google app engine - java.security.AccessControlException: access denied ("java.io.FilePermission" "C:\tempFolder" "read") on GAE -

google app engine - java.security.AccessControlException: access denied ("java.io.FilePermission" "C:\tempFolder" "read") on GAE -

i migrating application tomcat google app engine (1.9.1) running jsf 2.2 on servlet 2.5 , facing issue reading files file system, have code creates file on file scheme follows:

file file = new file("c:\\tempfolder"); if(file.isdirectory()){ // writing stuff here }

on tomcat not getting exceptions on above code, on google app engine getting next exception:

caused by: java.security.accesscontrolexception: access denied ("java.io.filepermission" "c:\tempfolder" "read") @ java.security.accesscontrolcontext.checkpermission(accesscontrolcontext.java:372) @ java.security.accesscontroller.checkpermission(accesscontroller.java:559) @ java.lang.securitymanager.checkpermission(securitymanager.java:549) @ com.google.appengine.tools.development.devappserverfactory$customsecuritymanager.checkpermission(devappserverfactory.java:429)

please advise why getting exception , how prepare it.

why getting exception

gae environment sandboxed number of reasons. means cannot lot of things on local machine.

this includes write access file system.

how prepare it

find way persist info (database, example).

you can read little bit more on sandbox restrictions here.

java google-app-engine java-ee