Embedded Tomcat in Maven enable SSI support

As in one of my projects I needed to run a Tomcat server for later deployment of the webapp, I decided to use an embedded variant of the tomcat server in maven.

This works really fine as you can just use a maven plugin:

<build>
<finalName>project</finalName>
<outputDirectory>src/main/webapp/WEB-INF/classes</outputDirectory>
<!-- To use the plugin goals in your POM or parent POM -->
<plugins>
 <plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>tomcat-maven-plugin</artifactId>
  <configuration>
   <mode>both</mode>
   <systemProperties>
    <org.apache.catalina.level>FINEST</org.apache.catalina.level>
   </systemProperties>
  </configuration>
 </plugin>
</plugins>
</build>

Important here is to add the extra configuration with mode set to both, i.e. allowing to deploy a given context.xml.

This context.xml is needed to tell tomcat that this webapp needs to be executed in provileged mode. (thus privileged="true" )

Otherwise we would get ane xception like this:
Servlet of class org.apache.catalina.ssi.SSIServlet is privileged and cannot be loaded by this web application

So lets create a context.xml under the META-INF (if not existant create it) in the webapp directory:

context.xml

<?xml version="1.0" encoding="UTF-8"?>
<Context antiResourceLocking="false" privileged="true" useHttpOnly="true" />

Lets now configure our web.xml in order to detect .shtml files and process the SSI inside of them.

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
   
    <display-name>app</display-name>
   
<!-- SSI -->

    <servlet>
         <servlet-name>ssi</servlet-name>
         <servlet-class>org.apache.catalina.ssi.SSIServlet</servlet-class>
         <init-param>
              <param-name>buffered</param-name>
              <param-value>0</param-value>
         </init-param>
         <init-param>
              <param-name>debug</param-name>
              <param-value>1</param-value>
         </init-param>
         <init-param>
              <param-name>expires</param-name>
              <param-value>1</param-value>
         </init-param>
         <init-param>
              <param-name>isVirtualWebappRelative</param-name>
              <param-value>1</param-value>
         </init-param>
         <load-on-startup>4</load-on-startup>
    </servlet>

    <servlet-mapping>
         <servlet-name>ssi</servlet-name>
         <url-pattern>*.shtml</url-pattern>
    </servlet-mapping>

    <mime-mapping>
         <extension>shtml</extension>
         <mime-type>text/html</mime-type>
    </mime-mapping>
   
</web-app>

As you can see we used the SSI Servlet instead of the SSI Filter, which also could be used. Just look into the documentation of tomcat server.

Important: We need to set the mime type differently than the official documentation says. Otherwise FireFox (tested in 4/5) won't detect the document and instead trys to download it.

Thats all of it!