Generally speaking,it's very simple to migrate apps from tomcat to jboss because the web container of jboss is tomcat.
But for the specialty in your app,i just show some sugguests as follows:
1) Datasource: you can use jboss jndi by defining *-ds.xml under deploy/;
2) Log: you can use Log4j.xml in your app or jboss-log4j.xml under the directory $JBOSS_HOME/server/default/jboss-log4j.xml.
3) others: you can define something in jboss-web.xml which places in the app.war/WEB-INF/ derectory.