchy is also the
|
|
<em>document root</em> of your application. Here, you will place the HTML
|
|
files and JSP pages that comprise your application's user interface. When the
|
|
system administrator deploys your application into a particular server, they
|
|
assign a <em>context path</em> to your application (a later section
|
|
of this manual describes deployment on Tomcat). Thus, if the
|
|
system administrator assigns your application to the context path
|
|
<code>/catalog</code>, then a request URI referring to
|
|
<code>/catalog/index.html</code> will retrieve the <code>index.html</code>
|
|
file from your document root.</p>
|
|
|
|
</div><h3 id="Standard_Directory_Layout">Standard Directory Layout</h3><div class="text">
|
|
|
|
<p>To facilitate creation of a Web Application Archive file in the required
|
|
format, it is convenient to arrange the "executable" files of your web
|
|
application (that is, the files that Tomcat actually uses when executing
|
|
your app) in the same organization as required by the WAR format itself.
|
|
To do this, you will end up with the following contents in your
|
|
application's "document root" directory:</p>
|
|
<ul>
|
|
<li><strong>*.html, *.jsp, etc.</strong> - The HTML and JSP pages, along
|
|
with other files that must be visible to the client browser (such as
|
|
JavaScript, stylesheet files, and images) for your application.
|
|
In larger applications you may choose to divide these files into
|
|
a subdirectory hierarchy, but for smaller apps, it is generally
|
|
much simpler to maintain only a single directory for these files.
|
|
<br><br></li>
|
|
<li><strong>/WEB-INF/web.xml</strong> - The <em>Web Application Deployment
|
|
Descriptor</em> for your application. This is an XML file describing
|
|
the servlets and other components that make up your application,
|
|
along with any initialization parameters and container-managed
|
|
security constraints that you want the server to enforce for you.
|
|
This file is discussed in more detail in the following subsection.
|
|
<br><br></li>
|
|
<li><strong>/WEB-INF/classes/</strong> - This directory contains any Java
|
|
class files (and associated resources) required for your application,
|
|
including both servlet and non-servlet classes, that are not combined
|
|
into JAR files. If your classes are organized into Java packages,
|
|
you must reflect this in the directory hierarchy under
|
|
<code>/WEB-INF/classes/</code>. For example, a Java class named
|
|
<code>com.mycompany.mypackage.MyServlet</code>
|
|
would need to be stored in a file named
|
|
<code>/WEB-INF/classes/com/mycompany/mypackage/MyServlet.class</code>.
|
|
<br><br></li>
|
|
<li><strong>/WEB-INF/lib/</strong> - This directory contains JAR files that
|
|
contain Java class files (and associated resources) required for your
|
|
application, such as third party class libraries or JDBC drivers.</li>
|
|
</ul>
|
|
|
|
<p>When you install an application into Tomcat (or any other 2.2 or later
|
|
Servlet container), the classes in the <code>WEB-INF/classes/</code>
|
|
directory, as well as all classes in JAR files found in the
|
|
<code>WEB-INF/lib/</code> directory, are made visible to other classes
|
|
within your particular web application. Thus, if
|
|
you include all of the required library classes in one of these places (be
|
|
sure to check licenses for redistribution rights for any third party libraries
|
|
you utilize), you will simplify the installation of your web application --
|
|
no adjustment to the system class path (or installation of global library
|
|
files in your server) will be necessary.</p>
|
|
|
|
<p>Much of this information was extracted from Chapter 9 of the Servlet
|
|
API Specification, version 2.3, which you should consult for more details.</p>
|
|
|
|
</div><h3 id="Shared_Library_Files">Shared Library Files</h3><div class="text">
|
|
|
|
<p>Like most servlet containers, Tomcat also supports mechanisms to install
|
|
library JAR files (or unpacked classes) once, and make them visible to all
|
|
installed web applications (without having to be included inside the web
|
|
application itself). The details of how Tomcat locates and shares such
|
|
classes are described in the
|
|
<a href="../class-loader-howto.html">Class Loader How-To</a> documentation.
