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1. Modify <geronimo-directory>\var\catalina\conf\web.xml:
- Set the development parameter to true in the init-param to org.apache.jasper.servlet.JspServlet
- Edit (add if doesn't exist) the modificationTestInterval to 0
2. In the webapp that you intend to modify, find the web.xml and remove the servlet-name and servlet-mapping of the jsp you intend to modify and test.
For example, for PlanCreator I edit the plancreator-console-tomcat-2.2-SNAPSHOT.car\WEB-INF\web.xml.
3. Restart the server with these settings in place.
Once this is done, you can modify the jsp in place and hit refresh to test it. It'll be recompiled each time.