Installing Web Applications

A context is a name that gets mapped to a Web application. For example, the context of the hello1 application is /hello1. To install an application into Tomcat, you notify Tomcat that a new context is available. Note that an installed application is not available after Tomcat is restarted. To permanently deploy an application you invoke the manager application deploy command (see Deploying Web Applications). Installing an application is the recommended operation when you are iteratively developing an application because you do not have to package the WAR and because you can quickly reload an updated application.

You install an application into Tomcat with the manager application install command invoked via the Ant install task. The Ant install task tells the manager running at the location specified by the url attribute to install an application at the context specified by the path attribute and the location containing the Web application files specified with the war attribute. The value of the war attribute can be a WAR file jar:file:/path/to/bar.war!/ or an unpacked directory file:/path/to/foo.

<install url="url" path="mywebapp" war="file:build"
  username="username" password="password" />

Instead of providing a war attribute, you can specify configuration information with the config attribute:

<install url="url" 
  path="mywebapp" config="file:build/context.xml"
  username="username" password="password"/>

The config attribute points to a configuration file that contains a context entry of the form:

<Context path="/bookstore1"
  docBase="../../jwstutorial12/examples/web/bookstore1/build"
  debug="0">

Note that the context entry specifies the location of the Web application through its docBase attribute.

The tutorial example build files contain an Ant install and install-config targets that invoke the Ant install task:

<target name="install" 
  description="Install web application" depends="build">
  <install url="${url}" path="${mywebapp}"
    war="file:build"
    username="${username}" password="${password}"/>
</target> 
<target name="install-config" 
  description="Install web application" depends="build">
  <install url="${url}" path="${mywebapp}"
    config="file:build/context.xml"
    username="${username}" password="${password}"/>
</target>

These tasks require that a Web application deployment descriptor be available. All of the tutorial examples are distributed with a deployment descriptor.

In a terminal window, go to <INSTALL>/jwstutorial12/examples/web/hello1.

Make sure Tomcat is started.

Execute ant install. The install target notifies Tomcat that the new context is available.