Shared Data files, Java

On Windows (Vista and up, at least) the correct place to store shared data for applications is %ProgramData% . For example, say we want MaxMind's GeoLite2 database file available to several applications. It should go at %ProgramData%\maxmind\GeoLite2-City.mmdb .

On Ubuntu, the correct place to store shared program data is /srv . So GeoLite would go at /srv/maxmind/GeoLite2-City.mmdb .

It would be nice in Java to have a cross-platform system property to access these locations easily. Here's how.

In Windows:

setx JAVA_TOOL_OPTIONS "%JAVA_TOOL_OPTIONS% -Dshared.data=%ProgramData%" -m

In Ubuntu:

sudo nano /etc/environment

Add/update the following:

JAVA_TOOL_OPTIONS=-Dshared.data=/srv

Then in a Java/Spring program you can use the system property like:

${shared.data}/maxmind/GeoLite2-City.mmdb