Wildfly has a development mode for JSP. In development mode, the wildfly server will check for changes in JSP files in deployed applications. JSPs can therefore be edited and tested without recompiling and redeploying the entire war file. Very handy.
This is configured in ${WILDFLY_ROOT}/standalone/configuration/standalone.xml. To enable it, set the development attribute to true in the element <jsp-config>.
<subsystem xmlns="urn:jboss:domain:undertow:1.2">
<servlet-container name="default">
<jsp-config development="true" tag-pooling="false"/>
</servlet-container>
</subsystem>
If the original war file is deployed with maven, the exploded application can be find in ${WILDFLY_ROOT}/standalone/tmp/vfs/temp/tempxxxxxxx/content-xxxxxxx, where xxxxxxx is a series of random numbers. The JSPs should be in the WEB-INF directory under the application root. Replacing a JSP with a newer version and changes are immediately reflected when the webpage is reloaded.