Mapping address to multiple tomcat instances
It is quite common to use multiple Tomcats behind Apache to do load balancing. While this is not load balancing the principle is the same. Instead of having one application with 3 load-balanced Tomcat workers, you would have 3 applications with 1 tomcat worker each.
You can find the tomcat documentation here: http://tomcat.apache.org/connectors-doc/
Try mod proxy configuration on below code in httpd:
ProxyPass /app0 http://localhost:8080/app0/ProxyPassReverse /app0 http://localhost:8080/app0/ProxyPass /app1 http://localhost:8081/app1/ProxyPassReverse /app1 http://localhost:8081/app1/ProxyPass /app2 http://localhost:8082/app2/ProxyPassReverse /app2 http://localhost:8082/app2/