Writing and Reading a text file from Elasticsearch Plugin

Hi,

I am working on a plugin, which generates meta-data from indexed documents. During the generation of this meta-data, I want to store some temporary data in a file and again read that file in future. The output of the plugin is very different from the content of the file.

I have tried giving permission permission java.io.FilePermission "D:\\Projects\\accuracy_file.txt","write"; in java-security.policy file and I am still getting this error access denied ("java.io.FilePermission" "D:\Projects\accuracy_file.txt" "write"). The file has to be generated because it may also be used by some other (not ES) services.

Please help me figure out a way out.
Thanks in advance
E.