How to test webapp

Using Maven & embedded Apache Tomcat (by plugin)

Open Maven Projects facet (at the right of IDEA), then double-click:

clean (if something previously generated at target/)
package (build war, found at target/javacourse181112-1.0-SNAPSHOT.war)
tomcat7 -> run-war (right-click, run or debug mode)

Using pre-installed Apache Tomcat

Hot deploy (cp-paste war file at webapp dir; Tomcat is constantly watching webapps for new war archives to deploy)

Using Manager web application, distributed (usually) with Tomcat

Using Application Servers IDEA's integration (only available with Intellij IDEA Enterprise Edition)