|
|
The location commonly used within a Tomcat installation for shared code is
|
|
<strong>$CATALINA_HOME/lib</strong>. JAR files placed here are visible both to
|
|
web applications and internal Tomcat code. This is a good place to put JDBC
|
|
drivers that are required for both your application or internal Tomcat use
|
|
(such as for a DataSourceRealm).</p>
|
|
|
|
<p>Out of the box, a standard Tomcat installation includes a variety
|
|
of pre-installed shared library files, including:</p>
|
|
<ul>
|
|
<li>The <em>Servlet 6.0</em> and <em>JSP 4.0</em> APIs that are fundamental
|
|
to writing servlets and JSPs.<br><br></li>
|
|
</ul>
|
|
|
|
</div><h3 id="Web_Application_Deployment_Descriptor">Web Application Deployment Descriptor</h3><div class="text">
|
|
|
|
<p>As mentioned above, the <code>/WEB-INF/web.xml</code> file contains the
|
|
Web Application Deployment Descriptor for your application. As the filename
|
|
extension implies, this file is an XML document, and defines everything about
|
|
your application that a server needs to know (except the <em>context path</em>,
|
|
which is assigned by the system administrator when the application is
|
|
deployed).</p>
|
|
|
|
<p>The complete syntax and semantics for the deployment descriptor is defined
|
|
in Chapter 13 of the Servlet API Specification, version 2.3. Over time, it
|
|
is expected that development tools will be provided that create and edit the
|
|
deployment descriptor for you. In the meantime, to provide a starting point,
|
|
a <a href="web.xml.txt" target="_blank">basic web.xml file</a>
|
|
is provided. This file includes comments that describe the purpose of each
|
|
included element.</p>
|
|
|
|
<p><strong>NOTE</strong> - The Servlet Specification includes a Document
|
|
Type Descriptor (DTD) for the web application deployment descriptor, and
|
|
Tomcat enforces the rules defined here when processing your application's
|
|
<code>/WEB-INF/web.xml</code> file. In particular, you <strong>must</strong>
|
|
enter your descriptor elements (such as <code><filter></code>,
|
|
<code><servlet></code>, and <code><servlet-mapping></code> in
|
|
the order defined by the DTD (see Section 13.3).</p>
|
|
|
|
</div><h3 id="Tomcat_Context_Descriptor">Tomcat Context Descriptor</h3><div class="text">
|
|
|
|
<p>A /META-INF/context.xml file can be used to define Tomcat specific
|
|
configuration options, such as an access log, data sources, session manager
|
|
configuration and more. This XML file must contain one Context element, which
|
|
will be considered as if it was the child of the Host element corresponding
|
|
to the Host to which the web application is being deployed. The
|
|
<a href="../config/context.html">Tomcat configuration documentation</a> contains
|
|
information on the Context element.</p>
|
|
|
|
</div><h3 id="Deployment_With_Tomcat">Deployment With Tomcat</h3><div class="text">
|
|
|
|
<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 $CATALINA_HOME,
|
|
the directory into which you have installed Tomcat.</em></p>
|
|
|
|
<p>In order to be executed, a web application must be deployed on
|
|
a servlet container. This is true even during development.
|
|
We will describe using Tomcat to provide the execution environment.
|
|
A web application can be deployed in Tomcat by one of the following
|
|
approaches:</p>
|
|
<ul>
|
|
<li><em>Copy unpacked directory hierarchy into a subdirectory in directory
|
|
<code>$CATALINA_BASE/webapps/</code></em>. Tomcat will assign a
|
|
context path to your application based on the subdirectory name you
|
|
choose. We will use this technique in the <code>build.xml</code>
|
|
file that we construct, because it is the quickest and easiest approach
|
|
during development. Be sure to restart Tomcat after installing or
|
|
updating your application.
|
|
<br><br></li>
|
|
<li><em>Copy the web application archive file into directory
|
|
<code>$CATALINA_BASE/webapps/</code></em>. When Tomcat is started, it will
|
|
automatically expand the web application archive file into its unpacked
|
|
form, and execute the application that way. This approach would typically
|
|
be used to install an additional application, provided by a third party
|
|
vendor or by your internal development staff, into an existing
|
|
Tomcat installation. <strong>NOTE</strong> - If you use this approach,
|
|
and wish to update your application later, you must both replace the
|
|
web application archive file <strong>AND</strong> delete the expanded
|
|
directory that Tomcat created, and then restart Tomcat, in order to reflect
|
|
your changes.
|
|
<br><br></li>
|
|
<li><em>Use the Tomcat "Manager" web application to deploy and undeploy
|
|
web applications</em>. Tomcat includes a web application, deployed
|
|
by default on context path <code>/manager</code>, that allows you to
|
|
deploy and undeploy applications on a running Tomcat server without
|
|
restarting it. See <a href="../manager-howto.html">Manager App How-To</a>
|
|
for more information on using the Manager web application.<br><br></li>
|
|
<li><em>Use "Manager" Ant Tasks In Your Build Script</em>. Tomcat
|
|
includes a set of custom task definitions for the <code>Ant</code>
|
|
build tool that allow you to automate the execution of commands to the
|
|
"Manager" web application. These tasks are used in the Tomcat deployer.
|
|
<br><br></li>
|
|
<li><em>Use the Tomcat Deployer</em>. Tomcat includes a packaged tool
|
|
bundling the Ant tasks, and can be used to automatically precompile JSPs
|
|
which are part of the web application before deployment to the server.
|
|
<br><br></li>
|
|
</ul>
|
|
|
|
<p>Deploying your app on other servlet containers will be specific to each
|
|
container, but all containers compatible with the Servlet API Specification
|
|
(version 2.2 or later) are required to accept a web application archive file.
|
|
Note that other containers are <strong>NOT</strong> required to accept an
|
|
unpacked directory structure (as Tomcat does), or to provide mechanisms for
|
|
shared library files, but these features are commonly available.</p>
|
|
|
|
</div></div></div></div></div><footer><div id="footer">
|
|
Copyright © 1999-2024, The Apache Software Foundation
|
|
<br>
|
|
Apache Tomcat, Tomcat, Apache, the Apache Tomcat logo and the Apache logo
|
|
are either registered trademarks or trademarks of the Apache Software
|
|
Foundation.
|
|
</div></footer></div></body></html> |