Installing it in your webapp is very easy.
In your pom add a dependency :
<dependency>
<groupId>net.bull.javamelody</groupId>
<artifactId>javamelody-core</artifactId>
<version>1.16.0</version>
</dependency>
This dependency is not in central repo so you have to add two repository in youe favorite repository manager.
* http://maven.glassfish.org/content/groups/public/
* http://repo.opennms.org/maven2
In your webapp add the following entries
<listener>
<listener-class>net.bull.javamelody.SessionListener</listener-class>
</listener>
<filter>
<filter-name>monitoring</filter-name>
<filter-class>net.bull.javamelody.MonitoringFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>monitoring</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
Hit your browser at http://ip:port/context/monitoring
The display is similar to the tool called orca but on real time.