It doesn't complain that it cannot write, it complains that it cannot
read. As pointed out by petrojn, it is because you run with security
manager enabled and it prevents the webapp from accessing that file.
For your own applications, that's something you should set by adding
files to /etc/tomcat5
It's probably worth reading
http://tomcat.apache.org/tomcat-5.5-doc/security-manager-howto.html
and configuring files in /etc/tomcat5.5/policy.d
and if you are not worried about security then disabling it in the
/etc/init.d/tomcat5.5 file is the way to go by setting this option:
TOMCAT5_SECUR
The problem occurs also with new webapps. For example, when I copy
tomcat-docs/appdev/sample/sample.war to
/var/lib/tomcat5.5/webapps
I get errors in the log-file, among which:
Caused by: java.security.AccessControlException: access denied
(java.io.FilePermission /var/lib/tomcat5.5/webapps/samp