Struts 2 on GAE – java.security.AccessControlException: access denied

Problem

Developing Struts2 (v 2.3.1.2) on Google App Engine (SDK v1.6.3.1), local development, hit “java.security.AccessControlException: access denied” error?

Solution

Normally, this is because you turn the “devMode on” in struts.xml file.

File : struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
 
<struts>
	<constant name="struts.devMode" value="true" /> 
	//...
</struts>

When you turn devMode on, Struts2 will try to write to the disk for logging, which is denied by GAE, it can only write to Google data store.

To solve it, you have to delete the devMode statement in your struts.xml file.

Reference

1. struts 2.1.8 met AccessControlException with app engine’s local server