Unable to create and write data to a file.

I am calling a java action, after that am coming to eclipse, In ecplise In a class where we have "// BEGIN USER CODE"       and    "// END USER CODE"  inside this I am trying to create a .txt  file and want to write some data on it . I tried lot of thing but I am getting below exception.

com.mendix.modules.microflowengine.MicroflowException: com.mendix.core.CoreRuntimeException:

com.mendix.systemwideinterfaces.MendixRuntimeException: java.security.AccessControlException: access denied

("java.io.FilePermission" "D:\test123.txt" "write")
    at MyFirstModule.Test12 (JavaAction : 'Test')